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Question Use GCR spectrum wiht GPS   by payam <payam>,   Aug 22, 03:22
Dear All

I want to us GCR proton spectrum in GPS, but I am not sure how can I do that. This is parts of the spectrum that I have

# MeV #particles/m^2/s/sr/MeV

1.06100922715098 1.269442e-02

1.19047193304807 1.510311e-02

1.33573147820846 1.7961127e-02

1.49871536854193 2.13549999e-02

1.68158630125002 2.53869984e-02

1.8867708625039 3.0176143e-02

...

My question is, should I normalize my data for m^2/s/sr/MeV or I do not need that and I can use this spectrum as input like

# ********************************
#  Particle type: downward protons
# *********************************
/gps/particle proton

/gps/pos/type Surface

/gps/pos/shape Sphere

/gps/pos/centre 0.251 -165.749 -129.3 mm

/gps/pos/radius 16. cm

#####################

/gps/ene/diffspec 1

/gps/ene/type Arb

/gps/hist/type arb

####################

/gps/hist/point 1.06100922715098 1.269442e-02

/gps/hist/point 1.19047193304807 1.510311e-02

/gps/hist/point 1.33573147820846 1.7961127e-02

/gps/hist/point 1.49871536854193 2.13549999e-02

/gps/hist/point 1.68158630125002 2.53869984e-02

/gps/hist/point 1.8867708625039 3.0176143e-02

...

/gps/hist/inter Lin

Thanks in advance for your help,

Question Adding multiple SPENVIS GCR Spectra to 1 GPS macro file  by David Hodge <David Hodge>,   Jun 26, 03:38
Hi All,

I've used SPENVIS to generate GCR spectra for an interplanetary trajectory based on ISO 15390. It works great, but only outputs 1 species at a time. I've successfully added multiple species spectra to a macro file, but I'm struggling with how to normalize more than one source at a time. So:

1. Is there a way to use the /control/alias NORM_FACTOR_SPECTRUM " " command sequence multiple times in the same macro?

2. Is it accurate to take the spectrum normalization factor generated by SPENVIS and use it for source intensity? The proportions of protons to other nuclei seem to work if these numbers are used, but this doesn't seem correct to me. Anybody know where you can get relative intensities for a multi-species GCR source macro?

Thanks, -D. Hodge

None Re: Adding multiple SPENVIS GCR Spectra to 1 GPS macro file  by Hugh Evans <Hugh Evans>,   Jun 27, 02:45
Re: Question Adding multiple SPENVIS GCR Spectra to 1 GPS macro file (David Hodge)
Hi David,

At this point SPENVIS only generates a macro file for a single ion species. However, it is possible to construct a macro file with multiple sources. For an example, see the MC-SCREAM model under radiation sources and effects/solar cell radiation damage. MC-SCREAM creates a macro file with the trapped electron, trapped proton and solar proton sources.

With this method, the normalisation factor for each source is set via the "/gps/source/intensity" macro, and the overall normalisation is set with the "/analysis/normalise" macro, which should be the sum of the various intensities.

For example:
# Trapped protons:
/gps/particle proton
/gps/ene/type Arb
/gps/ene/diffspec true
/gps/hist/type arb
/gps/ene/min 1.000E-01 MeV
/gps/ene/max 2.000E+00 MeV
/gps/source/intensity 3.645E+14
/gps/hist/point 1.000E-01 6.125E+07
...
# Trapped electrons:
/gps/source/add 1
/geometry/setGPSsource
/gps/particle e-
/gps/ene/type Arb
/gps/ene/diffspec true
/gps/hist/type arb
/gps/ene/min 9.200E-04 MeV
/gps/ene/max 3.970E+00 MeV
/gps/source/intensity 7.472E+16
/gps/hist/point 9.200E-04 1.872E+11
...
# Solar protons
/gps/source/add 1
/geometry/setGPSsource
/gps/particle proton
/gps/ene/type Arb
/gps/ene/diffspec true
/gps/hist/type arb
/gps/ene/min 1.000E-01 MeV
/gps/ene/max 5.000E+02 MeV
/gps/source/intensity 2.866E+11
/gps/hist/point 1.000E-01 1.005E+13
...
# Overall Normalisation factor
/analysis/normalise 7.508E+16 cm2


Regards Hugh
None Re: Adding multiple SPENVIS GCR Spectra to 1 GPS macro file  by David Hodge <David Hodge>,   Jun 28, 01:15
Re: None Re: Adding multiple SPENVIS GCR Spectra to 1 GPS macro file (Hugh Evans)
Hi Hugh,

Thanks very much for the clarification; I'll see about modifying the multi-source GCR macro accordingly.

Cheers, -D. Hodge

None tallies/analysis mapping between GRAS and MCNP  by Svetlana Shasharina <Svetlana Shasharina>,   May 29, 14:16
Hi everybody,

If I wanted to compare GRAS (G4) and MCNP6.2, what would be the mapping 
between scoring/tallies?

I thing that dose of GRAS corresponds to F6 (energy deposition) and 
fluence of GRAS maps to F4 of MCNP?

What would be GRAS version of a surface flux of MCNP F2?

Best regards,

Sveta


-- 
Svetlana Shasharina                            | sveta@txcorp.com
Vice-President of Computational Infrastructure | Tech-X Corporation
Idea Re: tallies/analysis mapping between GRAS and MCNP  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   Jul 04, 05:04
Re: None tallies/analysis mapping between GRAS and MCNP (Svetlana Shasharina)
Hello,

unfortunately, majority of Geant4 peoples never run MCMP. Comparisons between these two tools usually were performed by independent users. GRAS is an application built on top of Geant4, it includes analysis modules which are needed for space application. There were no attempt reproduce MCMP analysis.

VI

None Re: tallies/analysis mapping between GRAS and MCNP  by Svetlana Shasharina <Svetlana Shasharina>,   Jul 04, 06:27
Re: Idea Re: tallies/analysis mapping between GRAS and MCNP (Vladimir Ivanchenko)
Thank you, Vladimir!

We think that there is  a straightforward mapping for TID (energy dep) 
and volume fluxes/currents, but I am struggling with a surface current.

GRAS has examples of mesh tallies calculating flat surface current/flux 
(under tests/mesh_scoring), but it produces zeros (I had to comment out 
the line setting up the units as GRAS crashed for me there).

Another user (copied) gets this message:

[GRASAnalysisModule::SetUnit] ERROR: No conversion factor available for 
unit: mm [GRASAnalysisModule::SetUnit] WARNING: Keeping unit: Looks like 
Sergio Ibarmia Huete developed these scorings (flat surface/flux) and I 
hope to get in contact with him. If you happen to know his email, could 
you share with me off list? Best, Svetlana


On 7/4/18 6:04 AM, Vladimir Ivanchenko wrote:
> *** Discussion title: Space Applications
>
> Hello,
>
> unfortunately, majority of Geant4 peoples never run MCMP. Comparisons
> between these two tools usually were performed by independent users.
> GRAS is an application built on top of Geant4, it includes analysis
> modules which are needed for space application. There were no attempt
> reproduce MCMP analysis.
>
> VI
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/136/1.html
>


 [ MIME part of type text/html without a name stripped ]

Question Simulating Co60 source environment in GRAS  by Leonardo Ghizoni <Leonardo Ghizoni>,   10 Mar, 2018
Hello,

In the context of Total Ionizing Dose, I wonder if it is possible in GRAS to simulate a Cobalt 60 source, so I can better understand the amount of needed shielding for a given component in space.

Is it just by declaring the Ion Cobalt 60 and decay physics lists? Then I would wish to have the incident 1.17 MeV and 1.33 MeV gamma-rays.

I know I can just shoot the gamma-rays, but I wonder if nuclear decay with the products is possible in GRAS.

Thanks a lot in advance.

/Leonardo.

Idea Re: Simulating Co60 source environment in GRAS  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   Jul 04, 05:12
Re: Question Simulating Co60 source environment in GRAS (Leonardo Ghizoni)
Hello,

sorry for the late response. To enable radioactive decay the line should be added in macro file:

/gras/physics/addPhysics raddecay

to start primary Co60

/gun/particle ion /gun/ion 27 60

VI

None mesh scoring in GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   06 Dec, 2017
Hi, Is it possible to have mesh scoring in GRAS? Thank you, Sveta

Idea Re: mesh scoring in GRAS  by Leonardo Ghizoni <Leonardo Ghizoni>,   May 11, 10:06
Re: None mesh scoring in GRAS (Svetlana Shasharina)
Hi,

Assuming you have GRAS installed, I suggest you to take a look at $GRAS_dir/tests/mesh_scoring/. There you'll find a good example of mesh scoring with GRAS.

Hope it helps.

Regards, Leonardo.

None Re: mesh scoring in GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   Jul 05, 10:00
Re: Idea Re: mesh scoring in GRAS (Leonardo Ghizoni)
Dear Leonardo,

This example contains /gras/score/quantity/flatSurfaceFlux fluxTotal 1 
command which does not produce any output related to this scorer.

Have you tried to calculate flat surface flux/current using GRAS?

Thank you,

Sveta


On 5/11/18 11:06 AM, Leonardo Ghizoni wrote:
> *** Discussion title: Space Applications
>
> Hi,
>
> Assuming you have GRAS installed, I suggest you to take a look at
> $GRAS_dir/tests/mesh_scoring/. There you'll find a good example of mesh
> scoring with GRAS.
>
> Hope it helps.
>
> Regards, Leonardo.
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/134/1.html
>

-- 
Svetlana Shasharina                            | sveta@txcorp.com
Vice-President of Computational Infrastructure | Tech-X Corporation
None Re: mesh scoring in GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   Jul 05, 10:50
Re: None Re: mesh scoring in GRAS (Svetlana Shasharina)
I just realized that this example explicitly sets up all mesh cells in 
the gdml file.  This would be very difficult for a large mesh.

If there a way to use  g4 in the gras mac file?

I tried to run gras with the following:

/process/verbose 0
/control/verbose 1
/tracking/verbose 0
/event/verbose 0
/run/verbose 0

# ------- Physics ---------

/gras/physics/setCuts 0.1 mm
/gras/physics/addPhysics em_standard

# ------- Primaries -------

/gps/position 250 0 0 cm
/gps/direction -1 0 0
/gps/particle e-
/gps/energy 3.0 MeV

/score/create/boxMesh boxMesh_1
/score/mesh/boxSize 100. 100. 100. cm
/score/mesh/nBin 30 30 30
/score/quantity/energyDeposit eDep
/score/quantity/flatSurfaceFlux fluxTotal 1
/score/close
/score/list

/run/initialize

/run/beamOn 1000

and got:

***** COMMAND NOT FOUND </score/create/boxMesh boxMesh_1> *****

Thank you,
Sveta

On 7/5/18 11:00 AM, Svetlana G. Shasharina wrote:
> *** Discussion title: Space Applications
>
> Dear Leonardo,
>
> This example contains /gras/score/quantity/flatSurfaceFlux fluxTotal 1
> command which does not produce any output related to this scorer.
>
> Have you tried to calculate flat surface flux/current using GRAS?
>
> Thank you,
>
> Sveta
>
> On 5/11/18 11:06 AM, Leonardo Ghizoni wrote:
>> *** Discussion title: Space Applications
>>
>> Hi,
>>
>> Assuming you have GRAS installed, I suggest you to take a look at
>> $GRAS_dir/tests/mesh_scoring/. There you'll find a good example of mesh
>> scoring with GRAS.
>>
>> Hope it helps.
>>
>> Regards, Leonardo.
>>
>> -------------------------------------------------------------
>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/134/1.html
>>

-- 
Svetlana Shasharina                            | sveta@txcorp.com
Vice-President of Computational Infrastructure | Tech-X Corporation
None Re: mesh scoring in GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   May 29, 12:06
Re: Idea Re: mesh scoring in GRAS (Leonardo Ghizoni)
Hello Leonardo,

In order to run

gras runMeshScore.mac

I had to comment out these two lines:


/gras/score/create/gdml/setup Default

/gras/score/create/gmsh/lengthUnit mm

It ran after that.

Thank you,
Sveta


On 5/11/18 11:06 AM, Leonardo Ghizoni wrote:
> *** Discussion title: Space Applications
>
> Hi,
>
> Assuming you have GRAS installed, I suggest you to take a look at
> $GRAS_dir/tests/mesh_scoring/. There you'll find a good example of mesh
> scoring with GRAS.
>
> Hope it helps.
>
> Regards, Leonardo.
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/134/1.html
>

-- 
Svetlana Shasharina                            | sveta@txcorp.com
Vice-President of Computational Infrastructure | Tech-X Corporation
Question Extreme Ultraviolet simulation  by Gianluca De Zanet <Gianluca De Zanet>,   27 Sep, 2017
Hi everyone, I'm a newbie with Geant4 and the environments it could simulate, so better asking directly: is it possible to simulate the UV environment or its energy is too low for Geant4? Thank you,

Gianluca

None Re: Extreme Ultraviolet simulation  by ali atwa <ali atwa>,   Sep 05, 23:58
Re: Question Extreme Ultraviolet simulation (Gianluca De Zanet)
I'm also seeking for the same answer


TheRecap
None Re: Extreme Ultraviolet simulation  by <php1ic>,   29 Sep, 2017
Re: Question Extreme Ultraviolet simulation (Gianluca De Zanet)
I've also not had experience with UV energies, but from work I have done in the ~10keV range, pay close attention to the cuts values in your PhysicsList. the defaults may be far too large.

Note Re: Extreme Ultraviolet simulation  by Tim Meehan <Tim Meehan>,   28 Sep, 2017
Re: Question Extreme Ultraviolet simulation (Gianluca De Zanet)
UV is not something that I have much experience with, but searching Google with "geant4 uv light" came up with several examples: https://twiki.cern.ch/twiki/bin/view/Geant4/AdvancedExamplesAirShower

Question non-spherical sources for estimating geometric factor  by Elias Roussos <Elias Roussos>,   20 Sep, 2017
Hi,

I am trying to estimate the geometry factor of a particle telescope. &#913; macro file used for the input particles is:

/gps/particle e- /gps/pos/type Surface /gps/pos/shape Sphere /gps/centre 0 0 0 cm /gps/pos/radius 20 cm /gps/ang/type cos /gps/ene/mono 50. keV

If I use this, I can calculate the GF of the sensitive detector as:

GF = 4*PI^2*(Radius)^2*(N_detected/N_source)

and I get a result close to the expected value.

When I make a run with low energy particles that cannot penetrate the instrument shielding, it is enough to inject the paticles only from a surface in front of the collimator/telescope entrance, just to improve statistics. I defined a spherical cap with an opening e.g. of 60 deg like this:

/gps/hist/type biaspt

/gps/hist/point 0.0 0.0

/gps/hist/point 0.333 1.0

/gps/hist/point 1.0 0.0

The area of the spherical cap is: A=2*!PI*(1-cos(60))

How is the GF estimated then? unless I am doing something wron with the positioning biasing, I would have expected "N_detected" to be reduced by approx. A/(4*PI*R^2), but results do not seem to add up.

Thanks a lot in advance.

Note Re: non-spherical sources for estimating geometric factor  by Elias Roussos <Elias Roussos>,   20 Sep, 2017
Re: Question non-spherical sources for estimating geometric factor (Elias Roussos)
Above I mean A=2*!PI*(1-cos(60))*R^2

Question how can i use geant4 outcome to draw the dose-depth figure of mars soil.  by zhiyi han <zhiyi han>,   17 Sep, 2017
how I draw dose-depth profile in soil:

1. fitting the GCR spectra from 2Gev-100Gev, i get y1=x*10^((0.18*(log10(x))^3)-(2.6*(log10(x))^2)+9.8*(log10(x))-11);y1(particles/m2-s-sr-MeV/nuc) ;   x(MeV/nuc)


2,cut GCR spectra into 3 sections: 1-10Gev, 10-100Gev, 100-1000Gev.  
Take samples (for every sample, beam on 1000) from each section and run the simulation and get the dose data.  
(total soil depth is 2m, score mesh is 40,so dose is recorded every 5cm in soil)


3,in first soil layer(0-5cm),plot the Dose-Energy image for three sections. Fitting them. y(Gy); x(Mev),i get

1-10Gev		y2=(-(3.5*10^-32)*x^4+(7.8*10^-28)*x^3-(5.5*10^-24)*x^2+(1.6*10^-20)*x-1.5*10^-17);

10-100Gev 		y3=(-(3.1*10^-40)*x^5+(7.2*10^-35)*x^4-(5.5*10^-30)*x^3+(1.4*10^-25)*x^2+(2.3*10^-21)*x-1*10^-17);

100-1000Gev   y4=((1.8*10^-33)*x^3-(3.4*10^-27)*x^2+(1.8*10^-21)*x+3.6*10^-17);


4,dose that is produced by one particle * number of the particle = total dose.

base on my calculation, the number of particle is y1/x , dose is y2, y3, y4 for each section

so F1=(y1/x)*y2,integrate F1 from 1-10Gev,  
F2=(y1/x)*y3,  integrate F2 from 10-100Gev,
F3=(y1/x)*y4,  integrate F3 from 100-1000Gev.  sum them up, i get F4, F4=F3+F2+F1.

score box is 20m * 20m *2 m, so F4*400*(60*60*24*365)=F5, F5 is the total dose that is produced by all GCRs in this soil layer during the whole year.


but the outcome i get is about 10e-7 smaller than the reference. what is wrong? any help? THANKS for your attention and help in advance.



*****************************************************************

details:


Geant4 simulation of  radiation in Mars atmosphere and soil

version
GEANT4.10.02.p02

application
Based on B4a, changed its geometry and physics_list, added scorerwriter in B4a Main().     (.../geant4.10.02.p02/examples/basic/B4/B4a)

physics_list  
QGSP_BERT_HP 3.0

geometry 
world       			30*m X 30*m X 140000*m  (X Y  Z)
20 layers of air.(upon soil)   		20*m X 20*m X 70000*m  (X Y  Z)
Soil layer(under the air layers) 			20*m X 20*m X 20*m (X Y  Z)

primary generator(particle gun)
particle:proton
position(0, 0, -70000*m) (X Y  Z)
direction(0, 0, 1*m)(X Y  Z)


dose, energy deposition, secondaries data collected from run1.mac boxMesh. Scorer size is 20*m X 20*m X 2*m (X Y  Z), every layers is 5*cm along Z axies.

/score/create/boxMesh boxMesh_1
/score/mesh/boxSize 10 10 1 m
/score/mesh/nBin 1 1 40
/score/dumpQuantityToFile boxMesh_1 edep scoreenergydeposit.txt
/score/dumpQuantityToFile boxMesh_1 ndar scorenumberofsecondaries.txt
/score/dumpQuantityToFile boxMesh_1 dpo  scoredosedeposit.txt
None simplest example of reverse monte carlo for GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   25 Aug, 2017
Hello, I have a setup using gdml and gps file. How do I modify it for an adjoint simulation in GRAS? I found the simple_geo example in GRAS, but was hoping to use the gps file in the adjoint simulation, if this is possible. Best regards, Sveta

None Re: simplest example of reverse monte carlo for GRAS  by Tevfik Kaplanoglu <Tevfik Kaplanoglu>,   25 Aug, 2017
Re: None simplest example of reverse monte carlo for GRAS (Svetlana Shasharina)
​​
​​
​​
​​
Hi ​
​​
Svetlana,

Unfortunanately you can't run this macro simultaneously with adjoint mode,
also there is no source position definition in your macro file. However, i
can recommend using integral data with adjoint mode instead of using
differential data.

After translating to fluence, the data should look as exponential and you
can apply the data with following functions :

/adjoint_physics/SetEminForAdjointModels
/adjoint_physics/SetEmaxForAdjointModels

If the data is not exponential you can divide (if possible) each
exponential range to a new run via adding a loop to macro.

In the adjoint mode, the events will be biased on a sphere, target material
or sensitive detector, so omnidirectional behaivour will change.

There is good example in examples directory
(examples/extended/biasing/ReverseMC01) and its comparing both forward(with
gps) and reverse mc method.

Best,
Tevfik


On 25 August 2017 at 19:47, Svetlana G. Shasharina <sveta@txcorp.com> wrote:

> Hi Tevfik,
>
> I have a user-defined source: differential fluence vs energy.  It is
> ​​
> omnidirectional (I attach a gps file).  I would like to run adjoint
> simulation which corresponds to a direct simulation with this gps).
>
> Thank you,
>
> ​​
> Svetlana
>
>
> On 8/25/17 12:26 PM, M.Tevfik Kaplanoglu wrote:
>
> ​​
> ​​
> ​​
> ​​
> ​​
> ​​
>
> Dear Svetlana,
>
> Using GPS with Adjoint is not avaible at the moment
> ​, ​the adjoint/rmc code has some abilities for particle generating
> similar like GPS. What do you expect to create as radiation source?
>
> greetings,
> Tevfik
> On 25/08/2017 8:29 PM, "Svetlana Shasharina" <sveta@txcorp.com> wrote:
>
>>
>> *** Discussion title: Space Applications
>>
>> Hello, I have a setup using gdml and gps file. How do I modify it for an
>> adjoint simulation in GRAS? I found the simple_geo example in GRAS, but
>> was hoping to use the gps file in the adjoint simulation, if this is
>> possible. Best regards, Sveta
>>
>> -------------------------------------------------------------
>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or
>> unsubscribe) at:
>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/spac
>> e_app/130.html
>>
>
>


-- 
M. Tevfik Kaplanoğlu
+90 554 378 2975 <+90%20554%20378%2029%2075>

 [ MIME part of type text/html without a name stripped ]

None Re: simplest example of reverse monte carlo for GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   28 Aug, 2017
Re: None Re: simplest example of reverse monte carlo for GRAS (Tevfik Kaplanoglu)
I have looked at GRAS's examples for reverse monte carlo and it looks that I just can use the gps file data for defining the external source as follows:

/gps/ene/type Arb

/gps/hist/type arb

/gps/hist/point 1.000e-03 9.990e-01

/gps/hist/point 1.585e-03 9.984e-01

/gps/hist/point 2.512e-03 9.975e-01

/gps/hist/point 3.981e-03 9.960e-01

/gps/hist/point 6.310e-03 9.937e-01

/gps/hist/point 1.000e-02 9.900e-01

/gps/hist/point 1.585e-02 9.843e-01

/gps/hist/point 2.512e-02 9.752e-01

/gps/hist/point 3.981e-02 9.610e-01

# etc

/gras/analysis/adjoint/addUserDefinedPrimSpectrum e- 1. 1/cm2 Arb

/adjoint/DefineSphericalExtSource 0.000e+00 0.000e+00 0.000e+00 5.000e+00 cm

/adjoint/SetExtSourceEmax 1.000e+01 MeV

where the data is just differential fluence. So I could reuse the gps file from the forward simulation pretty much.

It would be great somebody familiar with GRAS adjoint commands could confirm. Thank you, Sveta

Idea Re: simplest example of reverse monte carlo for GRAS  by Leonardo Ghizoni <Leonardo Ghizoni>,   May 11, 10:22
Re: None Re: simplest example of reverse monte carlo for GRAS (Svetlana Shasharina)
Hi,

I'm not sure if you already figured this out, but here's an example of one of my past simulations using GRAS RMC. It's a trapped protons file of a SSO 800km orbit (the levels were taken from SPENVIS):

/gps/ene/type Arb
/gps/hist/type arb
/gps/hist/point   1.000000E-01   4.949600E+04
/gps/hist/point   1.500000E-01   3.489700E+04
/gps/hist/point   2.000000E-01   2.289800E+04
/gps/hist/point   3.000000E-01   1.044100E+04
/gps/hist/point   4.000000E-01   5.505700E+03
/gps/hist/point   5.000000E-01   2.978600E+03
/gps/hist/point   6.000000E-01   1.823800E+03
/gps/hist/point   7.000000E-01   1.159600E+03
/gps/hist/point   1.000000E+00   5.049900E+02
/gps/hist/point   1.500000E+00   1.599600E+02
/gps/hist/point   2.000000E+00   8.276700E+01
/gps/hist/point   3.000000E+00   3.253700E+01
/gps/hist/point   4.000000E+00   1.883800E+01
/gps/hist/point   5.000000E+00   1.211600E+01
/gps/hist/point   6.000000E+00   9.357900E+00
/gps/hist/point   7.000000E+00   7.460900E+00
/gps/hist/point   1.000000E+01   4.596300E+00
/gps/hist/point   1.500000E+01   2.429900E+00
/gps/hist/point   2.000000E+01   1.706700E+00
/gps/hist/point   3.000000E+01   1.148200E+00
/gps/hist/point   4.000000E+01   9.444400E-01
/gps/hist/point   5.000000E+01   8.249200E-01
/gps/hist/point   6.000000E+01   7.412400E-01
/gps/hist/point   7.000000E+01   6.907000E-01
/gps/hist/point   1.000000E+02   5.362600E-01
/gps/hist/point   1.500000E+02   3.412200E-01
/gps/hist/point   2.000000E+02   2.116100E-01
/gps/hist/point   3.000000E+02   8.763900E-02
/gps/hist/point   4.000000E+02   7.265500E-03

/gras/analysis/adjoint/addUserDefinedPrimSpectrum proton 1.091733E+12 1/cm2 Arb
#
#Definition of the adjoint source
##################################
/adjoint/DefineAdjSourceOnExtSurfaceOfAVolume {TargetName}
/adjoint/SetAdjSourceEmin 1.0000e-03 MeV
/adjoint/SetAdjSourceEmax 4.0000e+02 MeV
#
#Definition of the external source
###################################
/adjoint/DefineSphericalExtSource 0 0 0 20 cm            #<X Y Z R length_unit>
/adjoint/SetExtSourceEmax  4.0000e+02 MeV

Observe that I set the SetAdjSourceEmin and SetAdjSourceEmax as the minimum and maximum energies provided by the SPENVIS histogram.

Hope it helps.

Regards,
Leonardo.
None Re: simplest example of reverse monte carlo for GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   May 11, 10:28
Re: Idea Re: simplest example of reverse monte carlo for GRAS (Leonardo Ghizoni)
Thank you, Leonardo!  Yes, I figured this out.  I appreciate your help.

Sveta


On 5/11/18 11:22 AM, Leonardo Ghizoni wrote:
> *** Discussion title: Space Applications
>
> Hi,
>
> I'm not sure if you already figured this out, but here's an example of one of my past simulations using GRAS RMC. It's a trapped protons file of a SSO 800km orbit (the levels were taken from SPENVIS):
>
> /gps/ene/type Arb
> /gps/hist/type arb
> /gps/hist/point   1.000000E-01   4.949600E+04
> /gps/hist/point   1.500000E-01   3.489700E+04
> /gps/hist/point   2.000000E-01   2.289800E+04
> /gps/hist/point   3.000000E-01   1.044100E+04
> /gps/hist/point   4.000000E-01   5.505700E+03
> /gps/hist/point   5.000000E-01   2.978600E+03
> /gps/hist/point   6.000000E-01   1.823800E+03
> /gps/hist/point   7.000000E-01   1.159600E+03
> /gps/hist/point   1.000000E+00   5.049900E+02
> /gps/hist/point   1.500000E+00   1.599600E+02
> /gps/hist/point   2.000000E+00   8.276700E+01
> /gps/hist/point   3.000000E+00   3.253700E+01
> /gps/hist/point   4.000000E+00   1.883800E+01
> /gps/hist/point   5.000000E+00   1.211600E+01
> /gps/hist/point   6.000000E+00   9.357900E+00
> /gps/hist/point   7.000000E+00   7.460900E+00
> /gps/hist/point   1.000000E+01   4.596300E+00
> /gps/hist/point   1.500000E+01   2.429900E+00
> /gps/hist/point   2.000000E+01   1.706700E+00
> /gps/hist/point   3.000000E+01   1.148200E+00
> /gps/hist/point   4.000000E+01   9.444400E-01
> /gps/hist/point   5.000000E+01   8.249200E-01
> /gps/hist/point   6.000000E+01   7.412400E-01
> /gps/hist/point   7.000000E+01   6.907000E-01
> /gps/hist/point   1.000000E+02   5.362600E-01
> /gps/hist/point   1.500000E+02   3.412200E-01
> /gps/hist/point   2.000000E+02   2.116100E-01
> /gps/hist/point   3.000000E+02   8.763900E-02
> /gps/hist/point   4.000000E+02   7.265500E-03
>
> /gras/analysis/adjoint/addUserDefinedPrimSpectrum proton 1.091733E+12 1/cm2 Arb
> #
> #Definition of the adjoint source
> ##################################
> /adjoint/DefineAdjSourceOnExtSurfaceOfAVolume {TargetName}
> /adjoint/SetAdjSourceEmin 1.0000e-03 MeV
> /adjoint/SetAdjSourceEmax 4.0000e+02 MeV
> #
> #Definition of the external source
> ###################################
> /adjoint/DefineSphericalExtSource 0 0 0 20 cm            #<X Y Z R length_unit>
> /adjoint/SetExtSourceEmax  4.0000e+02 MeV
>
> Observe that I set the SetAdjSourceEmin and SetAdjSourceEmax as the minimum and maximum energies provided by the SPENVIS histogram.
>
> Hope it helps.
>
> Regards,
> Leonardo.
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/130/1/1/1.html
>

-- 
Svetlana Shasharina                            | sveta@txcorp.com
Vice-President of Computational Infrastructure | Tech-X Corporation
Question capture high precision neutron  by jacques <jacques>,   23 Aug, 2017
hello, im working on measuring nbr of hits collected by few crystals located in a box, till now im able to record the total nbr of hits including the scattered ones...but i need to measure just the captured neutrons by each crystal. any suggestion how to add it? thanks in advance

Idea Re: capture high precision neutron  by Leonardo Ghizoni <Leonardo Ghizoni>,   May 11, 10:42
Re: Question capture high precision neutron (jacques)
Hi,

Not sure if you figured this out, but my guess to detect specifically the neutrons would be:

/gras/analysis/fluence/addModule "Module_Name"
/gras/analysis/fluence/Module_Name/addVolumeInterface Vol1 Vol2
/gras/analysis/fluence/Module_Name/insertParticle neutron
/gras/analysis/fluence/Module_Name/initialise

Also, I would add a hadronic physics library, like FTFP_BERT (I usually use em_standard_opt3 + FTFP_BERT in my simulations).

Hope it helps.

Regards,
Leonardo.
Question a question about gps/pos for gaussian beam geometry  by <Claire>,   10 May, 2017
Hello I have a question about : gps/pos/ I would like to model a monochromatic beam with a Gaussian geometry (Gaussian symmetric shape in a XY plane perpendicular to the direction of propagation Z). The FWHM is the same in both directions X and Y, of 1 micrometer. So sigma = 1/2.355 =0.4246 micrometers. The beam is purely Gaussian, there is no central circular plateau.

Example 31 of the Gant4 toolkit is very close to what I would like to do:

# the beam spot is centered at the origin and is

# of 1d gaussian shape with a 1 mm central plateau

/gps/pos/shape Circle

/gps/pos/centre 0. 0. 0. mm

# Should I comment this line? /gps/pos/radius 1. mm

/gps/pos/sigma_r .4246 um

So my question is: Should I comment the line with radius, since our beam does not have a central plateau? Or should I take a radius with a very small value compared to sigma_r ? (otherwise we would define a circle shape without radius, which would maybe be not possible ?)Or is there another shape than "circle" for a pure Gaussian shape ? Thank you

Question GRAS returns error when using Heavy Ions primaries on composite shieldings  by Leonardo Ghizoni <Leonardo Ghizoni>,   30 Apr, 2017
Hello,

I'm simulating different mixtures for shielding materials, and I've got the following error when shooting Au197 ions:

-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : had006
      issued by : G4HadronicProcess::PostStepDoIt
In /home/lghizoni/Geant4/geant4.10.01/source/processes/hadronic/util/src/G4HadSecondary.cc, line 36: 
===> ATTEMPTING TO CREATE A SECONDARY WITH NEGATIVE KINETIC ENERGY.
Call for Binary Light Ion Cascade
Target element Re  Z= 75  A= 187
Unrecoverable error in the method ApplyYourself of ionInelastic
TrackID= 1  ParentID= 0  Au197
Ekin(GeV)= 10.2981;  direction= (0.00233913,-0.00273888,-0.999994)
Position(mm)= (3.05801,-13.2243,11.7177);  material NanoShield4
PhysicalVolume  <Shield4>
 ApplyYourself failed

*** Fatal Exception *** core dump *** -------- EEEE -------- G4Exception-END --------- EEEE -------

*** G4Exception: Aborting execution *** Aborted (core dumped)

I'm using GRAS 3.4 with GEANT4 10.01 patch3. The shielding material contains the following elements: Cr, Fe, Re and B.

Do anyone know know how to solve this?

Thanks in advance.

Leonardo.

Question Re: GRAS returns error when using Heavy Ions primaries on composite shieldings  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   01 May, 2017
Re: Question GRAS returns error when using Heavy Ions primaries on composite shieldings (Leonardo Ghizoni)
Hello,

what Physics List do you use?

VI

Ok Re: GRAS returns error when using Heavy Ions primaries on composite shieldings  by Leonardo Ghizoni <Leonardo Ghizoni>,   01 May, 2017
Re: Question Re: GRAS returns error when using Heavy Ions primaries on composite shieldings (Vladimir Ivanchenko)
Thanks a lot for the answer.

I'm using Em_standard_Opt3 + FTFP_BERT

I actually ran the code again and it showed no errors, but I thought it would be a good idea to report the previous error.

Regards, Leonardo.

Question Understanding GRAS RMC Results  by Leonardo Ghizoni <Leonardo Ghizoni>,   20 Sep, 2016
Hi experts,

I'm having simulations on GRAS for a space system and I'm applying the RMC method. I'm a little confused about the results. I ask the simulation to calculate the total on a given device of my system:

/gras/analysis/dose/addModule TID_{TargetName}

/gras/analysis/dose/TID_{TargetName}/bookTuples false

/gras/analysis/dose/TID_{TargetName}/addVolume *{TargetName}*

/gras/analysis/dose/TID_{TargetName}/setUnit rad

/gras/analysis/dose/TID_{TargetName}/initialise

Then I get two different histograms:

TID Dose TID total dose vs primary kine

Summing the results of the second histogram, I should get the same value of dose as the first one, right? But they are very different. At the same time, the dose value of the first histogram gives extremely high numbers. Am I missing something here?

Thanks in advance.

None Different ionic states of elements for materials  by <MWestphal>,   02 Sep, 2016
Hello,

Is there a way to create materials out of elements in different ionic states (i.e. Fe +2, Fe +3, etc.) in Geant4?

Thanks in advance.

Question How to use and normalise an energy spectrum as input  by Germn Ros <Germn Ros>,   27 Jul, 2016
Hello!

I am trying to use an energy spectrum as an input and I have seen the example called "radioprotection" in the G4 advanced examples where this is done using the configuration file "primary.mac". Unfortunately I have several problems and things I do not really understand and I have not found the answer in Geant4 forum or elsewhere.

I would be very grateful if someone could help me.

I have the differential and integral spectrum of galactic cosmic rays obtained from SPENVIS. I have found an excel file that is used by several people in this forum to create the G4 configuration file given an energy spectrum, exactly what I need.

http://geant4.esa.int/tl_files/geant4/resources/CREME_M1_GCR_Flux_Spectra.xlt

Using it, I have created my configuration file that it is attached (GCRs_Carbon.mac). But I have several problems:

1) Following the .xls file, in the .mac file I have defined two histograms, one with the differential spectrum and a second one with the probabilities and weights for each energy. However in primary.mac only the first histo is defined, so is the second one really needed?

2) Again, following the .xls file, I have calculated a normalization factor (at the end of GCRs_Carbon.mac). However, again in primary.mac a normalization factor is not used. I think it is needed since I have to simulate several nuclei and compare the different components, but am I correct or this factor is not needed?

3) Why in the .xls file the normalization factor has /cm2/s as units but when translated to G4 code is set as cm2?

4) When trying to run geant4 with my GCRs_Carbon.mac the line /analysis/normalise 7.305E+08 give me a core dump with no other information. Do you know what am I doing wrong?

5) A more general question. When you use a spectrum as input, how are particles simulated in time? I mean, all of them are thrown at the same time, uniformly in a time interval that should be defined (how?) or something else?

Thank you very much in advanced

Best Regards,

Germn Ros

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/27/09.02-52585-GCRs_Carbon.mac

None Re: How to use and normalise an energy spectrum as input  by Germn Ros <Germn Ros>,   07 Sep, 2016
Re: Question How to use and normalise an energy spectrum as input (Germn Ros)
Thanks iSveta but I need a more specific answer to my questions.

Could someone help?

Germn

Question Re: How to use and normalise an energy spectrum as input  by panda <panda>,   22 Jan, 2018
Re: None Re: How to use and normalise an energy spectrum as input (Germn Ros)
dear Germn,

Do you solve the problems? I have the same problems with you now.

Panda

None Re: How to use and normalise an energy spectrum as input  by Svetlana Shasharina <Svetlana Shasharina>,   28 Jul, 2016
Re: Question How to use and normalise an energy spectrum as input (Germn Ros)
Hi German,
I think if you used Spenvis, you should run Gras (with a gps file for the source).  It works in conjunction of other norm factors, which are specific for Gras.  I might be wrong...

iSveta

> On Jul 27, 2016, at 10:07 AM, Germán Ros <german.ros@uah.es> wrote:
> 
> 
> *** Discussion title: Space Applications
> 
> Hello!
> 
> I am trying to use an energy spectrum as an input and I have seen the
> example called "radioprotection" in the G4 advanced examples where this
> is done using the configuration file "primary.mac". Unfortunately I have
> several problems and things I do not really understand and I have not
> found the answer in Geant4 forum or elsewhere.
> 
> I would be very grateful if someone could help me.
> 
> I have the differential and integral spectrum of galactic cosmic rays
> obtained from SPENVIS. I have found an excel file that is used by
> several people in this forum to create the G4 configuration file given
> an energy spectrum, exactly what I need.
> 
> http://geant4.esa.int/tl_files/geant4/resources/CREME_M1_GCR_Flux_Spectra.xlt
> 
> Using it, I have created my configuration file that it is attached
> (GCRs_Carbon.mac). But I have several problems:
> 
> 1) Following the .xls file, in the .mac file I have defined two
> histograms, one with the differential spectrum and a second one with the
> probabilities and weights for each energy. However in primary.mac only
> the first histo is defined, so ¿is the second one really needed?
> 
> 2) Again, following the .xls file, I have calculated a normalization
> factor (at the end of GCRs_Carbon.mac). However, again in primary.mac a
> normalization factor is not used. I think it is needed since I have to
> simulate several nuclei and compare the different components, but ¿am I
> correct or this factor is not needed?
> 
> 3) Why in the .xls file the normalization factor has /cm2/s as units but
> when translated to G4 code is set as cm2?
> 
> 4) When trying to run geant4 with my GCRs_Carbon.mac the line
> /analysis/normalise 7.305E+08 give me a core dump with no other
> information. ¿Do you know what am I doing wrong?
> 
> 5) A more general question. When you use a spectrum as input, how are
> particles simulated in time? I mean, all of them are thrown at the same
> time, uniformly in a time interval that should be defined (how?) or
> something else?
> 
> Thank you very much in advanced
> 
> Best Regards,
> 
> Germán Ros
> 
>   Attachment:
>      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/27/09.02-52585-GCRs_Carbon.mac
> 
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at: 
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/124.html 
> 
Question Isotropic flux with Planetocosmics: GPS comands not working properly   by Michael Milde <Michael Milde>,   12 Jul, 2016
Hello everyone,

I need to generate an isotropic particle flux on Earths surface through the Planetocosmics framework. For the source geometry I use the following Geant4 /gps commands:

/gps/pos/type Surface

/gps/pos/shape Sphere

/gps/pos/centre 0. 0. 0. km

/gps/pos/radius 7870 km

/gps/ang/type cos

/gps/ang/mintheta 0.00 deg

/gps/ang/maxtheta 90.00 deg

The expected flux from the starting positions on the source sphere, as Ive read in many threads here, should have a cos modulation centred around the perpendicular direction at the source sphere (and thus directed to the Earth's centre, since my source sphere is centred in 0 0 0 in a planetocentric coordinate frame).

Now my problem: if I run the simulation, the particles are correctly generated from the source sphere centred around the Earth, but their direction is centred towards a point somewhere in space, and not at the Earth's centre, as I would like. In the attachments you can find pictures (1-2) of the tracks. In picture 3 and 4 you can see the result if I set /gps/ang/mintheta 0.00 deg and /gps/ang/maxtheta 0.00 deg, so just the (expected) "zenith" direction is allowed. Here, all the tracks are pointed towards some point in space.

I already tried to add commands like /gps/ang/surfnorm, /gps/ang/user_coor, but nothing seems to help. Also the circle source has the same behaviour.

Did someone encounter this or a similar problem already and was able to solve it? Do you have some advices?

Thanks! Best Regards,

Michael

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-42312-PCSimulationSphere1.png
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-7371-PCSimulationSphere2.png
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-56069-PCSimulationSphere3.png
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-7442-PCSimulationSphere4.png

None Re: Isotropic flux with Planetocosmics: GPS comands not working properly   by Svetlana Shasharina <Svetlana Shasharina>,   12 Jul, 2016
Re: Question Isotropic flux with Planetocosmics: GPS comands not working properly (Michael Milde)
Hi Michael,
I used similar commands many times and they worked for me.  Are you sure 
you placed Earth in the same center?
Best regards,
Sveta

On 7/12/16 4:36 AM, Michael Milde wrote:
>
> *** Discussion title: Space Applications
>
> Hello everyone,
>
> I need to generate an isotropic particle flux on Earths surface through
> the Planetocosmics framework. For the source geometry I use the
> following Geant4 /gps commands:
>
> /gps/pos/type Surface
>
> /gps/pos/shape Sphere
>
> /gps/pos/centre 0. 0. 0. km
>
> /gps/pos/radius 7870 km
>
> /gps/ang/type cos
>
> /gps/ang/mintheta 0.00 deg
>
> /gps/ang/maxtheta 90.00 deg
>
> The expected flux from the starting positions on the source sphere, as
> Ive read in many threads here, should have a cos modulation centred
> around the perpendicular direction at the source sphere (and thus
> directed to the Earth's centre, since my source sphere is centred in 0 0
> 0 in a planetocentric coordinate frame).
>
> Now my problem: if I run the simulation, the particles are correctly
> generated from the source sphere centred around the Earth, but their
> direction is centred towards a point somewhere in space, and not at the
> Earth's centre, as I would like. In the attachments you can find
> pictures (1-2) of the tracks. In picture 3 and 4 you can see the result
> if I set /gps/ang/mintheta 0.00 deg and /gps/ang/maxtheta 0.00 deg, so
> just the (expected) "zenith" direction is allowed. Here, all the tracks
> are pointed towards some point in space.
>
> I already tried to add commands like /gps/ang/surfnorm,
> /gps/ang/user_coor, but nothing seems to help. Also the circle source
> has the same behaviour.
>
> Did someone encounter this or a similar problem already and was able to
> solve it? Do you have some advices?
>
> Thanks! Best Regards,
>
> Michael
>
>    Attachment:
>       http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-42312-PCSimulationSphere1.png
>       http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-7371-PCSimulationSphere2.png
>       http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-56069-PCSimulationSphere3.png
>       http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/07/12/03.34-7442-PCSimulationSphere4.png
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/123.html
>

Question Re: Isotropic flux with Planetocosmics: GPS comands not working properly   by Michael Milde <Michael Milde>,   12 Jul, 2016
Re: None Re: Isotropic flux with Planetocosmics: GPS comands not working properly (Svetlana Shasharina)
Hi Svetlana,

thank you for your answer! Yes, I am sure that the Earth is placed in the same centre. This is shown by the fact that the source surface is indeed placed correctly around the Earth (with the centre coordinates 0,0,0). Did you use the commands also in Planetocosmics or only directly in Geant4? Something wrong must happen when the direction of the cos modulated sources is set by Planetocosmics/Geant4.

Best regards, Michael

None Re: Isotropic flux with Planetocosmics: GPS comands not working properly   by Svetlana Shasharina <Svetlana Shasharina>,   12 Jul, 2016
Re: Question Re: Isotropic flux with Planetocosmics: GPS comands not working properly (Michael Milde)
Hi Michael,
I used these commands in GRAS.
Best,
Sveta

On 7/12/16 7:17 AM, Michael Milde wrote:
>
> *** Discussion title: Space Applications
>
> Hi Svetlana,
>
> thank you for your answer! Yes, I am sure that the Earth is placed in
> the same centre. This is shown by the fact that the source surface is
> indeed placed correctly around the Earth (with the centre coordinates
> 0,0,0). Did you use the commands also in Planetocosmics or only directly
> in Geant4? Something wrong must happen when the direction of the cos
> modulated sources is set by Planetocosmics/Geant4.
>
> Best regards, Michael
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/123/1/1.html
>

Question GRAS license  by Svetlana Shasharina <Svetlana Shasharina>,   23 May, 2016
I have been using GRAS for a while now and have been very happy with this application. Some files of GRAS refer to G4 license, but some state that the implementation is the intellectual property of ESA. What do these statements mean for the GRAS be distribution? Best regards, Sveta

None Re: GRAS license  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   25 Jul, 2016
Re: Question GRAS license (Svetlana Shasharina)
Hello,

GRAS is a free academic software developed by ESA. We have a problem that in the distribution different files have different licenses. We will address this in future. 

Worse to note, that for developers it is important if users include a reference to the GRAS paper into their publications.

VI
None Re: GRAS license  by Svetlana Shasharina <Svetlana Shasharina>,   25 Jul, 2016
Re: None Re: GRAS license (Vladimir Ivanchenko)
Thank you, Vladimir!  Can we use GRAS in a commercial product given that 
we will give a proper reference?
Sveta

On 7/25/16 11:19 AM, Vladimir Ivanchenko wrote:
>
> *** Discussion title: Space Applications
>
> Hello,
>
> GRAS is a free academic software developed by ESA. We have a problem that in the distribution different files have different licenses. We will address this in future.
>
> Worse to note, that for developers it is important if users include a reference to the GRAS paper into their publications.
>
> VI
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/122/1.html
>

None Re: GRAS license  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   25 Jul, 2016
Re: None Re: GRAS license (Svetlana Shasharina)
Geant4 license was designed and officially approved in order to allow commercial use of Geant4. There is no similar specific license for GRAS, there are disclaimers inside the code and general approach of ESA for free software distribution.

VI

Question Getting SSAT tool  by Leonardo Ghizoni <Leonardo Ghizoni>,   27 Mar, 2016
Hello,

I'm trying to get a local copy of SSAT tool, but I'm unable to find the proper place to get it.

I've been using the tool from SPENVIS, but I know it has some limitations regarding the processing and geometry.

Thank you in advance. Leonardo.

Question Unexpected results for fluence and TID using Spenvis/GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   08 Mar, 2016
I did the following calculations using Spenvis/GRAS(gdml):

1. Independent runs for two vacuum spheres with r = 19cm and r = 15 cm. Source: Monoenergetic (100MeV) electrons with fluence 100 (1/cm^2 s), sphere with r = 20cm.

SPENVIS calculated fluences 28390 and 17644 for the first and the second spheres. The ratio of fluences/surface_area is constant for these cases (6.24 and 6.26) and is very close to 2pi :-) but is very different from the incident fluence (100).

First confusion: I thought the calculated fluence is normalized to the target's areas. But looks like it is not. Second confusion: after dividing by the surface areas I still have a number very different to the incident environment number (100).

Maybe I do not understand what the incident fluence really mean? How do I get a number that would relate to it?

2. Ta sphere r = 15cm, calculating TID in MeV with the source described. I get 1.6564e+06MeV/s.

If all e were to absorb, I would expect 100(1/cm^2 s)*100MeV*SurfaceArea = 1e+4 MeV/s *2826cm^2 = 2.8e+7 MeV/s.

So about 1/16 of the electrons gets absorbed, I guess? If I change normalization to CURRENT instead of FLUX, I will get 1/4 difference, I assume. Still a big difference. Any intuitive reaction to this difference?

Best regards, Sveta

More Re: Unexpected results for fluence and TID using Spenvis/GRAS  by Roger Byrd <Roger Byrd>,   02 Apr, 2016
Re: Question Unexpected results for fluence and TID using Spenvis/GRAS (Svetlana Shasharina)
I have tested a normalization approach that seems to help with the various GRANT-based MULASSIS and GRAS routines.

In many space applications with omnidirectional or plane-parallel sources, the generated fluence is uniform throughout the problem geometry in the absence of particle interactions -- that is, with virtual geantinos or with the VOID entry used in the MCNP program.

For SPENVIS, the equivalent approach replaces the shielding materials with Vacuum and then analyzes (tallies) the resulting fluences throughout the geometry, whether using MULASSIS, GRAS/MULASSIS, or GRAS/GDML. One often finds that a generating source that was expected to produce a unit fluence in fact produces two or four times that result. One can then either renormalize the doses by the observed factor or adjust the input source fluence to produce an observed result of unity.

This approach has worked with both MULASSIS and GRAS, using parallel beams or omnidirectional sources, with both slab and shell shielding.

None Re: Unexpected results for fluence and TID using Spenvis/GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   09 Apr, 2016
Re: More Re: Unexpected results for fluence and TID using Spenvis/GRAS (Roger Byrd)
This line in GRAS is important:

/gras/analysis/setSourceFluenceType CURRENT/FLUX

Spenvis defaults it to

/gras/analysis/setSourceFluenceType FLUX.

GRAS results in FLUX are 4 times larger than in CURRENT (both for TID 
and fluece).

Using CURRENT gives TID consistent with G4, but the fluence is still 4 
times lower than the one that I expect from comparing with integral 
fluence given as input for simulation.

Using FLUX results in TID 4 times smaller than from G4 and in fluence 16 
smaller than expected.

Sveta


On 4/2/16 10:03 AM, Roger Byrd wrote:
>
> *** Discussion title: Space Applications
>
> I have tested a normalization approach that seems to help with the
> various GRANT-based MULASSIS and GRAS routines.
>
> In many space applications with omnidirectional or plane-parallel
> sources, the generated fluence is uniform throughout the problem
> geometry in the absence of particle interactions -- that is, with
> virtual geantinos or with the VOID entry used in the MCNP program.
>
> For SPENVIS, the equivalent approach replaces the shielding materials
> with Vacuum and then analyzes (tallies) the resulting fluences
> throughout the geometry, whether using MULASSIS, GRAS/MULASSIS, or
> GRAS/GDML. One often finds that a generating source that was expected to
> produce a unit fluence in fact produces two or four times that result.
> One can then either renormalize the doses by the observed factor or
> adjust the input source fluence to produce an observed result of unity.
>
> This approach has worked with both MULASSIS and GRAS, using parallel
> beams or omnidirectional sources, with both slab and shell shielding.
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/120/2.html
>

None Re: Unexpected results for fluence and TID using Spenvis/GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   08 Mar, 2016
Re: Question Unexpected results for fluence and TID using Spenvis/GRAS (Svetlana Shasharina)
One more data point, when I switch from FLUX to CURRENT normalization, 
the TID becomes 4 times larger, while fluences become 4 times
smaller.

Sveta

On 3/8/16 11:07 AM, Svetlana Shasharina wrote:
> *** Discussion title: Space Applications
>
> I did the following calculations using Spenvis/GRAS(gdml):
>
> 1. Independent runs for two vacuum spheres with r = 19cm and r = 15 cm.
> Source: Monoenergetic (100MeV) electrons with fluence 100 (1/cm^2 s),
> sphere with r = 20cm.
>
> SPENVIS calculated fluences 28390 and 17644 for the first and the second
> spheres. The ratio of fluences/surface_area is constant for these cases
> (6.24 and 6.26) and is very close to 2pi :-) but is very different from
> the incident fluence (100).
>
> First confusion: I thought the calculated fluence is normalized to the
> target's areas. But looks like it is not. Second confusion: after
> dividing by the surface areas I still have a number very different to
> the incident environment number (100).
>
> Maybe I do not understand what the incident fluence really mean? How do
> I get a number that would relate to it?
>
> 2. Ta sphere r = 15cm, calculating TID in MeV with the source described.
> I get 1.6564e+06MeV/s.
>
> If all e were to absorb, I would expect 100(1/cm^2 s)*100MeV*SurfaceArea
> = 1e+4 MeV/s *2826cm^2 = 2.8e+7 MeV/s.
>
> So about 1/16 of the electrons gets absorbed, I guess? If I change
> normalization to CURRENT instead of FLUX, I will get 1/4 difference, I
> assume. Still a big difference. Any intuitive reaction to this
> difference?
>
> Best regards, Sveta
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/120.html
>
None Re: Unexpected results for fluence and TID using Spenvis/GRAS  by Svetlana Shasharina <Svetlana Shasharina>,   10 Mar, 2016
Re: None Re: Unexpected results for fluence and TID using Spenvis/GRAS (Svetlana Shasharina)
I ran the same example with higher fluences and the conclusion remains: in order to get the incident fluence (1/cm^2 s), I need to divide the result of GRAS/Spenvis by 2pi and multiply to 100.

I would like to have a similar simple case where I calculate TID analytically to compare TID to the calculated TID. Does anybody have a suggestion for a case when all incident particles energy would be absorbed? Or maybe there is a classic case which everybody trusts?

Thanks, Sveta

None Changing initial seed in GRAS  by Leonardo Ghizoni <Leonardo Ghizoni>,   07 Mar, 2016
Hello,

I wander what is the best way of changing the initial seed in GRAS.

I see that I could add in the main file (assuming I'm using GRAS as an external application):

#include "Randomize.hh"
#include "time.h"

CLHEP::HepRandom::setTheEngine(new CLHEP::RanecuEngine());

G4long seed = time(NULL);

CLHEP::HepRandom::setTheSeed(seed);

But I would like to know if there's a way of changing this via macro, as that's the GRAS "way".

My initial seed is always the same:

Initial seed = 9876
 u[] = 0.174685 0.883674 0.958512 0.690013 0.0250537 0.142294 0.783649 0.356081

0.214774 0.69287 0.700302 0.465109 0.22215 0.768752 0.461089 0.397602 0.522215

0.121546 0.960227 0.510892 0.0116568 0.0286447 0.238777 0.585219 0.780612

0.709182 0.082106 0.828601 0.61446 0.0798209 0.688002 0.00978529 0.370831

0.376435 0.710184 0.864017 0.167338 0.21114 0.349235 0.522479 0.943713

0.0702708 0.778742 0.639458 0.506555 0.151751 0.990123 0.564688 0.430497

0.889832 0.995398 0.725368 0.710512 0.0550886 0.0540335 0.0159176 0.728379

0.947141 0.34922 0.20551 0.351029 0.672539 0.118976 0.655784 0.195375 0.0380308

0.293556 0.237497 0.79723 0.158375 0.029761 0.602215 0.616657 0.995638 0.734827

0.943425 0.130007 0.277064 0.306344 0.973337 0.183926 0.547536 0.914344

0.666572 0.210074 0.300351 0.83602 0.267525 0.248549 0.533332 0.1754 0.299529

0.538308 0.555472 0.283894 0.485254 0.222273

c = 0.0216029, cd = 0.456233, cm = 1

i97 = 96, u[i97] = 0.222273

j97 = 32, u[j97] = 0.370831

As a consequence, I always get exactly the same results.

Thank a lot. Leonardo.

None Re: Changing initial seed in GRAS  by Hugh Evans <Hugh Evans>,   07 Mar, 2016
Re: None Changing initial seed in GRAS (Leonardo Ghizoni)
From the GRAS manual:

Distributed parallel computing

Distributed parallel computing can be obtained by launching parallel runs on different machines. Correlations between the jobs should be avoided by forcing each job to start from different initial random seeds.

The initial seeds can be input into Geant4 via a text file. In the case of GRAS the random generator used is the Ranecu Engine, which only needs two long integers for the engine initialisation. An example random seed file content for the Ranecu Engine is the following:

0
1632641235     2127009234

The user has to provide a set of files for the job initialisation, one for each job, and insure the given seeds lead to uncorrelated simulation events. The file is then loaded into Geant4 with the UI Command:/random/resetEngineFrom

Script example:
/random/resetEngineFrom seeds.rndm

A second option is provided in GRAS to reset the random number generator. This implementation is based on the random seed generation in the cosmic ray charging Geant4 advanced example 11. In this case the random seeds are automatically internally generated at the beginning of each run based on the system clock. This option can be selected with the GRAS UI Command:

/gras/analysis/autoSeed.

Script example:

/gras/analysis/autoSeed [true | false]

The advantage of this option is that, by specifying /gras/analysis/autoSeed true, the user does not need to provide to each job the file with the couple of random seeds for the engine initialisation. However, it is important to notice that the level of correlation of the runs is in this case not under the control of the user, and should be verified case by case.

The seeds are by default automatically appended to the analysis output filename. This feature may be disabled with the UI command

/gras/analysis/seedsInFileName:

/gras/analysis/seedsInFileName [true | false]

None Re: Changing initial seed in GRAS  by Leonardo Ghizoni <Leonardo Ghizoni>,   07 Mar, 2016
Re: None Re: Changing initial seed in GRAS (Hugh Evans)
Thanks a lot for the answer.

As I'm using GRAS as an external application, I'm adding custom commands on my main code, like the physics models for example:

UImanager->ApplyCommand("/gras/physics/addPhysics em_livermore");

For the autoSeed command, should I add before or after the GRASRunManager initialization?

I ask because I had to add the physics models before the RunManager initialization. Some other processes like fluorescence, on the other hand, I had to add after the initialization for it to work.

runManager->Initialize();

UImanager->ApplyCommand("/process/em/fluo true");

UImanager->ApplyCommand("/process/em/auger true");

UImanager->ApplyCommand("/process/em/pixe true");

Thanks again.

Question Non-Ionizing energy loss (NIEL)  by aimsphere <aimsphere>,   05 Feb, 2016
Hello G4 developers and users,

I would like to estimate displacement damage (DD) in a silicon detector in space. I understand that it is calculated as a product of the Non-Ionizing energy loss (NIEL) and the particle fluence. My question here is about NIEL calculation.

I found that there is a method called GetNonIonizingEnergyDeposit() which can be accessed from the G4step class. Is this method appropriate to estimate NIEL and thus the DD dose? Has anyone tried it?

Thank you.

None Re: Non-Ionizing energy loss (NIEL)  by Hugh Evans <Hugh Evans>,   11 Feb, 2016
Re: Question Non-Ionizing energy loss (NIEL) (aimsphere)
On Fri, 05 Feb 2016 13:34:07 GMT, aimsphere wrote:
> Hello G4 developers and users,
> 
> I would like to estimate displacement damage (DD) in a silicon detector
> in space. I understand that it is calculated as a product of the
> Non-Ionizing energy loss (NIEL) and the particle fluence. My question
> here is about NIEL calculation.

In Mulassis and GRAS we tend to use a method that involves the folding of the shielded environment spectrum with the NIEL curve. This produces the TNID (Total Non-Ionising Dose) at the surface between two volumes. As most TNID effects are manifested in optical components (solar cells, opto-couplers, etc) the sensitive volume is usually very thin (unlike for human effects) and this approximation works very well.

So, to achieve this, we calculate the fluence of particles crossing the surface, weighting the particles by 1/cosine of the angle of incidence. This shielded fluence spectrum is then folded with the relevant NIEL curve.

> 
> I found that there is a method called GetNonIonizingEnergyDeposit()
> which can be accessed from the G4step class. Is this method appropriate
> to estimate NIEL and thus the DD dose? Has anyone tried it?

Laurent Desorgher did implement such a method in Gras, which is in the v3.4 release:
    /gras/analysis/nid 

Regards, Hugh

None Re: Non-Ionizing energy loss (NIEL)  by xue <xue>,   28 Mar, 2016
Re: None Re: Non-Ionizing energy loss (NIEL) (Hugh Evans)
HI,friend ,i also do the same work with you .But I used Geant4.And I want to using mulassis,but i cannot find the software (Mulassis),bacause its (http://reat.space.qinetiq.com/mulassis/)can not open.Can you tell me ,how to downland the software?On Thu, 11 Feb 2016 08:26:16 GMT, Hugh Evans wrote:
> On Fri, 05 Feb 2016 13:34:07 GMT, aimsphere wrote:
> 
> > Hello G4 developers and users,
> > 
> > I would like to estimate displacement damage (DD) in a silicon detector
> > in space. I understand that it is calculated as a product of the
> > Non-Ionizing energy loss (NIEL) and the particle fluence. My question
> > here is about NIEL calculation.
> 
> In Mulassis and GRAS we tend to use a method that involves the folding
> of the shielded environment spectrum with the NIEL curve. This produces
> the TNID (Total Non-Ionising Dose) at the surface between two volumes.
> As most TNID effects are manifested in optical components (solar cells,
> opto-couplers, etc) the sensitive volume is usually very thin (unlike
> for human effects) and this approximation works very well.
> 
> So, to achieve this, we calculate the fluence of particles crossing the
> surface, weighting the particles by 1/cosine of the angle of incidence.
> This shielded fluence spectrum is then folded with the relevant NIEL
> curve.
> 
> > 
> > I found that there is a method called GetNonIonizingEnergyDeposit()
> > which can be accessed from the G4step class. Is this method appropriate
> > to estimate NIEL and thus the DD dose? Has anyone tried it?
> 
> Laurent Desorgher did implement such a method in Gras, which is in the v3.4 release:
>     /gras/analysis/nid 
> 
> Regards, Hugh
> 

None tessellated in gdml  by andrea lucaroni <andrea lucaroni>,   23 Dec, 2015
Dear all

i have a geometry in gdml format.
I created this geometry with Instep, the code is loaded correctly, but it
seems that the volumes are empty, when i run with gras, i'm reporting under
the line of analysis of geometry by gras.

[GRASGeometryUtil::ListLogicalVolumes]: 471 volumes in the store
   Volume <CSP_1_vol>   Material: Al   Mass: [kg] 1.62854e-12   ([kg]
1.62854e-12  including sub-tree)
   Volume <CSP_2_vol>   Material: Si   Mass: [kg] 8.45983e-13   ([kg]
8.45983e-13  including sub-tree)
   Volume <CSP_3_vol>   Material: Al   Mass: [kg] 1.16744e-14   ([kg]
1.16744e-14  including sub-tree)
   Volume <CSP_4_vol>   Material: Al   Mass: [kg] 1.1665e-14   ([kg]
1.1665e-14  including sub-tree)
   Volume <CSP_5_vol>   Material: Al   Mass: [kg] 5.7097e-14   ([kg]
5.7097e-14  including sub-tree)
   Volume <CSP_6_vol>   Material: Si   Mass: [kg] 5.25532e-13   ([kg]
5.25532e-13  including sub-tree)
   Volume <CSP_7_vol>   Material: Al   Mass: [kg] 4.4183e-14   ([kg]
4.4183e-14  including sub-tree)


for example:
mass of CSP_2_vol must be about 4e-3 kg not   8.45983e-13 kg

Are there commands from put in the gdml file to consider the solid volumes ?

thanks
best regardes
Andrea


Andrea

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None Re: tessellated in gdml  by Svetlana Shasharina <Svetlana Shasharina>,   23 Dec, 2015
Re: None tessellated in gdml (andrea lucaroni)
Can you visualize this gdml using this example from Geant4:
geant4/examples/extended/persistency/gdml/G01/load_gdml ?

If you see what is expected, maybe the materials are screwed up (densities)?
SVeta

On 12/23/15 5:58 AM, andrea lucaroni wrote:
>
> *** Discussion title: Space Applications
>
> Dear all
>
> i have a geometry in gdml format.
> I created this geometry with Instep, the code is loaded correctly, but it
> seems that the volumes are empty, when i run with gras, i'm reporting under
> the line of analysis of geometry by gras.
>
> [GRASGeometryUtil::ListLogicalVolumes]: 471 volumes in the store
>     Volume <CSP_1_vol>   Material: Al   Mass: [kg] 1.62854e-12   ([kg]
> 1.62854e-12  including sub-tree)
>     Volume <CSP_2_vol>   Material: Si   Mass: [kg] 8.45983e-13   ([kg]
> 8.45983e-13  including sub-tree)
>     Volume <CSP_3_vol>   Material: Al   Mass: [kg] 1.16744e-14   ([kg]
> 1.16744e-14  including sub-tree)
>     Volume <CSP_4_vol>   Material: Al   Mass: [kg] 1.1665e-14   ([kg]
> 1.1665e-14  including sub-tree)
>     Volume <CSP_5_vol>   Material: Al   Mass: [kg] 5.7097e-14   ([kg]
> 5.7097e-14  including sub-tree)
>     Volume <CSP_6_vol>   Material: Si   Mass: [kg] 5.25532e-13   ([kg]
> 5.25532e-13  including sub-tree)
>     Volume <CSP_7_vol>   Material: Al   Mass: [kg] 4.4183e-14   ([kg]
> 4.4183e-14  including sub-tree)
>
> for example:
> mass of CSP_2_vol must be about 4e-3 kg not   8.45983e-13 kg
>
> Are there commands from put in the gdml file to consider the solid volumes ?
>
> thanks
> best regardes
> Andrea
>
> Andrea
>
>   [ MIME part of type text/html without a name stripped ]
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/117.html
>

Question Dose-depth curves from SSAT  by Michael Harig <Michael Harig>,   15 Dec, 2015
My apologies from the beginning. I am a new user to SPENVIS/GEANT4.

I currently have Geant4 working without any problems.

I am trying to evaluate radiation transport through various shielding materials in space environments such as on the ISS and/or Mars using SSAT tool in SPENVIS.

Will someone please help point me in the right direction so that I can get the dose-depth curves plotted?

None Re: Dose-depth curves from SSAT  by Hugh Evans <Hugh Evans>,   16 Dec, 2015
Re: Question Dose-depth curves from SSAT (Michael Harig)
On Wed, 16 Dec 2015 01:50:06 GMT, Michael Harig wrote: > My apologies from the beginning. I am a new user to SPENVIS/GEANT4.

We all started somewhere!

> I am trying to evaluate radiation transport through various shielding
> materials in space environments such as on the ISS and/or Mars using
> SSAT tool in SPENVIS.

FYI, SSAT does not evaluate based on different materials, other than the simplest relative density of the material. It is a ray tracing tool, where the total shielding thickness in terms of g/cm2 is calculated for the target. If you really want to investigate the shielding effectiveness of various materials, I would point you to Mulassis (1D simulation) or GRAS (3D simulation).

> 
> Will someone please help point me in the right direction so that I can
> get the dose-depth curves plotted?

The dose-depth curves in Spenvis are obtained via the SHIELDOSE tool, found on the SPENVIS main menu as "Ionizing dose for simple geometries". From here you can create the dose-depth curve for the orbit, radiation belt and solar proton models you should previously have run. It is in SHIELDOSE where you include the shielding distribution from the SPENVIS SSAT run in order to calculate the total dose at the target in the SSAT geometry.

Regards, Hugh

None Fwd: install gras  by andrea lucaroni <andrea lucaroni>,   12 Dec, 2015
Hi,

I have just installed geant4.9.6.p04 and GRAS-03-03 on my linux computer. I
have enabled GDML, i try to run the exemple:

automatic_normalisation/

gras perevent_normalisation.g4mac


I get this error:

4GDML: Reading 'geo1D.gdml' done!

Stripping off GDML names of materials, solids and volumes ...

[PhysicsList::ConstructProcess]

unusable number for repFlag: repFlag=1071881836

In
/home/dicrescenzo/ARTE/soft/geant4.9.6.p03/source/processes/hadronic/models/neutron_hp/src/G4NeutronHPElasticFS.cc,
line 178:

===> G4NeutronHPElasticFS::Init -- unusable number for repFlag

terminate called after throwing an instance of 'G4HadronicException'

  what():  std::exception

Aborted


Thank you in advance for any help,

Andrea

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Idea Re: Fwd: install gras  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   13 Dec, 2015
Re: None Fwd: install gras (andrea lucaroni)
Hello,

it may be a run time problem and not a problem of installation. Can you try out any other test available in the distribution?

VI
None Re: Fwd: install gras  by andrea lucaroni <andrea lucaroni>,   30 Dec, 2015
Re: Idea Re: Fwd: install gras (Vladimir Ivanchenko)
Hi

thanks for replay
i try other test available but there are similar error.

Could you help me please?

best regards

Andrea

On Sun, Dec 13, 2015 at 7:06 PM, Vladimir Ivanchenko <
Vladimir.Ivantchenko@cern.ch> wrote:

>
> *** Discussion title: Space Applications
>
> Hello,
>
> it may be a run time problem and not a problem of installation. Can you
> try out any other test available in the distribution?
>
> VI
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or
> unsubscribe) at:
>
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/115/1.html
>

 [ MIME part of type text/html without a name stripped ]

None Re: Fwd: install gras  by andrea lucaroni <andrea lucaroni>,   30 Dec, 2015
Re: None Re: Fwd: install gras (andrea lucaroni)
I try to run my code i get this error:

[GRASAnalysisManager::EndOfEvent] Event# 100
                                    Total CPU time used so far: 1.67
seconds.
nb_particles
nb_particles
nb_particles
nb_particles
nb_particles
Error in <TPluginManager::FindHandler>: Cannot find plugin handler for
TVirtualStreamerInfo! Does $ROOTSYS/etc/plugins/TVirtualStreamerInfo exist?

 *** Break *** segmentation violation
Error in <TUnixSystem::StackTrace> script /etc/root/gdb-backtrace.sh is
missing
WARNING - Attempt to delete the physical volume store while geometry closed
!
WARNING - Attempt to delete the solid store while geometry closed !
WARNING - Attempt to delete the logical volume store while geometry closed !
WARNING - Attempt to delete the region store while geometry closed !


On Wed, Dec 30, 2015 at 4:10 PM, andrea lucaroni <alucaroni@gmail.com>
wrote:

> Hi
>
> thanks for replay
> i try other test available but there are similar error.
>
> Could you help me please?
>
> best regards
>
> Andrea
>
> On Sun, Dec 13, 2015 at 7:06 PM, Vladimir Ivanchenko <
> Vladimir.Ivantchenko@cern.ch> wrote:
>
>>
>> *** Discussion title: Space Applications
>>
>> Hello,
>>
>> it may be a run time problem and not a problem of installation. Can you
>> try out any other test available in the distribution?
>>
>> VI
>>
>> -------------------------------------------------------------
>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or
>> unsubscribe) at:
>>
>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/115/1.html
>>
>
>

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Idea Re: Fwd: install gras  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   04 Jan, 2016
Re: None Re: Fwd: install gras (andrea lucaroni)
Hello,

it seems that the problem is in ROOT installation. What version of ROOT do you use? What version of compiler is used? What operation system?
None Re: Fwd: install gras  by andrea lucaroni <andrea lucaroni>,   04 Jan, 2016
Re: Idea Re: Fwd: install gras (Vladimir Ivanchenko)
Dear Vladimir

thanks for replay,

the operation system is:
Linux x86_64 x86_64 x86_64 GNU/Linux
ROOT installation is:
ROOT 5.30/06 (branches/v5-30-00-patches@42572, Nov 23 2015, 09:11:00 on
linuxx8664gcc
gcc is
gcc version 4.4.7 20120313 (Red Hat 4.4.7-11) (GCC)
g++ is


thanks
Andrea


On Mon, Jan 4, 2016 at 6:05 PM, Vladimir Ivanchenko <
Vladimir.Ivantchenko@cern.ch> wrote:

>
> *** Discussion title: Space Applications
>
> Hello,
>
> it seems that the problem is in ROOT installation. What version of ROOT do
> you use? What version of compiler is used? What operation system?
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or
> unsubscribe) at:
>
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/115/1/1/1/1.html
>

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Idea Re: Fwd: install gras  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   05 Jan, 2016
Re: None Re: Fwd: install gras (andrea lucaroni)
Hello Andrea,

from my point of view compiler, GRAS and ROOT does not contradict each other. 

In truth, I am not big expert in software installation. In such circumstances I would first do a simple thing:  start from a new session, try to check that Geant4/GRAS/ROOT environment is defined according to the manual, recompile Geant4 from scratch, recompile GRAS from scratch, try the same test again.

I would first run macro tests/global/gras.in

Cheers,
Vladimir  

Question GRAS crashes for Z >= 2  by Leonardo Ghizoni <Leonardo Ghizoni>,   12 Nov, 2015
Hello,

I'm using GRAS 3.3 as external application with GEANT4.9.6.p04. I'm building a satellite for LEO mission and taking the macro files from SPENVIS as input. I use QBBC as my physics list.

The simulation runs well for trapped electrons, trapped protons and solar protons. When running with GCR Z = 1 source, I start to get some warning messages:

-------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : had012
      issued by : G4HadronicProcess:CheckResult()
Warning: Bad energy non-conservation detected, will re-sample the interaction
 Process / Model: ionInelastic / Binary Light Ion Cascade
 Primary: Li7[0.0] (1000030070), E= 15557.6, target nucleus (13,27)
 E(initial - final) = 6668.06 MeV.

*** This is just a warning message. *** -------- WWWW -------- G4Exception-END --------- WWWW -------

But the simulation ends with no further problems. When I run with GCR Z >= 2, the warning messages become very frequent, till the simulation crashes:

In /home/lghizoni/Geant4/geant4.9.6/source/processes/hadronic/models/parton_string/management/src/G4VPartonStringModel.cc, line 81: ===> G4VPartonStringModel::Scatter(): fails to generate strings

-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : had006
      issued by : G4HadronicProcess::PostStepDoIt
In /home/lghizoni/Geant4/geant4.9.6/source/processes/hadronic/models/parton_string/management/src/G4VPartonStringModel.cc, line 81:
===> G4VPartonStringModel::Scatter(): fails to generate strings
Call for FTFP
Target element H  Z= 1  A= 1
Unrecoverable error in the method ApplyYourself of ionInelastic
TrackID= 1  ParentID= 0  Li7[0.0]
Ekin(GeV)= 50.4311;  direction= (-0.30308,-0.102135,0.947476)
Position(mm)= (-59.0097,-284.055,-1586.32);  material Hydrazine
PhysicalVolume  <Fuel>
 ApplyYourself failed

*** Fatal Exception *** core dump *** -------- EEEE -------- G4Exception-END --------- EEEE -------

*** G4Exception: Aborting execution *** Aborted

I tried to change the physics list to FTFP_BERT_HP and Shielding, but the simulation still crashes.

I thank very much for help, since I cannot find a solution for the problem.

Leonardo.

None Re: GRAS crashes for Z >= 2  by Hugh Evans <Hugh Evans>,   13 Nov, 2015
Re: Question GRAS crashes for Z >= 2 (Leonardo Ghizoni)
I've heard about this problem recently. It doesn't appear to exist in G4.9.6.p02, nor in G4.10.01.

You might try using one of those versions instead.

Regards, Hugh

On Fri, 13 Nov 2015 00:58:59 GMT, Leonardo Ghizoni wrote:

> Hello,
> 
> I'm using GRAS 3.3 as external application with GEANT4.9.6.p04. I'm
> building a satellite for LEO mission and taking the macro files from
> SPENVIS as input. I use QBBC as my physics list.
> 

Idea Re: GRAS crashes for Z >= 2  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   13 Nov, 2015
Re: None Re: GRAS crashes for Z >= 2 (Hugh Evans)
Hello,

unfortunately, it is difficult to find a simple solution for this problem. It happens in FTFP model when target is light like Hydrogen. Because Geant4 has only FTFP model for ion/ion interactions at high energies the same model is used in all Physics Lists. 

If you really need high energy ion interactions, then the only way is to upgrade to the most recent GRAS gras-03-04 and Geant4 10.1p02 where this problem was fixed.

VI
Question Re: GRAS crashes for Z >= 2  by Leonardo Ghizoni <Leonardo Ghizoni>,   13 Nov, 2015
Re: Idea Re: GRAS crashes for Z >= 2 (Vladimir Ivanchenko)
Thank you very much for your help. I installed Geant4.10.01p2 successfully. When trying to install GRAS 3.4, I first set the Geant4 source libraries:

> ...geant4.10.01-install/bin/geant4.sh

And then run the configure_and_install.sh. I answered the questions the same way I did with GRAS 3.3, but then I get the following error:

CMake Error at source/CMakeLists.txt:9 (add_subdirectory):
  add_subdirectory given source "SpenvisCSV" which is not an existing
  directory.

CMake Error at source/CMakeLists.txt:10 (get_directory_property):
  get_directory_property DIRECTORY argument provided but requested directory
  not found.  This could be because the directory argument was invalid or, it
  is valid but has not been processed yet.

CMake Error at source/CMakeLists.txt:11 (get_directory_property):
  get_directory_property DIRECTORY argument provided but requested directory
  not found.  This could be because the directory argument was invalid or, it
  is valid but has not been processed yet.

-- process subdir :field_models

-- process subdir :adjoint_physics

-- GRAS will be compiled with GDML!

-- Found XercesC: /usr/lib/x86_64-linux-gnu/libxerces-c.so

-- GRAS will be compiled with meshing analysis module!

-- Found ROOT 5.34/14 in /usr!!

-- GRAS will be compiled with ROOT

-- Configuring incomplete, errors occurred!

See also "/home/lghizoni/Geant4/gras-03-04/build/CMakeFiles/CMakeOutput.log". Compilation of the code with make!

make: *** No targets specified and no makefile found. Stop. Installation of the code!

make: *** No rule to make target `install'. Stop.

I followed the same steps as when installing GRAS 3.3...nothing apparently different.

Thanks a lot!

Leonardo.

News Re: GRAS crashes for Z >= 2  by Hugh Evans <Hugh Evans>,   16 Nov, 2015
Re: Question Re: GRAS crashes for Z >= 2 (Leonardo Ghizoni)
Hi,

For some reason the SpenvisCSV package wasn't included in the tarball.

I've updated the tarball on the GRAS site and it should now include the SpenvisCSV package.

Please let me know how it goes.

Regards Hugh

Ok Re: GRAS crashes for Z >= 2  by Leonardo Ghizoni <Leonardo Ghizoni>,   16 Nov, 2015
Re: News Re: GRAS crashes for Z >= 2 (Hugh Evans)
Hello,

I downloaded the GRAS3.4 updated tarball and successfully installed.

It worked perfectly now.

Thank you very much for the help.

Best Regards.

Leonardo.

Idea Re: GRAS crashes for Z >= 2  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   14 Nov, 2015
Re: Question Re: GRAS crashes for Z >= 2 (Leonardo Ghizoni)
Hello,

3.3 and 3.4 installations should be similar. Note that SpemvisCSV sub-package should be defined in the same directory structure - in similar place as it was in 3.3 case.

VI

Sad Re: GRAS crashes for Z >= 2  by Leonardo Ghizoni <Leonardo Ghizoni>,   14 Nov, 2015
Re: Idea Re: GRAS crashes for Z >= 2 (Vladimir Ivanchenko)
Really sorry, but I cannot make this work.

I created a second directory for GRAS 3.3 and reinstalled it to check my steps:

> . /home/lghizoni/Geant4/gean4.9.6-install/bin/geant4.sh

> . configure_and_install

-- The C compiler identification is GNU 4.8.4

-- The CXX compiler identification is GNU 4.8.4

-- Check for working C compiler: /usr/bin/cc

-- Check for working C compiler: /usr/bin/cc -- works

-- Detecting C compiler ABI info

-- Detecting C compiler ABI info - done

-- Check for working CXX compiler: /usr/bin/c++

-- Check for working CXX compiler: /usr/bin/c++ -- works

-- Detecting CXX compiler ABI info

-- Detecting CXX compiler ABI info - done

-- process subdir :analysis

-- process subdir :global

-- process subdir :physics

-- process subdir :histo

-- process subdir :geometry

-- process subdir :scoring

-- process subdir :SpenvisCSV

-- process subdir :field_models

-- process subdir :adjoint_physics

-- GRAS will be compiled with GDML!

-- Found XercesC: /usr/lib/x86_64-linux-gnu/libxerces-c.so

-- GRAS will be compiled with meshing analysis module!

-- Found ROOT 5.34/14 in /usr!!

-- GRAS will be compiled with ROOT

-- Configuring done

-- Generating done

-- Build files have been written to: /home/lghizoni/Geant4/gras-03-03_test/build Compilation of the code with make!

Then I do exactly the same for GRAS 3.4 and Geant4.10.01:

> . /home/lghizoni/Geant4/gean4.10.01-install/bin/geant4.sh

> . configure_and_install

But then I get:

-- The C compiler identification is GNU 4.8.4

-- The CXX compiler identification is GNU 4.8.4

-- Check for working C compiler: /usr/bin/cc

-- Check for working C compiler: /usr/bin/cc -- works

-- Detecting C compiler ABI info

-- Detecting C compiler ABI info - done

-- Check for working CXX compiler: /usr/bin/c++

-- Check for working CXX compiler: /usr/bin/c++ -- works

-- Detecting CXX compiler ABI info

-- Detecting CXX compiler ABI info - done

-- process subdir :analysis

-- process subdir :global

-- process subdir :physics

-- process subdir :histo

-- process subdir :geometry

-- process subdir :scoring

-- process subdir :SpenvisCSV

CMake Error at source/CMakeLists.txt:9 (add_subdirectory):
  add_subdirectory given source "SpenvisCSV" which is not an existing
  directory.

CMake Error at source/CMakeLists.txt:10 (get_directory_property):
  get_directory_property DIRECTORY argument provided but requested directory
  not found.  This could be because the directory argument was invalid or, it
  is valid but has not been processed yet.

CMake Error at source/CMakeLists.txt:11 (get_directory_property):
  get_directory_property DIRECTORY argument provided but requested directory
  not found.  This could be because the directory argument was invalid or, it
  is valid but has not been processed yet.

-- process subdir :field_models

-- process subdir :adjoint_physics

-- GRAS will be compiled with GDML!

-- Found XercesC: /usr/lib/x86_64-linux-gnu/libxerces-c.so

-- GRAS will be compiled with meshing analysis module!

-- Found ROOT 5.34/14 in /usr!!

-- GRAS will be compiled with ROOT

-- Configuring incomplete, errors occurred!

See also "/home/lghizoni/Geant4/gras-03-04/build/CMakeFiles/CMakeOutput.log".

Compilation of the code with make!

make: *** No targets specified and no makefile found. Stop.

Installation of the code!

make: *** No rule to make target `install'. Stop.

Don't know if I'm missing a step :(

Thanks a lot.

None Re: GRAS crashes for Z >= 2  by Svetlana Shasharina <Svetlana Shasharina>,   14 Nov, 2015
Re: Sad Re: GRAS crashes for Z >= 2 (Leonardo Ghizoni)
Maybe comment out add_subdirectory with SpenvisCSV in CMakeLists.txt?
Sveta

On 11/14/15 4:28 PM, Leonardo Ghizoni wrote:
>
> *** Discussion title: Space Applications
>
> Really sorry, but I cannot make this work.
>
> I created a second directory for GRAS 3.3 and reinstalled it to check my
> steps:
>
>> . /home/lghizoni/Geant4/gean4.9.6-install/bin/geant4.sh
>
>> . configure_and_install
>
> -- The C compiler identification is GNU 4.8.4
>
> -- The CXX compiler identification is GNU 4.8.4
>
> -- Check for working C compiler: /usr/bin/cc
>
> -- Check for working C compiler: /usr/bin/cc -- works
>
> -- Detecting C compiler ABI info
>
> -- Detecting C compiler ABI info - done
>
> -- Check for working CXX compiler: /usr/bin/c++
>
> -- Check for working CXX compiler: /usr/bin/c++ -- works
>
> -- Detecting CXX compiler ABI info
>
> -- Detecting CXX compiler ABI info - done
>
> -- process subdir :analysis
>
> -- process subdir :global
>
> -- process subdir :physics
>
> -- process subdir :histo
>
> -- process subdir :geometry
>
> -- process subdir :scoring
>
> -- process subdir :SpenvisCSV
>
> -- process subdir :field_models
>
> -- process subdir :adjoint_physics
>
> -- GRAS will be compiled with GDML!
>
> -- Found XercesC: /usr/lib/x86_64-linux-gnu/libxerces-c.so
>
> -- GRAS will be compiled with meshing analysis module!
>
> -- Found ROOT 5.34/14 in /usr!!
>
> -- GRAS will be compiled with ROOT
>
> -- Configuring done
>
> -- Generating done
>
> -- Build files have been written to:
> /home/lghizoni/Geant4/gras-03-03_test/build Compilation of the code with
> make!
>
> Then I do exactly the same for GRAS 3.4 and Geant4.10.01:
>
>> . /home/lghizoni/Geant4/gean4.10.01-install/bin/geant4.sh
>
>> . configure_and_install
>
> But then I get:
>
> -- The C compiler identification is GNU 4.8.4
>
> -- The CXX compiler identification is GNU 4.8.4
>
> -- Check for working C compiler: /usr/bin/cc
>
> -- Check for working C compiler: /usr/bin/cc -- works
>
> -- Detecting C compiler ABI info
>
> -- Detecting C compiler ABI info - done
>
> -- Check for working CXX compiler: /usr/bin/c++
>
> -- Check for working CXX compiler: /usr/bin/c++ -- works
>
> -- Detecting CXX compiler ABI info
>
> -- Detecting CXX compiler ABI info - done
>
> -- process subdir :analysis
>
> -- process subdir :global
>
> -- process subdir :physics
>
> -- process subdir :histo
>
> -- process subdir :geometry
>
> -- process subdir :scoring
>
> -- process subdir :SpenvisCSV
>
> CMake Error at source/CMakeLists.txt:9 (add_subdirectory):
>    add_subdirectory given source "SpenvisCSV" which is not an existing
>    directory.
>
> CMake Error at source/CMakeLists.txt:10 (get_directory_property):
>    get_directory_property DIRECTORY argument provided but requested directory
>    not found.  This could be because the directory argument was invalid or, it
>    is valid but has not been processed yet.
>
> CMake Error at source/CMakeLists.txt:11 (get_directory_property):
>    get_directory_property DIRECTORY argument provided but requested directory
>    not found.  This could be because the directory argument was invalid or, it
>    is valid but has not been processed yet.
>
> -- process subdir :field_models
>
> -- process subdir :adjoint_physics
>
> -- GRAS will be compiled with GDML!
>
> -- Found XercesC: /usr/lib/x86_64-linux-gnu/libxerces-c.so
>
> -- GRAS will be compiled with meshing analysis module!
>
> -- Found ROOT 5.34/14 in /usr!!
>
> -- GRAS will be compiled with ROOT
>
> -- Configuring incomplete, errors occurred!
>
> See also
> "/home/lghizoni/Geant4/gras-03-04/build/CMakeFiles/CMakeOutput.log".
>
> Compilation of the code with make!
>
> make: *** No targets specified and no makefile found. Stop.
>
> Installation of the code!
>
> make: *** No rule to make target `install'. Stop.
>
> Don't know if I'm missing a step :(
>
> Thanks a lot.
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/114/1/1/1/1/1.html
>

Ok Re: GRAS crashes for Z >= 2  by Leonardo Ghizoni <Leonardo Ghizoni>,   14 Nov, 2015
Re: None Re: GRAS crashes for Z >= 2 (Svetlana Shasharina)
Hello,

Thank you for your tip.

Following that, I checked the .tar files and found out that for GRAS 3.4 the /source/SpenvisCSV is missing.

I copied that from GRAS 3.3 and finally installed it!

I had a couple of warning messages like:

In file included from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/include/GRASAnalysisModule.hh:49:0,
                 from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/include/GRASDoseAnalysisModule.hh:40,
                 from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/include/GRASEqDoseAnalysisModule.hh:40,
                 from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/src/GRASEqDoseAnalysisModule.cc:33:
/home/lghizoni/Geant4/gras-03-04_test/source/SpenvisCSV/include/SpenvisCSV.hh: In member function void SpenvisCSV::SetPrefix(std::string):
/home/lghizoni/Geant4/gras-03-04_test/source/SpenvisCSV/include/SpenvisCSV.hh:299:29: warning: declaration of s shadows a global declaration [-Wshadow]
   void SetPrefix( STRING s) { prefix = s; };
                             ^
But the installation goes on and finishes! Thanks a lot!

Should I worry about this warnings during installation?

Regards.

Leonardo

None Re: GRAS crashes for Z >= 2  by Svetlana Shasharina <Svetlana Shasharina>,   15 Nov, 2015
Re: Ok Re: GRAS crashes for Z >= 2 (Leonardo Ghizoni)
Hello Leonardo,
I doubt that this warning is important.  You could probably disable such 
warning using some compiler flags.
Cheers,
Sveta

On 11/14/15 7:25 PM, Leonardo Ghizoni wrote:
>
> *** Discussion title: Space Applications
>
> Hello,
>
> Thank you for your tip.
>
> Following that, I checked the .tar files and found out that for GRAS 3.4
> the /source/SpenvisCSV is missing.
>
> I copied that from GRAS 3.3 and finally installed it!
>
> I had a couple of warning messages like:
>
> In file included from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/include/GRASAnalysisModule.hh:49:0,
>                   from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/include/GRASDoseAnalysisModule.hh:40,
>                   from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/include/GRASEqDoseAnalysisModule.hh:40,
>                   from /home/lghizoni/Geant4/gras-03-04_test/source/analysis/src/GRASEqDoseAnalysisModule.cc:33:
> /home/lghizoni/Geant4/gras-03-04_test/source/SpenvisCSV/include/SpenvisCSV.hh: In member function void SpenvisCSV::SetPrefix(std::string):
> /home/lghizoni/Geant4/gras-03-04_test/source/SpenvisCSV/include/SpenvisCSV.hh:299:29: warning: declaration of s shadows a global declaration [-Wshadow]
>     void SetPrefix( STRING s) { prefix = s; };
>                               ^
> But the installation goes on and finishes! Thanks a lot!
>
> Should I worry about this warnings during installation?
>
> Regards.
>
> Leonardo
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/114/1/1/1/1/1/1/1.html
>

Idea Re: GRAS crashes for Z >= 2  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   15 Nov, 2015
Re: None Re: GRAS crashes for Z >= 2 (Svetlana Shasharina)
Hello,

yes, the warning can be ignore. Also if you upload SpenvisCSV from the trunk of the same site as GRAS, you will get an updated version with this compillation problem fixed.

VI
Question Simulation of anisotropic particle fluxes  by Michael Milde <Michael Milde>,   23 Sep, 2015
Hello,

I want to simulate the response of my detector in the anisotropic flux of trapped protons in the South Atlantic Anomaly. The angular distribution for the flux is calculated by the SPENVIS webtool in form of a histogram. At the moment I am not sure how to build the particle gun in a way that I have the same flux at every position in the world volume.

Maybe someone has experience in creating such a gun. Thanks in advance.

Greetings,

Michael

None Re: Simulation of anisotropic particle fluxes  by Hugh Evans <Hugh Evans>,   23 Sep, 2015
Re: Question Simulation of anisotropic particle fluxes (Michael Milde)
On Wed, 23 Sep 2015 11:50:56 GMT, Michael Milde wrote:
> 
> I want to simulate the response of my detector in the anisotropic flux
> of trapped protons in the South Atlantic Anomaly. The angular

Make a series of runs with a parallel beam at various directions to the detector. This will give you a directional response function which you can then fold with the SPENVIS directional spectrum to determine the counts to be expected.

If you simulate the actual environment with a specific anisotropic particle source, then your results are not valid for a different anisotropic environment. If you build the directional response function, e.g. RF(E, theta, phi), for the instrument then you can test it against numerous anisotropic environments (and isotropic).

See: http://dx.doi.org/10.1109/TNS.2010.2041253

Regards Hugh

None Re: Simulation of anisotropic particle fluxes  by Hugh Evans <Hugh Evans>,   24 Sep, 2015
Re: None Re: Simulation of anisotropic particle fluxes (Hugh Evans)
Hi,

For a more detailed description of how to achieve your aims, have a look at M. Siegl's masters thesis:

http://epubl.ltu.se/1653-0187/2009/063/LTU-PB-EX-09063-SE.pdf

Ok Re: Simulation of anisotropic particle fluxes  by Michael Milde <Michael Milde>,   01 Oct, 2015
Re: None Re: Simulation of anisotropic particle fluxes (Hugh Evans)
Thank you for your answer!

Question how to find the cross section data of the nuclear reactions  by liyong <liyong>,   16 Mar, 2015
Dear all,

I am trying to simulate the generation of cosmogenic nuclei 10Be and 26Al in lunar soil. I didn't find the cross section data of the reaction 'O(n,x)10Be' in G4NDL4.5/IsotopeProduction/CrossSection, however, 10Be is produced in the simulation of 100-200MeV neutron interact with the Oxygen. Could you tell me which cross section data is used in this reaction. And could you tell how can I find the cross section data of the nuclear reactions, such as 'O(p,x)10Be'.

Thank you in advance. Liyong

None Re: how to find the cross section data of the nuclear reactions  by Dennis H. Wright <Dennis H. Wright>,   16 Mar, 2015
Re: Question how to find the cross section data of the nuclear reactions (liyong)
For incident neutrons (and protons) above 20 MeV, Geant4 does not have specific channel cross sections. The final state particles are generated by models which may produce such channels, but these models do not use specific channel cross section data.

Question Initial run of GRAS-03-03 with geant4.9.6.p04  by Richard Gillham Darnley <Richard Gillham Darnley>,   04 Mar, 2015
Hi,

I have just installed geant4.9.6.p04 and GRAS-03-03 on my linux computer. I have enabled GDML options and ran example G01 to test my basic GDML and XercesC install. This example worked fine.

When running the configure_and_install.sh script for GRAS-03-03 I had to add the following cmake options so that it could find XercesC:

-DXERCESC_LIBRARY=/home/richard/xercesc/xerces-c-src_2_8_0/lib/libxerces-c.so -DXERCESC_INCLUDE_DIR=/home/richard/xercesc/xerces-c-src_2_8_0/include

Now when I attempt to run gras by typing 'gras' in the terminal I get the following message:

gras: error while loading shared libraries: libxerces-c.so.28: cannot open shared object file: No such file or directory

This file does exist (its in the same location as libxerces-c.so). How should I tackle this problem? Should I change the library cmake option to look for 'libxerces-c.so.28' instead or is there another step in the process that I am missing?

Thank you in advance for any help,

Richard

Idea Re: Initial run of GRAS-03-03 with geant4.9.6.p04  by Michael H. Kelsey <Michael H. Kelsey>,   04 Mar, 2015
Re: Question Initial run of GRAS-03-03 with geant4.9.6.p04 (Richard Gillham Darnley)
On Wed, 04 Mar 2015 12:05:37 GMT, Richard Gillham Darnley wrote:
> I have just installed geant4.9.6.p04 and GRAS-03-03 on my linux
> computer. I have enabled GDML options and ran example G01 to test my
> basic GDML and XercesC install. This example worked fine.
> 
> When running the configure_and_install.sh script for GRAS-03-03 I had to
> add the following cmake options so that it could find XercesC:
> 
> -DXERCESC_LIBRARY=/home/richard/xercesc/xerces-c-src_2_8_0/lib/libxerces-c.so
> -DXERCESC_INCLUDE_DIR=/home/richard/xercesc/xerces-c-src_2_8_0/include
> 
> Now when I attempt to run gras by typing 'gras' in the terminal I get
> the following message:
> 
> gras: error while loading shared libraries: libxerces-c.so.28: cannot
> open shared object file: No such file or directory

Add the XercesC library directory to your LD_LIBRARY_PATH.  This isn't done for your by G4; you have to do it yourself.
                 -- Michael Kelsey

Feedback Re: Initial run of GRAS-03-03 with geant4.9.6.p04  by Richard Gillham Darnley <Richard Gillham Darnley>,   04 Mar, 2015
Re: Idea Re: Initial run of GRAS-03-03 with geant4.9.6.p04 (Michael H. Kelsey)
That's sorted it thank you Michael!

Richard

None Re: Initial run of GRAS-03-03 with geant4.9.6.p04  by Svetlana Shasharina <Svetlana Shasharina>,   04 Mar, 2015
Re: Question Initial run of GRAS-03-03 with geant4.9.6.p04 (Richard Gillham Darnley)
You might want to add some variables in cmake:

   -DGEANT4_INSTALL_DATA:BOOL=ON
   -DGEANT4_INSTALL_DATADIR:PATH= ...
   -DGEANT4_USE_GDML:BOOL=ON
   -DXERCESC_ROOT_DIR:PATH=...
   -DXERCESC_INCLUDE_DIR:PATH=...
   -DXERCESC_LIBRARY:FILEPATH='${xercescdir}/lib/libxerces-c.so

Cheers,
Sveta

On 3/4/15 5:05 AM, Richard Gillham Darnley wrote:
>
> *** Discussion title: Space Applications
>
> Hi,
>
> I have just installed geant4.9.6.p04 and GRAS-03-03 on my linux
> computer. I have enabled GDML options and ran example G01 to test my
> basic GDML and XercesC install. This example worked fine.
>
> When running the configure_and_install.sh script for GRAS-03-03 I had to
> add the following cmake options so that it could find XercesC:
>
> -DXERCESC_LIBRARY=/home/richard/xercesc/xerces-c-src_2_8_0/lib/libxerces-c.so
> -DXERCESC_INCLUDE_DIR=/home/richard/xercesc/xerces-c-src_2_8_0/include
>
> Now when I attempt to run gras by typing 'gras' in the terminal I get
> the following message:
>
> gras: error while loading shared libraries: libxerces-c.so.28: cannot
> open shared object file: No such file or directory
>
> This file does exist (its in the same location as libxerces-c.so). How
> should I tackle this problem? Should I change the library cmake option
> to look for 'libxerces-c.so.28' instead or is there another step in the
> process that I am missing?
>
> Thank you in advance for any help,
>
> Richard
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/111.html
>

Feedback Re: Initial run of GRAS-03-03 with geant4.9.6.p04  by Richard Gillham Darnley <Richard Gillham Darnley>,   04 Mar, 2015
Re: None Re: Initial run of GRAS-03-03 with geant4.9.6.p04 (Svetlana Shasharina)
Hi Sveta,

Do you mean I should add these cmake variables when I install geant4 or gras?

I used ccmake when installing geant4 and in this gui I set the variables you mention to the values you suggested.

By the way I tried changing the cmake variable XERCESC_LIBRARY from libxerces-c.so to libxerces-c.so.28 and I still get the same 'error' message when attempting to run the gras executable.

Richard

None I need to study the depth dose-distributions and partial fragmentation cross sections or yields of charged nuclear fragm  by Wu Zheng <Wu Zheng>,   07 Nov, 2014
For example ,I want to Simulated fragmentation distribution as a function of the fragment Z after 1 g/cm of Al hit by 1 GeV/nucleon Fe ions by geant4. Who can give me some suggestions?

Question Dose Normalization  by Leonardo Ghizoni <Leonardo Ghizoni>,   06 Oct, 2014
Hello Experts,

I'm having some difficulties when trying to normalize my outputs, like the Total Dose.

First I'm running with a simple geometry: a spherical target sorrounded by a spherical shell with 2mm thickness.

To compute the dose, I'm using the primitive scorer G4PSDoseDeposit and using GPS as the source.

I took a look at a ppt document of G. Santin about normalization, and as I understood, the "real world" Dose is calculated as:

Dr = Nr*Ds/Ns,

where Nr is the number of particles in the real world, Ds is the dose calculated in the simulation and Ns is the number of events simulated, right?

Now, the "real world" number of particles Nr is calculated by the flux. That's where I'm a little confused. I do have the fluxes as functions of the energy, in a table calculated by Spenvis and the respective macro created. As I understad, the number Nr is calculated by:

Nr = flux * 4*pi^2*r^2.

I don't know which flux to use, since I have a table based on energies. And the radius is defined by me on the source, right? I defined the source like this:

/gps/particle proton

/gps/ene/type Arb

/gps/hist/type arb

/gps/hist/point 1.000000E-01 2.407800E+01

/gps/hist/point 1.500000E-01 2.397600E+01

/gps/hist/point 2.000000E-01 1.974300E+01

/gps/hist/point 3.000000E-01 1.135400E+01

/gps/hist/point 4.000000E-01 1.059100E+01

/gps/hist/point 5.000000E-01 9.840100E+00

/gps/hist/point 6.000000E-01 1.154300E+01

/gps/hist/point 7.000000E-01 1.277300E+01

/gps/hist/point 1.000000E+00 8.546000E+00

/gps/hist/point 1.500000E+00 3.924800E+00

/gps/hist/point 2.000000E+00 3.838800E+00

/gps/hist/point 3.000000E+00 3.667500E+00

/gps/hist/point 4.000000E+00 3.831800E+00

/gps/hist/point 5.000000E+00 3.993600E+00

/gps/hist/point 6.000000E+00 4.341400E+00

/gps/hist/point 7.000000E+00 4.587900E+00

/gps/hist/point 1.000000E+01 3.820900E+00

/gps/hist/point 1.500000E+01 2.932800E+00

/gps/hist/point 2.000000E+01 2.538000E+00

/gps/hist/point 3.000000E+01 2.066400E+00

/gps/hist/point 4.000000E+01 1.757500E+00

/gps/hist/point 5.000000E+01 1.592800E+00

/gps/hist/point 6.000000E+01 1.462600E+00

/gps/hist/point 7.000000E+01 1.370200E+00

/gps/hist/point 1.000000E+02 1.118000E+00

/gps/hist/point 1.500000E+02 7.635400E-01

/gps/hist/point 2.000000E+02 4.962900E-01

/gps/hist/point 3.000000E+02 2.196200E-01

/gps/hist/point 4.000000E+02 2.586700E-02

/gps/hist/inter Spline

/gps/pos/type Surface

/gps/pos/shape Sphere

/gps/pos/centre 0. 0. 0. mm

/gps/pos/radius 9 mm

/gps/ang/type cos

/gps/ang/mintheta 0.000E+00 deg

/gps/ang/maxtheta 9.000E+01 deg

/gps/source/list

So, my radius will be 9mm.

Finally, my normalized dose changes values when I change the number of primary events...this sounds incorret, since I'm normalizing it.

I know I'm doing it wrong, just don't know where.

Please help? I'm really having a hard time on this.

Thank you in advance.

Best Regards, Leonardo.

Question modeling space environment in testing facilities  by Svetlana Shasharina <Svetlana Shasharina>,   30 Jul, 2014
Sorry, if I am posting the second time (do not see my first post).

I am given integral fluences for electrons and protons (Europa environment). The testing facility will give us particular monoenergetic fluxes in microsec pulses in particular energies. What is the accepted practice to reproduce the TID effects in such facilities?

Thank you, Sveta

Question calculating secondary electrons from electron source (using GRAS)  by Svetlana Shasharina <Svetlana Shasharina>,   30 Jul, 2014
Hi everybody,

I need to calculate the flux of "extra" electrons produced by enviroment electrons in Europa environment. I have beed using GRAS to do my simulations and can calculate fluxes "to", "from" and "between" volumes but I cannot directly calculate the flux of the new electrons that might appear due to e radiation.

Questions: 1. Can I ignore the secondary electrons from electron sources and consider electrons produced by protons dominating (I know how to calculate secondary electrons when I have ion source:-)?

2. Can I estimate the secondary flux by subtracting "in" flux from the "from" flux? I understand that the logic is not flawless as some incident electrons might not leave the volume.

Thank you, Sveta

Question How to compute Dose with GPS?  by Leonardo Ghizoni <Leonardo Ghizoni>,   22 Jul, 2014
Hello,

I'm using the GPS to simulate the space radiation environment...

What would be the right angular distribution to use, assuming I want an omnidirectional distribution?

Other question: how do I compute the dose on a specified part of my geometry usin the GPS? And finally, is it possible to compute the dose on more than one object on the same run?

Thank you in advance.

Best regards. Leonardo

None Re: How to compute Dose with GPS?  by Hugh Evans <Hugh Evans>,   23 Jul, 2014
Re: Question How to compute Dose with GPS? (Leonardo Ghizoni)
Use a cosine angular distribution.

    /gps/ang/type cos

This mimics the omnidirectional space environment.

You could also have a look at the SPENVIS web site (www.spenvis.oma.be), which provides GPS macro files from the space environment models for us in Mulassis and GRAS.

Regards Hugh

Question Re: How to compute Dose with GPS?  by Leonardo Ghizoni <Leonardo Ghizoni>,   23 Jul, 2014
Re: None Re: How to compute Dose with GPS? (Hugh Evans)
Thank you very much for the answer.

Regarding the other questions, do you have any advice?

1. How do Icompute the total dose using GPS? 2. Is it possible to compute the dose on more than one object on the same simulation?

Thank you again.

Regards. Leonardo

None Re: How to compute Dose with GPS?  by Hugh Evans <Hugh Evans>,   23 Jul, 2014
Re: Question Re: How to compute Dose with GPS? (Leonardo Ghizoni)
Hi,

I'm not entirely sure I understand your question. Are you using GRAS or Mulassis for the calculation or another Geant4 application?

If you're using either GRAS or Mulassis, then yes it is possible, not through the GPS macros, but through the GRAS or Mulassis analysis macro commands. If you're using another application, then you'll have to read the application's help documentation.

The facilities of this forum is not really ideal for helping with those macro commands.

However, as previously suggested by Sveta, try to use SPENVIS in the first instance, as it allows you to run a GRAS or Mulassis simulation via a web interface (it's a bit old, but functional).

Hugh

Question Re: How to compute Dose with GPS?  by Leonardo Ghizoni <Leonardo Ghizoni>,   23 Jul, 2014
Re: None Re: How to compute Dose with GPS? (Hugh Evans)
Dear Hugh,

Thank you very much for your answer.

Yes, I'm using GRAS.

As a last question, and maybe a very basic one, if I'm simulating the dose on an object during the lifetime of a satellite, say 4 years, how can I know the number of particles to simulate, for it to be a realistic model?

Thank you again.

Regards. Leonardo

None Re: How to compute Dose with GPS?  by Hugh Evans <Hugh Evans>,   24 Jul, 2014
Re: Question Re: How to compute Dose with GPS? (Leonardo Ghizoni)
Hi,

If you mean how many primaries to generate to get good statistics, well, you'll just have to play with the /run/beamOn command, increasing the number of primaries until you obtain the statistics you need.

If you mean normalisation of the output, I'd recommend using SPENVIS, as it will (to a large extent) provide a normalised GPS macro file for the given environment and mission duration and produce a basic set of GRAS macro files that can then be downloaded and used with your local installation.

Normalisation is always a confusing topic. For a write up on calculating the normalisation factor to be used, I direct you to a report G. Santin and I produced a few years back and have attached.

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/07/24/00.12-11923-malizationFactor-V1.3.pdf

Best of luck! Hugh

Question Re: How to compute Dose with GPS?  by Leonardo Ghizoni <Leonardo Ghizoni>,   03 Oct, 2014
Re: None Re: How to compute Dose with GPS? (Hugh Evans)
Dear Hugh,

Thank you for your reply.

I'm trying to normalize my dose calculated by primitive scores now.

As I understood, the "real world" Dose is calculated as:

Dr = Nr*Ds/Ns,

where Nr is the number of particles in the real world, Ds is the dose calculated in the simulation and Ns is the number of events simulated, right?

Now, the "real world" number of particles Nr is calculated by the flux. That's where I'm a little confused. I do have the fluxes as functions of the energy, in a table calculated by spenvis and the respective macro created. As I understad, the number Nr is calculated by:

Nr = flux * 4*pi^2*r^2.

I don't know which flux to use, since I have a table based on energies. And the radius is defined by me on the source, right? I defined the source like this:

/gps/particle proton

/gps/ene/type Arb

/gps/hist/type arb

/gps/hist/point 1.000000E-01 2.407800E+01

/gps/hist/point 1.500000E-01 2.397600E+01

/gps/hist/point 2.000000E-01 1.974300E+01

/gps/hist/point 3.000000E-01 1.135400E+01

/gps/hist/point 4.000000E-01 1.059100E+01

/gps/hist/point 5.000000E-01 9.840100E+00

/gps/hist/point 6.000000E-01 1.154300E+01

/gps/hist/point 7.000000E-01 1.277300E+01

/gps/hist/point 1.000000E+00 8.546000E+00

/gps/hist/point 1.500000E+00 3.924800E+00

/gps/hist/point 2.000000E+00 3.838800E+00

/gps/hist/point 3.000000E+00 3.667500E+00

/gps/hist/point 4.000000E+00 3.831800E+00

/gps/hist/point 5.000000E+00 3.993600E+00

/gps/hist/point 6.000000E+00 4.341400E+00

/gps/hist/point 7.000000E+00 4.587900E+00

/gps/hist/point 1.000000E+01 3.820900E+00

/gps/hist/point 1.500000E+01 2.932800E+00

/gps/hist/point 2.000000E+01 2.538000E+00

/gps/hist/point 3.000000E+01 2.066400E+00

/gps/hist/point 4.000000E+01 1.757500E+00

/gps/hist/point 5.000000E+01 1.592800E+00

/gps/hist/point 6.000000E+01 1.462600E+00

/gps/hist/point 7.000000E+01 1.370200E+00

/gps/hist/point 1.000000E+02 1.118000E+00

/gps/hist/point 1.500000E+02 7.635400E-01

/gps/hist/point 2.000000E+02 4.962900E-01

/gps/hist/point 3.000000E+02 2.196200E-01

/gps/hist/point 4.000000E+02 2.586700E-02

/gps/hist/inter Spline

/gps/pos/type Surface

/gps/pos/shape Sphere

/gps/pos/centre 0. 0. 0. mm

/gps/pos/radius 9 mm

/gps/ang/type cos

/gps/ang/mintheta 0.000E+00 deg

/gps/ang/maxtheta 9.000E+01 deg

/gps/source/list

So, my radius will be 9mm.

Finally, my normalized dose changes values when I change the number of primary events...this sounds incorret, since I'm normalizing it.

Could you please help me? I'm having a hard time on this.

Thank you very much.

Best regards Leonardo.

None Re: How to compute Dose with GPS?  by Svetlana Shasharina <Svetlana Shasharina>,   23 Jul, 2014
Re: Question Re: How to compute Dose with GPS? (Leonardo Ghizoni)
Dear Leonardo,
Try http://www.spenvis.oma.be/.  You will need to register and learn to 
use their interface.  But spenvis is great for what you want to do!
Sveta

On 7/23/14 6:59 AM, Leonardo Ghizoni wrote:
>
> *** Discussion title: Space Applications
>
> Thank you very much for the answer.
>
> Regarding the other questions, do you have any advice?
>
> 1. How do Icompute the total dose using GPS? 2. Is it possible to
> compute the dose on more than one object on the same simulation?
>
> Thank you again.
>
> Regards. Leonardo
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/106/1/1.html
>

Question Using defualt GRAS histograms instead of AIDA  by Svetlana Shasharina <Svetlana Shasharina>,   10 Jun, 2014
I see the following lines in a g4mac generated by Spenvis:

/gras/histo/fileName spenvis_gras31

/gras/histo/AIDAFileType root

Does this imply that the output uses AIDA? How do I change these lines in order not to depend on AIDA? Should I just ommit the second line?

Thanks, Sveta

Idea Re: Using defualt GRAS histograms instead of AIDA  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   01 Jul, 2014
Re: Question Using defualt GRAS histograms instead of AIDA (Svetlana Shasharina)
Hello,

sorry for the late reply, please, try csv output type.

VI

None Model a crossing muon in a ccd cell  by Pierre <Pierre>,   14 May, 2014
Dear Geant4 users,

I am really new in the use of G4 and as its mentionned in the title, I would like to create a box representing my ccd cell and measure the energy deposited by crossing muons which come from isotropic (from a sphere).

I have well written the DetectorConstruction.cc and the PhysicsList.cc files but I dont know exactly how to code the run.cc and primarygenerator.cc files. I attached these files.

Precisely I don't know how to code the incident muons coming from the sphere.

I am a little bit lost in the use og Geant4, everything is still not clear for me. I hope I could get some help for that task.

Cheers

Pierre

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/05/14/04.39-88-DetectorConstruction.cc
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/05/14/04.39-34516-PhysicsList.cc
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/05/14/04.39-46915-PrimaryGeneratorAction.cc
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/05/14/04.39-83636-Run.cc

Question Re: Model a crossing muon in a ccd cell  by Pierre <Pierre>,   16 May, 2014
Re: None Model a crossing muon in a ccd cell (Pierre)
Hello everyone,

I realized that it was better for me to use the GeneralParticleSource in order to simulate the radiative environment.

So here is my code :

------------------------------------------------

G4VPrimaryGenerator* PrimaryGeneratorAction::InitializeGPS()
{
  G4GeneralParticleSource* gps = new G4GeneralParticleSource();

  // setup details easier via UI commands see gps.mac

  // particle type
  G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
  G4ParticleDefinition* muon = particleTable->FindParticle("mu-");  
  gps->GetCurrentSource()->SetParticleDefinition(muon);

  // set energy distribution
  G4SPSEneDistribution* energy_distribution = gps->GetCurrentSource()->GetEneDist() ;
  energy_distribution->SetEnergyDisType("Mono"); // or gauss
  energy_distribution->SetMonoEnergy(10*MeV);

  // set position distribution
  G4SPSPosDistribution* position_distribution = gps->GetCurrentSource()->GetPosDist();
  position_distribution->SetPosDisType("Beam");  // or Point,Plane,Volume,Beam
  position_distribution->SetCentreCoords(G4ThreeVector(0.0*cm,0.0*cm,0.0*cm));
  position_distribution->SetBeamSigmaInX(0.0*mm);
  position_distribution->SetBeamSigmaInY(0.0*mm);

  // set angular distribution
  G4SPSAngDistribution* angular_distribution = gps->GetCurrentSource()->GetAngDist();
  angular_distribution->SetParticleMomentumDirection( G4ThreeVector(0., 0., 0.) );

  //valid options are:
  // iso, cos, user, planar, beam2d, beam1d
  angular_distribution->SetAngDistType("iso");
  angular_distribution->SetBeamSigmaInAngX(0.0*mrad);
  angular_distribution->SetBeamSigmaInAngY(0.0*mrad);
  angular_distribution->DefineAngRefAxes("angref1",G4ThreeVector(-1.,0.,0.));

  return gps;

}

------------------------------------------------

My question is how to modify the GPS in order to simulate a sphere (an isotropic source which contain a smaller detector) where particles are generated from and cross the inside in a random way ? And calculate the energy deposited in the detector by the particles which crossed the detector ?

Thank you in advance,

Pierre

None Re: Model a crossing muon in a ccd cell  by Pierre <Pierre>,   19 May, 2014
Re: Question Re: Model a crossing muon in a ccd cell (Pierre)
Moreover, I succeed to get an isotropic source (see the attach picture1) but I would like to have crossing rays which start from a point on the surface of the sphere and does not focused toward the centre.

Does anyone have an idea ?

Thank you in advance,

Pierre

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/05/19/00.53-84139-radiative_env.png

None Re: Model a crossing muon in a ccd cell  by michel maire <michel maire>,   19 May, 2014
Re: None Re: Model a crossing muon in a ccd cell (Pierre)
On Mon, 19 May 2014 08:17:04 GMT, Pierre wrote:
> Moreover, I succeed to get an isotropic source (see the attach picture1)
> but I would like to have crossing rays which start from a point on the
> surface of the sphere and does not focused toward the centre.
> 
> Does anyone have an idea ?

 You may have a look at example extended/eventgenerator/particleGun  (see Readme), although it uses simple particle gun, not gps.

None Re: Model a crossing muon in a ccd cell  by John Allison <John Allison>,   19 May, 2014
Re: None Re: Model a crossing muon in a ccd cell (michel maire)
This gave me isotropic radiation in a cavity:

  /gps/pos/type Surface
  /gps/pos/shape Sphere
  /gps/pos/radius {cavityRadius}
  /gps/ang/type cos

Question extra parts add to TID: unexpected result  by Svetlana Shasharina <Svetlana Shasharina>,   05 May, 2014
Hi I am using SPENVIS/GRAS. I calculated fluxes and TIDs in two configurations: (1) cylindrical shield with an opening on top (2) the same shield plus a hollow cone sitting on the opening and having the same size of opening. I used the same fluxes and spherical source in both cases. To my surprise, the TID from electrons of the "detector" inside the cylindrical shields and a proton flux on them was higher in the second case. I then added calculations of fluxes from the cone and it was zero. Flux between the cone and the detector was zero too. I am puzzled by the result. Any ideas? Thanks, Sveta

Note Re: extra parts add to TID: unexpected result  by Svetlana Shasharina <Svetlana Shasharina>,   01 Jul, 2014
Re: Question extra parts add to TID: unexpected result (Svetlana Shasharina)
Just to close this issue. The problem was solved by switching to Geant4 9.6.3 (from 9.6.2). Thank you, Sveta

Question local GRAS generating empty histograms  by Svetlana Shasharina <Svetlana Shasharina>,   05 Apr, 2014
I used spenvis and ran TID analysis. I tried to run the same mac and gdml files locally and am getting validation errors:

G4GDML: VALIDATION ERROR! ID value 'v01' is not unique at line: 99
G4GDML: VALIDATION ERROR! ID value 'v02' is not unique at line: 104
G4GDML: VALIDATION ERROR! ID value 'v03' is not unique at line: 109
G4GDML: VALIDATION ERROR! ID value 'v04' is not unique at line: 114
G4GDML: VALIDATION ERROR! ID value 'v05' is not unique at line: 119
G4GDML: VALIDATION ERROR! ID attribute 'G4_Ta' is referenced but was never declared at line: 131
 etc

and getting empty histograms.

Once I follow the suggestion from https://www.spenvis.oma.be/forum/viewtopic.php?f=27&t=228 (although I do not this additional line in any gdml examples) and am still getting the above errors and empty histograms (see attached).

Should I install AIDA?

Thanks, Sveta

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/04/05/06.57-30254-nvis_gras31_e_local.g4mac
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/04/05/06.57-66185-spenvis_suda.gdml
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/04/05/06.57-33506-spenvis_gras31.csv

Question Normalization way for a generating sphere  by Manuel Castro Avila <Manuel Castro Avila>,   20 Mar, 2014
Hello everyone,

I am trying to normalize a counting rate in my simulation. I want to put it in units of counts cm^{-2} s^{-1} kev{-1}

In my simulation I am considering the input spectrum from the SPENVIS system (SPENVIS give me the spectrum in units of particles cm{-2} s^{-1} MeV{-1},
 I am considering the background produced by trapped protons and implemented into GEANT4 via /gps/hist/point).

So, using the input spectrum, I am generating a number N of events from a sphere's surface that hit a circular area of radius r. This circular area represents my detector.

Now, to normalize I proceed on this way:

-From the simulation I get the energy deposited for each event in my detector. Using these values I build a histogram in the energy range I am considering and I get a spectrum in Counts keV^{-1}. Am I right?
-Now, integrating (numerically) the spectrum from SPENVIS in the energy range, I have a flux in particles cm{-2} s{-1} in that energy range and using the geometrical factor
  (for a generating sphere is 2*pi*Acirc, where Acirc is the detector's area), I can calculate what is the integration time corresponding with the number N of events I am considering. Now dividied by
  a integration time I have the spectrum in counts kev{-1} s{-1}.
-Finally, as I know the area of my detector, dividing the previous result by the detector's area I have a spectrum in counts cm{-1} s{-1} kev{-1}.

My question is, am I proceeding on the right way?

Any idea..

Thanks

Manuel

Question CREME_M1_GCR_Flux_Spectra.xlt  by Ivan Brilkov <Ivan Brilkov>,   14 Mar, 2014
I've tried to use that file to to get fluxes in gps format: http://geant4.esa.int/tl_files/geant4/resources/CREME_M1_GCR_Flux_Spectra.xlt But macros seems not working in my version of Excel, in what version it works correctly?

PS: is still available Qinetiq sites about gps, mulassis, and others: http://reat.space.qinetiq.com/mulassis/

None Re: CREME_M1_GCR_Flux_Spectra.xlt  by Hugh Evans <Hugh Evans>,   17 Mar, 2014
Re: Question CREME_M1_GCR_Flux_Spectra.xlt (Ivan Brilkov)
Hi,

There are no macros in the file, so it should work with all recent versions of Excel.

The only cells to update are the Yellow ones (Element, year and minimum energy) on the G4-GPS sheet.

Note: energies below 10 MeV are not supported by the CREME-86 model on which the spreadsheet is based.

You can also obtain GCR spectra in G4-GPS format using SPENVIS (http://www.spenvis.oma.be). This includes the more recent GCR models (ISO-15390, etc) as well as trapped and solar particle models.

Hugh

On Fri, 14 Mar 2014 11:11:25 GMT, Ivan Brilkov wrote:

> I've tried to use that file to to get fluxes in gps format:
> http://geant4.esa.int/tl_files/geant4/resources/CREME_M1_GCR_Flux_Spectra.xlt
> But macros seems not working in my version of Excel, in what version it
> works correctly?
> 
> PS: is still available Qinetiq sites about gps, mulassis, and others:
> http://reat.space.qinetiq.com/mulassis/
> 

None Re: CREME_M1_GCR_Flux_Spectra.xlt  by Ivan Brilkov <Ivan Brilkov>,   26 Sep, 2014
Re: None Re: CREME_M1_GCR_Flux_Spectra.xlt (Hugh Evans)
Thank you very much, Hugh! Ivan On Mon, 17 Mar 2014 08:59:27 GMT, Hugh Evans wrote:
> Hi,
> 
> There are no macros in the file, so it should work with all recent
> versions of Excel.
> 
> The only cells to update are the Yellow ones (Element, year and minimum
> energy) on the G4-GPS sheet.
> 
> Note: energies below 10 MeV are not supported by the CREME-86 model on
> which the spreadsheet is based.
> 
> You can also obtain GCR spectra in G4-GPS format using SPENVIS (
> http://www.spenvis.oma.be ). This includes the more recent GCR models
> (ISO-15390, etc) as well as trapped and solar particle models.
> 
> Hugh

None The 10th Geant4 Space Users Workshop  by Svetlana Shasharina <Svetlana Shasharina>,   19 Feb, 2014
If this is an open event, could somebody post the URL please? Thanks, Sveta

None Re: The 10th Geant4 Space Users Workshop  by Makoto Asai <Makoto Asai>,   19 Feb, 2014
Re: None The 10th Geant4 Space Users Workshop (Svetlana Shasharina)
We are still finalizing the web pages.
URL will be announced as soon as it gets ready, along with
registration and abstract submission instructions.

Makoto

On 2/19/14 4:58 PM, "Svetlana Shasharina" <sveta@txcorp.com> wrote:

>
>*** Discussion title: Space Applications
>
>If this is an open event, could somebody post the URL please? Thanks,
>Sveta
>
>-------------------------------------------------------------
>Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or
>unsubscribe) at: 
>http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/99.html 


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Question differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   12 Feb, 2014
I was using gras with mulassis type of geometry (hollow sphere with a solid sphere inside) and am getting huge differences in TID (the ratios are not constant, though):

TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13

TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05

The inputs were generated using spenvis portal but I also ran gras 2.1 locally and confirmed that the resulting TIDs are huge.

Anybody can help me to interpret these differences?

Thanks, Sveta

None Re: differences in TIDs produced by gras and mulassis  by Laurent Desorgher <Laurent Desorgher>,   24 Feb, 2014
Re: Question differences in TIDs produced by gras and mulassis (Svetlana Shasharina)
Dear Sveta,

Could you explain more on the type of inputs you are using fort your different runs? Number of primaries, definition of geometry? Any normalisation?

Best regards

Laurent Desorgher

On Wed, 12 Feb 2014 21:47:27 GMT, Svetlana Shasharina wrote:

> I was using gras with mulassis type of geometry (hollow sphere with a
> solid sphere inside) and am getting huge differences in TID (the ratios
> are not constant, though):
> 
> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
> 
> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
> 
> The inputs were generated using spenvis portal but I also ran gras 2.1
> locally and confirmed that the resulting TIDs are huge.
> 
> Anybody can help me to interpret these differences?
> 
> Thanks, Sveta
> 

None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   25 Feb, 2014
Re: None Re: differences in TIDs produced by gras and mulassis (Laurent Desorgher)
Dear Laurent,
I think we resolved the problem (please see 
https://www.spenvis.oma.be/forum/viewtopic.php?f=16&t=288).  Looks like 
the command setUnit is not respected by gras (the result was the same 
when I used rad or Mev).  So in order to obtain a reasonable result, I 
used Mev and normalized the result by dividing it by (6.24e+10*mass 
[kg]) in order to get TID in rad.

Thanks,
Sveta

On 2/25/14 12:44 AM, Laurent Desorgher wrote:
>
> *** Discussion title: Space Applications
>
> Dear Sveta,
>
> Could you explain more on the type of inputs you are using fort your
> different runs? Number of primaries, definition of geometry? Any
> normalisation?
>
> Best regards
>
> Laurent Desorgher
>
> On Wed, 12 Feb 2014 21:47:27 GMT, Svetlana Shasharina wrote:
>
>> I was using gras with mulassis type of geometry (hollow sphere with a
>> solid sphere inside) and am getting huge differences in TID (the ratios
>> are not constant, though):
>>
>> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
>>
>> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
>>
>> The inputs were generated using spenvis portal but I also ran gras 2.1
>> locally and confirmed that the resulting TIDs are huge.
>>
>> Anybody can help me to interpret these differences?
>>
>> Thanks, Sveta
>>
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2.html
>

More Re: differences in TIDs produced by gras and mulassis  by Roger Byrd <Roger Byrd>,   05 Aug, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Svetlana Shasharina)
Dear Sveta,

I may have come upon another subtle issue with the dose normalization in GRAS.

I was trying to get consistent SPENVIS dose results in rads for simple spherical shells running in SHIELDOSE, MULASSIS, SSAT, and GRAS. As long as I made my shells large (>50 cm), the results from the first three tools were in agreement, including using shells versus slabs in MULASSIS.

When I started with GRAS, my answers were very odd, but I found your comment about areal densities, which resolved *almost* all the problems. That is, I can run MULASSIS and calculate MeV or dose, or I can run GRAS in MULASSIS input mode, where I calculate MeV/cm2 and rads and then apply your correction. All results agree.

However, if I run GRAS in its GDML input mode and define a spherical source that encloses my geometry, the dose and energy density I get are a factor of 4 higher than the other values from MULASSIS or GRAS/MULASSIS. Changing the sphere radius does not affect the normalization, only the statistics.

I suspect the difference is in the conversion from slabs to spheres, where other threads point out a similar normalization issue, but I'd like to be sure.

If it's correct to simply reduce the GRAS/GDML energies and doses by 4, then all four tools appear to give consistent results for all my test cases.

Thanks

On Tue, 25 Feb 2014 18:15:43 GMT, sveta wrote:

> Dear Laurent,
> I think we resolved the problem (please see 
> https://www.spenvis.oma.be/forum/viewtopic.php?f=16&t=288 (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288)).  Looks like 
> the command setUnit is not respected by gras (the result was the same 
> when I used rad or Mev).  So in order to obtain a reasonable result, I 
> used Mev and normalized the result by dividing it by (6.24e+10*mass 
> [kg]) in order to get TID in rad.
> 
> Thanks,
> Sveta
> 
> On 2/25/14 12:44 AM, Laurent Desorgher wrote:
> >
> > *** Discussion title: Space Applications
> >
> > Dear Sveta,
> >
> > Could you explain more on the type of inputs you are using fort your
> > different runs? Number of primaries, definition of geometry? Any
> > normalisation?
> >
> > Best regards
> >
> > Laurent Desorgher
> >
> > On Wed, 12 Feb 2014 21:47:27 GMT, Svetlana Shasharina wrote:
> >
> >> I was using gras with mulassis type of geometry (hollow sphere with a
> >> solid sphere inside) and am getting huge differences in TID (the ratios
> >> are not constant, though):
> >>
> >> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
> >>
> >> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
> >>
> >> The inputs were generated using spenvis portal but I also ran gras 2.1
> >> locally and confirmed that the resulting TIDs are huge.
> >>
> >> Anybody can help me to interpret these differences?
> >>
> >> Thanks, Sveta
> >>
> >
> > -------------------------------------------------------------
> > Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> > http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2.html
> >
> 

None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   05 Aug, 2015
Re: More Re: differences in TIDs produced by gras and mulassis (Roger Byrd)
Dear Roger,

The normalization problem appeared when I used GRAS through SPENVIS 
portal.  When I used GRAS itself, I could specify the units in the input 
.mac files without the need to change the data.

Couple of questions:

1.  Is this "exactly" 4?

2.  Can you add this line to your master .mac for GRAS:
/geometry/test/recursive_test

and see if your shapes do not intersect (even a tiny overlap can produce 
errors in Geant4)?

3.  Do you compile Geant4 and GRAS on your machine?  I used to have 
problems until I made sure that Geant4 version was geant4.9.6.p03.

Cheers,
Sveta



On 8/5/15 12:56 PM, Roger Byrd wrote:
>
> *** Discussion title: Space Applications
>
> Dear Sveta,
>
> I may have come upon another subtle issue with the dose normalization in
> GRAS.
>
> I was trying to get consistent SPENVIS dose results in rads for simple
> spherical shells running in SHIELDOSE, MULASSIS, SSAT, and GRAS. As long
> as I made my shells large (>50 cm), the results from the first three
> tools were in agreement, including using shells versus slabs in
> MULASSIS.
>
> When I started with GRAS, my answers were very odd, but I found your
> comment about areal densities, which resolved *almost* all the problems.
> That is, I can run MULASSIS and calculate MeV or dose, or I can run GRAS
> in MULASSIS input mode, where I calculate MeV/cm2 and rads and then
> apply your correction. All results agree.
>
> However, if I run GRAS in its GDML input mode and define a spherical
> source that encloses my geometry, the dose and energy density I get are
> a factor of 4 higher than the other values from MULASSIS or
> GRAS/MULASSIS. Changing the sphere radius does not affect the
> normalization, only the statistics.
>
> I suspect the difference is in the conversion from slabs to spheres,
> where other threads point out a similar normalization issue, but I'd
> like to be sure.
>
> If it's correct to simply reduce the GRAS/GDML energies and doses by 4,
> then all four tools appear to give consistent results for all my test
> cases.
>
> Thanks
>
> On Tue, 25 Feb 2014 18:15:43 GMT, sveta wrote:
>
>> Dear Laurent,
>> I think we resolved the problem (please see
>> https://www.spenvis.oma.be/forum/viewtopic.php?f=16&t=288 (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288) (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288)).  Looks like
>> the command setUnit is not respected by gras (the result was the same
>> when I used rad or Mev).  So in order to obtain a reasonable result, I
>> used Mev and normalized the result by dividing it by (6.24e+10*mass
>> [kg]) in order to get TID in rad.
>>
>> Thanks,
>> Sveta
>>
>> On 2/25/14 12:44 AM, Laurent Desorgher wrote:
>>>
>>> *** Discussion title: Space Applications
>>>
>>> Dear Sveta,
>>>
>>> Could you explain more on the type of inputs you are using fort your
>>> different runs? Number of primaries, definition of geometry? Any
>>> normalisation?
>>>
>>> Best regards
>>>
>>> Laurent Desorgher
>>>
>>> On Wed, 12 Feb 2014 21:47:27 GMT, Svetlana Shasharina wrote:
>>>
>>>> I was using gras with mulassis type of geometry (hollow sphere with a
>>>> solid sphere inside) and am getting huge differences in TID (the ratios
>>>> are not constant, though):
>>>>
>>>> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
>>>>
>>>> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
>>>>
>>>> The inputs were generated using spenvis portal but I also ran gras 2.1
>>>> locally and confirmed that the resulting TIDs are huge.
>>>>
>>>> Anybody can help me to interpret these differences?
>>>>
>>>> Thanks, Sveta
>>>>
>>>
>>> -------------------------------------------------------------
>>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
>>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2.html
>>>
>>
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1.html
>

More Re: differences in TIDs produced by gras and mulassis  by Roger Byrd <Roger Byrd>,   09 Aug, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Svetlana Shasharina)
Sveta,

As you have guessed, I'm running within SPENVIS, which probably renders the two latter questions moot. I'll revise my writeup to make that fact clear.

As to the renormalization factor in question 1, it's always 4 within statistics. For MULASSIS and GDML spheres, a typical dose ratio is 4.0099 +/- 0.0085.

Thanks, Roger

On Wed, 05 Aug 2015 19:29:13 GMT, Sveta wrote:

> Dear Roger,
> 
> The normalization problem appeared when I used GRAS through SPENVIS 
> portal.  When I used GRAS itself, I could specify the units in the input 
> .mac files without the need to change the data.
> 
> Couple of questions:
> 
> 1.  Is this "exactly" 4?
> 
> 2.  Can you add this line to your master .mac for GRAS:
> /geometry/test/recursive_test
> 
> and see if your shapes do not intersect (even a tiny overlap can produce 
> errors in Geant4)?
> 
> 3.  Do you compile Geant4 and GRAS on your machine?  I used to have 
> problems until I made sure that Geant4 version was geant4.9.6.p03.
> 
> Cheers,
> Sveta
> 
> On 8/5/15 12:56 PM, Roger Byrd wrote:
> >
> > *** Discussion title: Space Applications
> >
> > Dear Sveta,
> >
> > I may have come upon another subtle issue with the dose normalization in
> > GRAS.
> >
> > I was trying to get consistent SPENVIS dose results in rads for simple
> > spherical shells running in SHIELDOSE, MULASSIS, SSAT, and GRAS. As long
> > as I made my shells large (>50 cm), the results from the first three
> > tools were in agreement, including using shells versus slabs in
> > MULASSIS.
> >
> > When I started with GRAS, my answers were very odd, but I found your
> > comment about areal densities, which resolved *almost* all the problems.
> > That is, I can run MULASSIS and calculate MeV or dose, or I can run GRAS
> > in MULASSIS input mode, where I calculate MeV/cm2 and rads and then
> > apply your correction. All results agree.
> >
> > However, if I run GRAS in its GDML input mode and define a spherical
> > source that encloses my geometry, the dose and energy density I get are
> > a factor of 4 higher than the other values from MULASSIS or
> > GRAS/MULASSIS. Changing the sphere radius does not affect the
> > normalization, only the statistics.
> >
> > I suspect the difference is in the conversion from slabs to spheres,
> > where other threads point out a similar normalization issue, but I'd
> > like to be sure.
> >
> > If it's correct to simply reduce the GRAS/GDML energies and doses by 4,
> > then all four tools appear to give consistent results for all my test
> > cases.
> >
> > Thanks
> >
> > On Tue, 25 Feb 2014 18:15:43 GMT, sveta wrote:
> >
> >> Dear Laurent,
> >> I think we resolved the problem (please see
> >> https://www.spenvis.oma.be/forum/viewtopic.php?f=16&t=288 (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288) (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288) (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288)).  Looks like
> >> the command setUnit is not respected by gras (the result was the same
> >> when I used rad or Mev).  So in order to obtain a reasonable result, I
> >> used Mev and normalized the result by dividing it by (6.24e+10*mass
> >> [kg]) in order to get TID in rad.
> >>
> >> Thanks,
> >> Sveta
> >>
> >> On 2/25/14 12:44 AM, Laurent Desorgher wrote:
> >>>
> >>> *** Discussion title: Space Applications
> >>>
> >>> Dear Sveta,
> >>>
> >>> Could you explain more on the type of inputs you are using fort your
> >>> different runs? Number of primaries, definition of geometry? Any
> >>> normalisation?
> >>>
> >>> Best regards
> >>>
> >>> Laurent Desorgher
> >>>
> >>> On Wed, 12 Feb 2014 21:47:27 GMT, Svetlana Shasharina wrote:
> >>>
> >>>> I was using gras with mulassis type of geometry (hollow sphere with a
> >>>> solid sphere inside) and am getting huge differences in TID (the ratios
> >>>> are not constant, though):
> >>>>
> >>>> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
> >>>>
> >>>> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
> >>>>
> >>>> The inputs were generated using spenvis portal but I also ran gras 2.1
> >>>> locally and confirmed that the resulting TIDs are huge.
> >>>>
> >>>> Anybody can help me to interpret these differences?
> >>>>
> >>>> Thanks, Sveta
> >>>>
> >>>
> >>> -------------------------------------------------------------
> >>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> >>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2.html
> >>>
> >>
> >
> > -------------------------------------------------------------
> > Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> > http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1.html
> >
> 

None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   09 Aug, 2015
Re: More Re: differences in TIDs produced by gras and mulassis (Roger Byrd)
Hi Roger,

I think that taking into account real geometry can result in the 4 
factor.  I would also post the results as a question on the Spenvis 
forum.  neophytos.messios@oma.be was extremely helpful when I had 
technical questions about spenvis.

Cheers,
Sveta

On 8/9/15 11:28 AM, Roger Byrd wrote:
>
> *** Discussion title: Space Applications
>
> Sveta,
>
> As you have guessed, I'm running within SPENVIS, which probably renders
> the two latter questions moot. I'll revise my writeup to make that fact
> clear.
>
> As to the renormalization factor in question 1, it's always 4 within
> statistics. For MULASSIS and GDML spheres, a typical dose ratio is
> 4.0099 +/- 0.0085.
>
> Thanks, Roger
>
> On Wed, 05 Aug 2015 19:29:13 GMT, Sveta wrote:
>
>> Dear Roger,
>>
>> The normalization problem appeared when I used GRAS through SPENVIS
>> portal.  When I used GRAS itself, I could specify the units in the input
>> .mac files without the need to change the data.
>>
>> Couple of questions:
>>
>> 1.  Is this "exactly" 4?
>>
>> 2.  Can you add this line to your master .mac for GRAS:
>> /geometry/test/recursive_test
>>
>> and see if your shapes do not intersect (even a tiny overlap can produce
>> errors in Geant4)?
>>
>> 3.  Do you compile Geant4 and GRAS on your machine?  I used to have
>> problems until I made sure that Geant4 version was geant4.9.6.p03.
>>
>> Cheers,
>> Sveta
>>
>> On 8/5/15 12:56 PM, Roger Byrd wrote:
>>>
>>> *** Discussion title: Space Applications
>>>
>>> Dear Sveta,
>>>
>>> I may have come upon another subtle issue with the dose normalization in
>>> GRAS.
>>>
>>> I was trying to get consistent SPENVIS dose results in rads for simple
>>> spherical shells running in SHIELDOSE, MULASSIS, SSAT, and GRAS. As long
>>> as I made my shells large (>50 cm), the results from the first three
>>> tools were in agreement, including using shells versus slabs in
>>> MULASSIS.
>>>
>>> When I started with GRAS, my answers were very odd, but I found your
>>> comment about areal densities, which resolved *almost* all the problems.
>>> That is, I can run MULASSIS and calculate MeV or dose, or I can run GRAS
>>> in MULASSIS input mode, where I calculate MeV/cm2 and rads and then
>>> apply your correction. All results agree.
>>>
>>> However, if I run GRAS in its GDML input mode and define a spherical
>>> source that encloses my geometry, the dose and energy density I get are
>>> a factor of 4 higher than the other values from MULASSIS or
>>> GRAS/MULASSIS. Changing the sphere radius does not affect the
>>> normalization, only the statistics.
>>>
>>> I suspect the difference is in the conversion from slabs to spheres,
>>> where other threads point out a similar normalization issue, but I'd
>>> like to be sure.
>>>
>>> If it's correct to simply reduce the GRAS/GDML energies and doses by 4,
>>> then all four tools appear to give consistent results for all my test
>>> cases.
>>>
>>> Thanks
>>>
>>> On Tue, 25 Feb 2014 18:15:43 GMT, sveta wrote:
>>>
>>>> Dear Laurent,
>>>> I think we resolved the problem (please see
>>>> https://www.spenvis.oma.be/forum/viewtopic.php?f=16&t=288 (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288) (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288) (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288) (https://www.spenvis.oma.be/forum/viewtopic.php?f=16&amp;t=288)).  Looks like
>>>> the command setUnit is not respected by gras (the result was the same
>>>> when I used rad or Mev).  So in order to obtain a reasonable result, I
>>>> used Mev and normalized the result by dividing it by (6.24e+10*mass
>>>> [kg]) in order to get TID in rad.
>>>>
>>>> Thanks,
>>>> Sveta
>>>>
>>>> On 2/25/14 12:44 AM, Laurent Desorgher wrote:
>>>>>
>>>>> *** Discussion title: Space Applications
>>>>>
>>>>> Dear Sveta,
>>>>>
>>>>> Could you explain more on the type of inputs you are using fort your
>>>>> different runs? Number of primaries, definition of geometry? Any
>>>>> normalisation?
>>>>>
>>>>> Best regards
>>>>>
>>>>> Laurent Desorgher
>>>>>
>>>>> On Wed, 12 Feb 2014 21:47:27 GMT, Svetlana Shasharina wrote:
>>>>>
>>>>>> I was using gras with mulassis type of geometry (hollow sphere with a
>>>>>> solid sphere inside) and am getting huge differences in TID (the ratios
>>>>>> are not constant, though):
>>>>>>
>>>>>> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
>>>>>>
>>>>>> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
>>>>>>
>>>>>> The inputs were generated using spenvis portal but I also ran gras 2.1
>>>>>> locally and confirmed that the resulting TIDs are huge.
>>>>>>
>>>>>> Anybody can help me to interpret these differences?
>>>>>>
>>>>>> Thanks, Sveta
>>>>>>
>>>>>
>>>>> -------------------------------------------------------------
>>>>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
>>>>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2.html
>>>>>
>>>>
>>>
>>> -------------------------------------------------------------
>>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
>>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1.html
>>>
>>
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1/1/1.html
>

None Re: differences in TIDs produced by gras and mulassis  by John Allison <John Allison>,   10 Aug, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Svetlana Shasharina)
I'm not an astronomer but I once got caught by a factor of 4. In space physics fluxes are usually quoted in units of particles per steradian per unit time per unit area. So for a flux of F there are F/4 particles hitting a surface per unit time per unit area. The factor of 4 comes from integrating over a hemisphere.

None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   10 Aug, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (John Allison)
It would be nice to nail this down and know what we are calculating:-)
Sveta

On 8/10/15 1:38 AM, John Allison wrote:
>
> *** Discussion title: Space Applications
>
> I'm not an astronomer but I once got caught by a factor of 4. In space
> physics fluxes are usually quoted in units of particles per steradian
> per unit time per unit area. So for a flux of F there are F/4 particles
> hitting a surface per unit time per unit area. The factor of 4 comes
> from integrating over a hemisphere.
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1/1/1/1/1.html
>

None Re: differences in TIDs produced by gras and mulassis  by Hugh Evans <Hugh Evans>,   12 Aug, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Svetlana Shasharina)
The factor of 4 is due to the automated conversion within SPENVIS/Mulassis and GRAS from the omni-directional environmental FLUX to the Monte-Carlo CURRENT. Within GRAS, this is not always applied, due to the complex variations of the geometry definition with the external sources. For Mulassis, SPENVIS automatically includes the factor of 4 in the GPS macro file:
/control/alias NORM_FACTOR_ANGULAR " 2.500000E-01 "
This factor of 4 is a normal part of the normalisation process. I direct you to the SHIELDOSE original publication that outlines the normalisation process from omni-directional flux to current:

Seltzer, S.M., "Electron, Electron-Bremsstrahlung and Proton Depth-Dose Data for Space-Shielding Applications," Nuclear Science, IEEE Transactions on , vol.26, no.6, pp.4896,4904, Dec. 1979 doi: 10.1109/TNS.1979.4330247 keywords: {Aircraft manufacture;Aluminum;Detectors;Electron emission;Monte Carlo methods;Production;Protons;Satellites;Slabs;Solids}, URL: IEEE Link
In particular, see the "Initial and Boundary Conditions" section, and equation (5):
Phi4Pi = 2 Phi2Pi = 4 J
None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   18 Sep, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Hugh Evans)
Dear Hugh,

I am not sure how to interpret this information.
If I have a GRAS simulation calculating TID using these settings:

/control/alias  NORM_FACTOR_ANGULAR "   2.500000E-01 "
/gras/analysis/setNormalisationType FLUENCE
/gras/analysis/setSourceFluence {NORM_FACTOR} 1/cm2
/gras/analysis/setSourceFluenceType FLUX
/gras/analysis/setSourceSurfaceType AUTO

Should I do anything with calculated dose or not?
Thanks,
Sveta


On 8/12/15 2:24 AM, Hugh Evans wrote:
>
> *** Discussion title: Space Applications
>
> The factor of 4 is due to the automated conversion within
> SPENVIS/Mulassis and GRAS from the omni-directional environmental FLUX
> to the Monte-Carlo CURRENT. Within GRAS, this is not always applied, due
> to the complex variations of the geometry definition with the external
> sources. For Mulassis, SPENVIS automatically includes the factor of 4 in
> the GPS macro file:
>
>      /control/alias NORM_FACTOR_ANGULAR " 2.500000E-01 "
>
> This factor of 4 is a normal part of the normalisation process. I direct
> you to the SHIELDOSE original publication that outlines the
> normalisation process from omni-directional flux to current:
>
>      Seltzer, S.M., "Electron, Electron-Bremsstrahlung and Proton
>      Depth-Dose Data for Space-Shielding Applications," Nuclear
>      Science, IEEE Transactions on , vol.26, no.6, pp.4896,4904, Dec.
>      1979 doi: 10.1109/TNS.1979.4330247 keywords: {Aircraft
>      manufacture;Aluminum;Detectors;Electron emission;Monte Carlo
>      methods;Production;Protons;Satellites;Slabs;Solids}, URL: IEEE
>      Link (http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4330247&isnumber=4330205)
>
> In particular, see the "Initial and Boundary Conditions" section, and
> equation (5):
>
>      Phi 4Pi = 2 Phi 2Pi = 4 J
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1/1/1/1/1/1/1.html
>

None Re: differences in TIDs produced by gras and mulassis  by Hugh Evans <Hugh Evans>,   12 Aug, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Hugh Evans)
I would also direct you to the SPENVIS help pages, which might help to clarify the situation.

https://www.spenvis.oma.be/help/models/g4_source_new.html#angular

Regards, Hugh

None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   29 Sep, 2015
Re: None Re: differences in TIDs produced by gras and mulassis (Hugh Evans)
So flux is 4 times bigger than current for our (isotropic 
omnidirectional) case. Spenvis files use FLUX (not CURRENT) and 
NORM_FACTOR_ANGULAR = 0.25 as a reflection of this. This would imply 
that the results are multiplied by this factor.

I verified that if I use CURRENT instead of FLUX (without changing 
NORM_FACTOR_ANGULAR) I get tid 4 times bigger.

So one should expect that if I use CURRENT, one should set 
NORM_FACTOR_ANGULAR = 1? I tried doing this and the result was 16 times 
bigger compared to the case FLUX and NORM_FACTOR_ANGULAR = 0.25. So it 
looks like that the result is DIVIDED by NORM_FACTOR_ANGULAR rather then 
being multiplied.

Is it possible that NORM_FACTOR_ANGULAR is used incorrectly (the results 
are DIVIDED by it instead of being multiplied by it)?

That would mean that one should set it:

FLUX: NORM_FACTOR_ANGULAR = 4
CURRENT: NORM_FACTOR_ANGULAR = 1

I used these settings in GRAS runs and got the identical results for 
tids for these.

Thanks,
Sveta

On 8/12/15 3:06 AM, Hugh Evans wrote:
>
> *** Discussion title: Space Applications
>
> I would also direct you to the SPENVIS help pages, which might help to
> clarify the situation.
>
> https://www.spenvis.oma.be/help/models/g4_source_new.html#angular
>
> Regards, Hugh
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98/2/1/1/1/1/1/1/1/1/1.html
>

None Re: differences in TIDs produced by gras and mulassis  by Svetlana Shasharina <Svetlana Shasharina>,   12 Feb, 2014
Re: Question differences in TIDs produced by gras and mulassis (Svetlana Shasharina)
Meant to say that I have huge differences between gras with mulassis 
geometry and mulassis.
Thanks,
Sveta

On 2/12/14 2:47 PM, Svetlana Shasharina wrote:
>
> *** Discussion title: Space Applications
>
> I was using gras with mulassis type of geometry (hollow sphere with a
> solid sphere inside) and am getting huge differences in TID (the ratios
> are not constant, though):
>
> TID Al (gras) TID Cu (gras) 1.07E+15 1.01E+13
>
> TID Al (mulassis) TID Cu (mulassis) 5.70E+06 1.40E+05
>
> The inputs were generated using spenvis portal but I also ran gras 2.1
> locally and confirmed that the resulting TIDs are huge.
>
> Anybody can help me to interpret these differences?
>
> Thanks, Sveta
>
> -------------------------------------------------------------
> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/98.html
>

Question use integral particle flux as input  by Svetlana Shasharina <Svetlana Shasharina>,   28 Jan, 2014
Hi, I see that I need to set up my source using the shape of radiation, angular distribution and the energy spectrum. Quite often I see that only integral omnidirectional flux is available as data. How one woudl create a G4 particle source from this? I can assume isotropy.

Thanks, Sveta

Question Can we simulate the imaging process of Wolter-I type telescope?  by <zhaodh@bao.ac.cn>,   26 Aug, 2013
Hi everyone,

Can we simulate the imaging process of Wolter-I type X-ray ( a few keV) telescope and save the image using Geant4?

If we can, how to do it? Since there is no total internal reflection for X-ray in Geant4.

Looking forward to your reply. Thank you and best regards,

D.H Z

Question GPS interpolation  by Wolfgang Mai <Wolfgang Mai>,   25 Jun, 2013
Dear colleagues,

do you know how the general particle source is interpolating arbitrary spectra?

I was using GRAS 3.1 with an SPENVIS generated macro with an diff. electron spectrum (AE-8MAX, GEO), which looked like this:

/gps/particle e-
/gps/ene/type Arb
/gps/hist/type arb
/gps/hist/point 4.000000E-02 1.138400E+10
/gps/hist/point 1.000000E-01 5.653800E+09
/gps/hist/point 2.000000E-01 5.623300E+08
/gps/hist/point 3.000000E-01 1.717600E+08
/gps/hist/point 4.000000E-01 8.587400E+07
/gps/hist/point 5.000000E-01 5.386000E+07
/gps/hist/point 6.000000E-01 3.011800E+07
/gps/hist/point 7.000000E-01 2.467300E+07
/gps/hist/point 8.000000E-01 2.042700E+07
/gps/hist/point 1.000000E+00 1.383600E+07
/gps/hist/point 1.250000E+00 8.481900E+06
/gps/hist/point 1.500000E+00 4.907300E+06
/gps/hist/point 1.750000E+00 2.598900E+06
/gps/hist/point 2.000000E+00 1.649900E+06
/gps/hist/point 2.250000E+00 9.743300E+05
/gps/hist/point 2.500000E+00 4.355700E+05
/gps/hist/point 2.750000E+00 1.797200E+05
/gps/hist/point 3.000000E+00 8.610400E+04
/gps/hist/point 3.250000E+00 4.061000E+04
/gps/hist/point 3.500000E+00 2.145000E+04
/gps/hist/point 3.750000E+00 1.119400E+04
/gps/hist/point 4.000000E+00 4.665900E+03
/gps/hist/point 4.250000E+00 1.943400E+03
/gps/hist/point 4.500000E+00 8.365100E+02
/gps/hist/point 4.750000E+00 3.363000E+02
/gps/hist/point 5.000000E+00 5.920500E+01
/gps/hist/point 5.500000E+00 3.613200E+00
/gps/hist/point 6.000000E+00 0.000000E+00
#/gps/hist/point 6.500000E+00 0.000000E+00
#/gps/hist/point 7.000000E+00 0.000000E+00
/gps/hist/inter Lin
/gps/ang/type cos
/gps/ang/maxtheta 90.00 deg
/gps/pos/type Surface
/gps/shape Sphere
/gps/pos/centre 0.0000E+00 0.0000E+00 0.0000E+00 mm
/gps/pos/radius 5.100000E+00 mm

#
#Normalisation
#
/gras/analysis/setNormalisationType FLUENCE
/gras/analysis/setSourceFluence 2.0767E+17 cm-2

Now what I did was cutting the first value of the spectrum and changing the fluence value in order to get a better statistic, as these particles don't contribute remarkable to my dose measurement. The macro then looked like this:

...
/gps/hist/type arb
#/gps/hist/point 4.000000E-02 1.138400E+10
/gps/hist/point 1.000000E-01 5.653800E+09
...
/gras/analysis/setSourceFluence 4.6473E+16 cm-2

The strange thing is now, that the measured dose is only half the value of the first one, although these low energy electrons don't contribute.
After that I measured the fluence of these sources I saw, that there are much more electrons over 0.1 MeV in the first case than in the second. It seems, that gps distributes the particles in a different way as they really are distributed.

Does anyone know about this problem?

Thank you in advance
Wolfgang

Question Problem building GRAS code  by Leonardo Ghizoni <Leonardo Ghizoni>,   24 May, 2013
Hello,

I've downloaded the GRAS code to perform Geant4 space applications simulations. When building the code, I ran the command with cmake:

lghizoni@EQSAPhysics:~/Geant4/Gras-build$ cmake -DCMAKE_INSTALL_PREFIX=/home/lghizoni/Geant4/geant4.9.6-install/ -DWITH_ROOT=ON -DSTATIC_BUILD=ON -DGRAS_INSTALL_PREFIX=/home/lghizoni/Geant4/Gras-build/ /home/lghizoni/Geant4/Gras

That went OK, no errors! But then I ran 'make', and got the following error:

lghizoni@EQSAPhysics:~/Geant4/Gras-build$ make
Scanning dependencies of target gras_lib
[  0%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASNIELAnalysisModuleMessenger.cc.o
[  1%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASAnalysisManager.cc.o
[  1%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASFluenceAnalysisModule.cc.o
[  1%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASNIELCurveSetGaAsSummers.cc.o
[  2%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASChargeCollectionAnalysisModule.cc.o
[  2%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASEqDoseAnalysisModule.cc.o
[  3%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASNIELCurveSet_JPL_NRL_NASA_InP.cc.o
[  3%] Building CXX object CMakeFiles/gras_lib.dir/source/analysis/src/GRASActivationAnalysisModule.cc.o
/home/lghizoni/Geant4/Gras/source/analysis/src/GRASActivationAnalysisModule.cc: In member function virtual void GRASActivationAnalysisModule::EndOfRun(const GRASInfo*):
/home/lghizoni/Geant4/Gras/source/analysis/src/GRASActivationAnalysisModule.cc:127:73: error: cannot convert std::map<CLHEP::Hep3Vector, CLHEP::Hep2Vector>* to std::map<CLHEP::Hep3Vector, double>* in initialization
/home/lghizoni/Geant4/Gras/source/analysis/src/GRASActivationAnalysisModule.cc: In member function virtual void GRASActivationAnalysisModule::PrintCSVFile(const GRASInfo*, SpenvisCSVCollection*):
/home/lghizoni/Geant4/Gras/source/analysis/src/GRASActivationAnalysisModule.cc:223:73: error: cannot convert std::map<CLHEP::Hep3Vector, CLHEP::Hep2Vector>* to std::map<CLHEP::Hep3Vector, double>* in initialization
In file included from /home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/G4PhysicalConstants.hh:27:0,
                 from /home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/globals.hh:70,
                 from /home/lghizoni/Geant4/Gras/source/analysis/include/GRASActivationAnalysisModule.hh:38,
                 from /home/lghizoni/Geant4/Gras/source/analysis/src/GRASActivationAnalysisModule.cc:35:
/home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/CLHEP/Units/PhysicalConstants.h: At global scope:
/home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/CLHEP/Units/PhysicalConstants.h:79:21: warning: CLHEP::electron_charge defined but not used [-Wunused-variable]
In file included from /home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/Randomize.hh:32:0,
                 from /home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/G4SteppingManager.hh:62,
                 from /home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/G4TrackingManager.hh:56,
                 from /home/lghizoni/Geant4/Gras/source/global/include/GRASInfo.hh:42,
                 from /home/lghizoni/Geant4/Gras/source/analysis/src/GRASActivationAnalysisModule.cc:39:
/home/lghizoni/Geant4/geant4.9.6-install/include/Geant4/CLHEP/Random/Randomize.h:59:12: warning: CLHEP::HepRandomGenActive defined but not used [-Wunused-variable]
make[2]: *** [CMakeFiles/gras_lib.dir/source/analysis/src/GRASActivationAnalysisModule.cc.o] Error 1
make[1]: *** [CMakeFiles/gras_lib.dir/all] Error 2
make: *** [all] Error 2

Can someone help me?? I just don't know what to fix.

Thanks a lot

Leonardo.

Idea Re: Problem building GRAS code  by Vladimir Ivanchenko <Vladimir Ivanchenko>,   27 May, 2013
Re: Question Problem building GRAS code (Leonardo Ghizoni)
Hello,

This kind of problems likely connect with not coherent set of libraries used: CLHEP, Geant4, and GRAS. If you are taken the most recent referent tag of GRAS 3.1 than you need Geant4 9.6p01 and CLHEP 2.1.3.1

If you are using this version of Geant4 you may also disable external installation of CLHEP - CLHEP_BASE_DIR environment variable should not be defined. In that case CLHEP classes from Geant4 distribution will be used that guarantee coherence.

VI

None Re: Problem building GRAS code  by Paul Nicholas Colin Gloster <Paul Nicholas Colin Gloster>,   24 May, 2013
Re: Question Problem building GRAS code (Leonardo Ghizoni)
Dear Leonardo Ghizoni,

How did you get a copy of GRAS? I had applied for it years before you,
and I still do not have a copy.

Yours sincerely,
Colin Paul Gloster

None Re: Problem building GRAS code  by Leonardo Ghizoni <Leonardo Ghizoni>,   24 May, 2013
Re: None Re: Problem building GRAS code (Paul Nicholas Colin Gloster)
Dear Colin,

In the GRAS page (http://space-env.esa.int/index.php/geant4-radiation-analysis-for-space.html) it is said that you'll have access to the code upon registration. There, you have to register all your data, including the main reason for the request. Some weeks later I had an answer with a login and a password to access the code. (Actually, I had to ask for the code a couple of times).

Best regards.

Leonardo.

Question Please, tell me any example   by Batom <Batom>,   03 May, 2013
Dear

Please, advise me any example for how to use the function ComputeSolid in the Parameterisation class?

Regards

Question Simulate Total Ionizing Dose and Single Event Effect  by Leonardo Ghizoni <Leonardo Ghizoni>,   09 Apr, 2013
Hello,

I'm new with Geant4, and I'm trying to build a simulation to calculate the total ionizing dose and some single event effects on components of a satellite.

I studied a lot the GPS Class, but I still don't know where to begin with...

I also already have my geometry complete and was able to build it with GPS...

Can someone help how to begin with and maybe have some plots too??

Thanks a lot.

Best regards.

None Re: Simulate Total Ionizing Dose and Single Event Effect  by Hugh Evans <Hugh Evans>,   10 Apr, 2013
Re: Question Simulate Total Ionizing Dose and Single Event Effect (Leonardo Ghizoni)
Hello Leonardo,

As you are considering the use of the GPS for space scenarios, (if you are 
not already aware) I would recommend that you look at the SPENVIS site (
www.spenvis.oma.be). This site has integrated the Mulassis, GRAS, GEMAT, 
and SSAT Geant4 applications into a web based GUI that is linked with 
various space environment radiation models (AP8/AE8/ISO 15390/PSYCHIC, 
etc. etc. etc). Part of the integration of these Geant4 applications is 
the production of a macro file that includes the GPS commands to set up a 
space based environment in the simulation. It's a good starting point for 
examples.

Regards
Hugh




From:
"Leonardo Ghizoni" <leonardo.ghizoni@gmail.com>
To:
space_app-g4hn@slac.stanford.edu, 
Date:
09/04/2013 21:46
Subject:
Simulate Total Ionizing Dose and Single Event Effect




*** Discussion title: Space Applications

Hello,

I'm new with Geant4, and I'm trying to build a simulation to calculate
the total ionizing dose and some single event effects on components of a
satellite.

I studied a lot the GPS Class, but I still don't know where to begin
with...

I also already have my geometry complete and was able to build it with
GPS...

Can someone help how to begin with and maybe have some plots too??

Thanks a lot.

Best regards.

-------------------------------------------------------------
Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or 
unsubscribe) at: 
http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/92.html 



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None Re: Simulate Total Ionizing Dose and Single Event Effect  by Leonardo Ghizoni <Leonardo Ghizoni>,   10 Apr, 2013
Re: None Re: Simulate Total Ionizing Dose and Single Event Effect (Hugh Evans)
Thanks a lot Hugh,

I know about Spenvis, but wasn't aware of the packages. I'll be looking for it.

Best regards.

Leonardo.

None RE: Simulate Total Ionizing Dose and Single Event Effect  by Susanna <Susanna>,   09 Apr, 2013
Re: Question Simulate Total Ionizing Dose and Single Event Effect (Leonardo Ghizoni)
Dear Leonardo,

my suggestion is to start from the extended example
eventgenerator/exgps

This example shows how to use the GPS.

Cheers
Susanna

Dr. Susanna Guatelli
Centre for Medical Radiation Physics
School of Physics
University of Wollongong, NSW 2522
Australia,
Email: susanna@uow.edu.au
Phone: +61 2 4221 4374
Fax +61-2-42214955

2nd Geant4 School and Monte Carlo Workshop, 19-24 April 2013
http://www.uow.edu.au/eng/phys/cmrp/UOW135963.html
________________________________________
From: Leonardo Ghizoni [leonardo.ghizoni@gmail.com]
Sent: 10 April 2013 05:45
To: space_app-g4hn@slac.stanford.edu
Subject: Simulate Total Ionizing Dose and Single Event Effect

*** Discussion title: Space Applications

Hello,

I'm new with Geant4, and I'm trying to build a simulation to calculate
the total ionizing dose and some single event effects on components of a
satellite.

I studied a lot the GPS Class, but I still don't know where to begin
with...

I also already have my geometry complete and was able to build it with
GPS...

Can someone help how to begin with and maybe have some plots too??

Thanks a lot.

Best regards.

-------------------------------------------------------------
Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
http://hypernews.slac.stanford.edu/HyperNews/geant4/get/space_app/92.html
None Re: RE: Simulate Total Ionizing Dose and Single Event Effect  by Leonardo Ghizoni <Leonardo Ghizoni>,   10 Apr, 2013
Re: None RE: Simulate Total Ionizing Dose and Single Event Effect (Susanna)
Thank you very much Susanna!

I'll be studying the extended example for the GPS...

Best regards.

Leonardo.

None Sector Shilding Analysis Tool installation  by T Ergin <T Ergin>,   10 Feb, 2013
Hi, 

I've recently downloaded the latest source code of SSAT from
     http://reat.space.qinetiq.com/ssat/
I have also installed Geant4 with the GDML option set to ON. 

But the ssat_env.csh script is not working, because the variable GDMLTOP is not set and it is not clear what directory it should point to. 

When I look into the what the script is doing with GDMLTOP is that is goes into the subdirectories of this package that GDMLTOP is supposed to point at. But it is not clear where exactly or what package exactly this variable must point at. In the directory structure of the installed Geant4, it doesnt fit anywhere. Even the latest version of GDML from the Geant4 web site does not have such a subdirectory structure. 

Would you please let me know where exactly I should set this variable? 


 Thanks.

    T.
None Trouble with MULASSIS install  by Brian Evans <Brian Evans>,   18 Sep, 2012
Hi All,

I'll admit I'm a complete novice when it comes to building applications with Geant4, so please forgive me if I'm missing something obvious.

I trying to build MULASSIS 1.23, with Geant4 9.5 on 64-bit RedHat Enterprise Linux 6, but I keep running into errors. For starters, I've successfully built CLHEP 2.1.1.0, XercesC 3.1.1, Geant4 9.5, and GRAS 3.1, and installed each in their own directory in /opt/local.

I've unpacked the MULASSIS tar file in /tmp/swbuild, which is also where the source for each of the previous packages are located as well (also each in their own directory).

Now, I followed instructions in some other posts for setting up environment variables, and it seems the most important for MULASSIS is G4INSTALL, which I've set to /opt/local/geant4.

So, the errors: When I run "gmake" from the MULASSIS source directory, I get an error saying it can't find files in the "config" dir, which indeed does not exist in /opt/local/geant4. But it does exist in the geant4 source dir, so the error above seems to indicate it's looking for the geant4 source files, not the install directory, which seems at odds with the instructions I got to set G4INSTALL to point to the install dir.

Any idea what I'm doing wrong? I'd be glad to provide any further information if needed.

Thanks in advance for any assistance!

Question Simulating deep space radiation environment and normalization of the results  by Ali Ebrahimi <Ali Ebrahimi>,   08 Aug, 2012
Hello,

I would to simulate deep space radiation environment (GCR+SPE) using GPS for my application. I have got GCR proton flux from CREME and wrote the following macro for GPS and want to know if it is correct:

/gps/particle proton /gps/ene/type Arb /gps/hist/type arb /gps/hist/point 1.0023 0.0055595 /gps/hist/point 1.01623 0.023156 ... /gps/hist/point 100000 5.8474E-05

/gps/hist/inter Log

/gps/pos/type Surface /gps/pos/shape Sphere /gps/pos/centre 0. 0. 0. mm /gps/pos/radius 20. m

/gps/ang/type cos /gps/ang/mintheta 0. deg /gps/ang/maxtheta 90. deg

If it is correct, who can I normalize it? I have seen a couple of of other questions regarding normalizations and saw the files on http://geant4.in2p3.fr/2007/prog/prog.htm but it is still not clear to me in particular since I'm using arbitrary type . I would appreciate it if you could please elaborate on this or give a reference so I can read myself.

Also, from the previous topics in the space category and from GPS examples I learned that it is possible to have several particle source and simulate SPE at the same time. To simulate SPE, say the worst case, should I do it like GCR with arbitrary types? If yes is there a source for flux data?

Thank you very much in advance, Ali

None How to get Primary Particle Energy ?  by Mehmet <Mehmet>,   02 Jul, 2012
Dear all,

It is probably a very simple question, but I could not figure it out although I have been searching for several hours. Basically, I would like to get the primary particle's (say proton) energy, generated using GPS, at the time of injection and print it out with the information of the secondary (say muon). I would appreciate if anyone could tell me how to do or at least direct me to location with example.

Thank you, Mehmet

Feedback Re: How to get Primary Particle Energy ?  by Neil Fazel <Neil Fazel>,   02 Jul, 2012
Re: None How to get Primary Particle Energy ? (Mehmet)
On Mon, 02 Jul 2012 12:42:39 GMT, Mehmet wrote:

> I would like to get the primary particle's (say proton) energy, generated using
> GPS, at the time of injection..

Can't you just use G4GeneralParticleSource::GetParticleEnergy() to get total initial energy?

Neil

None Re: How to get Primary Particle Energy ?  by John Allison <John Allison>,   02 Jul, 2012
Re: None How to get Primary Particle Energy ? (Mehmet)
In your event action:

  G4PrimaryVertex* primaryVertex = event->GetPrimaryVertex();
  G4PrimaryParticle* primaryParticle = primaryVertex->GetPrimary();
  G4double ke = primaryParticle->GetKineticEnergy();

Feedback Re: How to get Primary Particle Energy ?  by Mehmet <Mehmet>,   03 Jul, 2012
Re: None Re: How to get Primary Particle Energy ? (John Allison)
Thank you John and Neil for the responses. I could not make Neil's suggestion

G4GeneralParticleSource::GetParticleEnergy()

work due to my lack of Geant4 knowledge. Instead, I have added a couple of more lines to Johns's suggestion since G4double ke = primaryParticle->GetKineticEnergy(); gave error. Pasted below is part of the code that works:

G4PrimaryVertex* primaryVertex = evt->GetPrimaryVertex();

G4PrimaryParticle* primaryParticle = primaryVertex->GetPrimary();

G4double px = primaryParticle->GetPx();

G4double py = primaryParticle->GetPy();

G4double pz = primaryParticle->GetPz();

G4double mass = primaryParticle->GetMass();

G4double mom2=px*px+py*py+pz*pz;

G4double E=sqrt(mom2+mass*mass);

This may not be the shortest and best way to get what I want, but it seems to work.

Thank you again for the help, Mehmet

On Mon, 02 Jul 2012 13:25:48 GMT, John Allison wrote:

> In your event action:
> 
>   G4PrimaryVertex* primaryVertex = event->GetPrimaryVertex();
>   G4PrimaryParticle* primaryParticle = primaryVertex->GetPrimary();
>   G4double ke = primaryParticle->GetKineticEnergy();
> 

Feedback Re: How to get Primary Particle Energy ?  by Michael H. Kelsey <Michael H. Kelsey>,   03 Jul, 2012
Re: Feedback Re: How to get Primary Particle Energy ? (Mehmet)
On Tue, 03 Jul 2012 11:56:10 GMT, Mehmet wrote:
> Thank you John and Neil for the responses. I could not make Neil's
> suggestion
> 
> G4GeneralParticleSource::GetParticleEnergy()
> 
> work due to my lack of Geant4 knowledge. Instead, I have added a couple
> of more lines to Johns's suggestion since G4double ke =
> primaryParticle->GetKineticEnergy(); gave error.

That member function was added in 9.5; it's not available in 9.4 (I have the same problem in my own code, which has to be 9.4-compatible).

> Pasted below is part of the code that works:
> 
> G4PrimaryVertex* primaryVertex = evt->GetPrimaryVertex();
> G4PrimaryParticle* primaryParticle = primaryVertex->GetPrimary();
> G4double px = primaryParticle->GetPx();
> G4double py = primaryParticle->GetPy();
> G4double pz = primaryParticle->GetPz();
> G4double mass = primaryParticle->GetMass();
> G4double mom2=px*px+py*py+pz*pz;
> G4double E=sqrt(mom2+mass*mass);
> 
> This may not be the shortest and best way to get what I want, but it
> seems to work.

In my 9.4-based code, I use:

  // FIXME:  In GEANT4 9.4, GetKineticEnergy() doesn't exist, must compute
  // e1Prim = aPrimary->GetKineticEnergy();
  e1Prim = (std::sqrt(aPrimary->GetMomentum().mag2()
                      + aPrimary->GetMass()*aPrimary->GetMass())
            - aPrimary->GetMass());

Notice that you can use GetMomentum() to get the three-momentum, instead of having to access the components individually.

Also, note that your "E" is, of course, the total energy of the particle, not just its kinetic energy. For particle physics, that's right, but I've learned that the fixed-target/nuclear community tends to use Ekin (= E-m) rather than E.

  -- Michael Kelsey

Question Simulating and calculating Geometric Factors in GEANT4  by Bruno Morgado <Bruno Morgado>,   26 Jun, 2012
Hello,
I'm trying to calculate the "real" Geometric Factor (GF) of an instrument in Geant, but I'm having some problems with the results.

My macro file is:
# Set GPS spherical source
/gps/particle e-			# particle type
/gps/pos/type Surface
/gps/pos/shape Sphere
/gps/centre 0 0 0 m			# source centre
/gps/pos/radius 10 cm
/gps/ang/type cos
/gps/ene/mono 52. keV
/run/beamOn 200000000

And I finish calculating the GF with:
double geometryFactor(double numberDetectedParticles, double numberEmitedParticles, const double sourceRadius) {
    return ((8 * numberDetectedParticles * pow(TMath::Pi(), 2) * pow(sourceRadius, 2)) / numberEmitedParticles);
}

Still, like I said the results don't seem to add up. Can you direct me to some place where I can check if these are the correct calculations or if there is some mistake?
Idea Re: Simulating and calculating Geometric Factors in GEANT4  by Laurent Desorgher <Laurent Desorgher>,   02 Oct, 2012
Re: Question Simulating and calculating Geometric Factors in GEANT4 (Bruno Morgado)
Dear Bruno,

I think that your normalization formula is wrong. What puzzled me is the 8 and pi^2 factors. Indeed if you define the geometrical factor as the factor by which the omnidirectional isotropic flux ( flux and not current!) should be multiplied to get your normalized counts then your normalized signal SN should be

SN=(Source_surface/4.)*nb_detected_particles/nb_generated_particles =pi*R^2*nb_detected_particles/nb_generated_particles

It is always usefull to make a normalization test with geantino where you do register the n.b. of geantino entering your sensitive detector. Your normalized signal or geometric factor should be the external surface of your sensitive detector divided by 4.

Best Regards

Laurent

On Tue, 26 Jun 2012 11:53:20 GMT, Bruno Morgado wrote:

> Hello,
> I'm trying to calculate the "real" Geometric Factor (GF) of an instrument in Geant, but I'm having some problems with the results.
> 
> My macro file is:
> # Set GPS spherical source
> /gps/particle e-                        # particle type
> /gps/pos/type Surface
> /gps/pos/shape Sphere
> /gps/centre 0 0 0 m                     # source centre
> /gps/pos/radius 10 cm
> /gps/ang/type cos
> /gps/ene/mono 52. keV
> /run/beamOn 200000000
> 
> And I finish calculating the GF with:
> double geometryFactor(double numberDetectedParticles, double numberEmitedParticles, const double sourceRadius) {
>     return ((8 * numberDetectedParticles * pow(TMath::Pi(), 2) * pow(sourceRadius, 2)) / numberEmitedParticles);
> }
> 
> Still, like I said the results don't seem to add up. Can you direct me to some place where I can check if these are the correct calculations or if there is some mistake?
> 

None Re: Simulating and calculating Geometric Factors in GEANT4  by Bruno Morgado <Bruno Morgado>,   08 Oct, 2012
Re: Idea Re: Simulating and calculating Geometric Factors in GEANT4 (Laurent Desorgher)
Hi Laurent, thank you for you answer. I found out that original expressions was indeed wrong, but the one I found after is also different from yours.

The expressions I found for the Geometric Factor G, is:

G = (Nc/Ne) * 4 * Pi^2 * R^2

where: Nc = Number of captured particles Ne = N. emitted particles R =Source radius

I came to this by using a paper from Sullivan, 1971.

The Counting rate C is related to the Isotropic source intensity (I0) by: C = G * I0

Excluding any time dependency, the Intensity becomes the number of emitted, and captured particles.

If I define a source sphere where the particles are only emitted inwards, then the solid angle, O, comprised by those particles is: O = Pi

and the source intensity becomes: I0 = Ne / (S * O) = Ne / (4 * Pi^2 * R^2)

where: S = Surface area

and using the definition of G from Sullivan, I arrive at the GF I've given before.

All the best, Bruno

None Re: Simulating and calculating Geometric Factors in GEANT4  by Laurent Desorgher <Laurent Desorgher>,   08 Oct, 2012
Re: None Re: Simulating and calculating Geometric Factors in GEANT4 (Bruno Morgado)
I think that the difference between our two normalisation factors come from the fact that my GF refers to omnidirectional flux while yours refer porba bly to directional flux. This would explain the 4pi factor of difference.

Laurent

Question Dose equivalent  by Geng <Geng>,   23 Jun, 2012
Dear experts:

I want to know something detail about the dose equivalent part.

I only have the method to calculate the absorb dose but not the dose equivalent.

Could you tell me the detail method in geant4 to realize the dose equivalent calculation with quality factor?

Or you may only send an example code of this part,I would study it by myself.

Thanks and best regards!

None Re: Dose equivalent  by Youming Yang <Youming Yang>,   24 Jun, 2012
Re: Question Dose equivalent (Geng)
Hello Geng,

In general, please provide more detail in your queries.

Are you inquiring about biological doses (dose equivalent and equivalent dose)? If so, I am not sure "space applications" is quite where you should be looking for your answers.

If you are indeed inquiring regarding the biological doses, the question you have asked involves quite a bit more work than just viewing another person's sample code. You should review literature on the following topics:

The meaning behind dose equivalent and equivalent dose [Sv] in relation to just dose [Gy] (also [J/kg]).

Once you understand this, you should review literature on the calculations of dose equivalent and equivalent dose. One involves weighing factors involving specific organs within a human body, the other involves the beam quality you mentioned, but still in relation to a human body.

Finally, within your code itself, for any geometry which you define to be part of the body, you may scale energy deposited (search for edep in one of the many examples) by the appropriate quality factor, and score that value instead.

Ming

On Sat, 23 Jun 2012 09:44:36 GMT, Geng wrote:

> Dear experts:
> 
> I want to know something detail about the dose equivalent part.
> 
> I only have the method to calculate the absorb dose but not the dose
> equivalent.
> 
> Could you tell me the detail method in geant4 to realize the dose
> equivalent calculation with quality factor?
> 
> Or you may only send an example code of this part,I would study it by
> myself.
> 
> Thanks and best regards!
> 

Question Re: Dose equivalent  by Geng <Geng>,   24 Jun, 2012
Re: None Re: Dose equivalent (Youming Yang)
Hello Ming,

Thanks for your kindly reply!

Yes,you are right.I am talking about the biological doses here. The reason I look for answers here is there are many articles in space application talk about that. I have reviewed many literatures about that,the meaning of dose equivalent is also clear.(scale energy deposited by the appropriate quality factor). I think the question that confused me is how to get the appropriate quality factor(or LET instead) in Geant4. So could you give me some advise about that?

Thanks Very much! Best regards! Geng

Question How to get secondary particle (e.g. muon) flux?  by Halil <Halil>,   15 May, 2012
Hello Geant4 users;

I am working on the simulation of the cosmic muons using Geant4. I am trying to get flux at sea level using the primary particle flux which is given in unit (m2 sr s GeV)^-1 from balloon measurements. I shoot primary particles on the top of the atmosphere using GPS (general particle source) and record all the muons energy, angle etc. at sea level. The problem I am having is that I do not know how to express the muon's flux with the unit (cm2 sr s GeV)^-1.

Because of the possible scatterings and decays, muons spread a wide area at sea level with different angles. (For instance, when I shoot the protons vertically, muons reach the earth's surface with an angle in a range from 0 to 25 degree.) Therefore, I dont know wheter I should count all the muons reaching the sea level regardless of their angle or I sould do correction by dividing the total number by the detector area etc. Namely, how can I convert the number of muon events I obtained into the muon flux in proper units for a comparison with the measurements?

Thanks in advance

Question Define "differential energy spectrum"  by Geng <Geng>,   11 Mar, 2012
Hi Sir/madam

   Thanks in advance!
   I am a fresh man in Geant4.I want to simulate a source with a "differential energy spectrum" , just like a GCR proton spectrum.
   Could you give me some advice to solute it?
   I need your suggestions urgently!
Thanks very much!
Geng

None Re: Define   by michel maire <michel maire>,   12 Mar, 2012
Re: Question Define "differential energy spectrum" (Geng)
On Sun, 11 Mar 2012 16:43:54 GMT, Geng wrote:
> Hi Sir/madam
> 
>    Thanks in advance!
>    I am a fresh man in Geant4.I want to simulate a source with a "differential energy spectrum" , just like a GCR proton spectrum.
>    Could you give me some advice to solute it?
>    I need your suggestions urgently!
> Thanks very much!
> Geng
> 

 I do not know what you call differential energy spectrum, nor GCR proton spectrum. If you mean generate particles according a predefined distribution, you may use General Particle Source, as mentioned by Susanna.
 You may also do it yourself with simple particle gun. This is shown in :
 examples/extended/eventgenerator/particleGun
 See readme and PrimaryGeneratorAction2

None RE: Define "differential energy spectrum"  by Susanna <Susanna>,   11 Mar, 2012
Re: Question Define "differential energy spectrum" (Geng)
Dear Geng,

you may use the General Particle Source (GPS) (http://reat.space.qinetiq.com/gps/). 
The advanced example cosmicray_charging shows  how to use the GPS.

If you do not wish to use the GPS, you may refer to the advanced example radioprotection.

Best wishes,
Susanna

Dr. Susanna Guatelli
Centre for Medical Radiation Physics
School of Engineering Physics
University of Wollongong, NSW 2522
Australia,
Email: susanna@uow.edu.au
Phone: +61 2 4221 4374
Fax +61-2-42214955
________________________________________
From: Geng [crgeng_medphy@yahoo.cn]
Sent: 12 March 2012 03:43
To: space_app-g4hn@slac.stanford.edu
Subject: Define "differential energy spectrum"

*** Discussion title: Space Applications

Hi Sir/madam

   Thanks in advance!
   I am a fresh man in Geant4.I want to simulate a source with a "differential energy spectrum" , just like a GCR proton spectrum.
   Could you give me some advice to solute it?
   I need your suggestions urgently!
Thanks very much!
Geng

-------------------------------------------------------------
Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or unsubscribe) at:
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Question 2011 Geant4 Space User Workshop  by wangym <wangym>,   17 Sep, 2011
hollo, I am a Geant4 user. I want to ask that Do 2011 Geant4 Space User Workshop call for paper ? I want to submit a paper, my teacher tell me if the paper has be received , I can attend the meeting.

Question Re: 2011 Geant4 Space User Workshop  by wangym <wangym>,   20 Sep, 2011
Re: Question 2011 Geant4 Space User Workshop (wangym)
hollo, I am a Geant4 user. I want to ask that Do 2011 Geant4 Space User Workshop call for paper ? I want to submit a paper, my teacher tell me if the paper has be received , I can attend the meeting.

Question Defining the integration time using a primary event number  by Manuel Castro Avila <Manuel Castro Avila>,   14 Oct, 2010
Hi everyone,

I like your help.


I have to simulate the behavior of an instrument during a exposition time to the radiation, in this case, to gamma photons. The instrument has a detector with size of 169 cm^{2} and 50 cm away from the detector, there is an aperture of 1332.25 cm^{2}.

So, I have the power law that represent the energy distribution of the photon spectrum that I go to use. The power law is the following:

5.16x10^{-2} E^{-1.81} ph cm^{-2} Sr^{-1} s^{-1} MeV^{-1}

This power law is valid between 0.04 MeV to 10 Mev.

I need to calculate the number of primary events that represent a exposition time, for instance, 4 hours. To calculate this number, I calculate the integral among the energy range and I get:

0.854 ph cm^{-2} Sr^{-1} s^{-1} MeV{-1}

-The integration time is: 4h=14400 s
-I want to integrate over 4*PI Sr (I considere a isotropic flux into my simulation using GPS from GEANT 4)
-The detector area is of 169 cm^{2}

Now, to get the total number photons, I multiply the number above (0.854 ph ...) by 14400*4*PI*169 and I get the total primary event number equals 26116617.68 photons.

My macro file is:

/gps/particle gamma
/gps/pos/type Surface
/gps/pos/shape Sphere
/gps/pos/radius 60. cm
/gps/pos/centre 0.0 0.0 0.0 cm
/gps/ang/type cos

/gps/ene/type Pow
/gps/ene/min 1 MeV
/gps/ene/max 10 MeV
/gps/ene/alpha -1.8

/run/beamOn 26116617

My question is: Is this procedure above correct?? Am I using the correct way to calculate the integration time??

By the other hand, the power law represent the photon background measured in the atmosphere to a atmospheric depth of 3.5 g cm^{-2}, is there a way to adapt this power law to the case where the atmospheric depth is of 2.8 g cm^{-2}???

Thanks,

Manuel

Question How to simulate GCR spectra   by aimsphere <aimsphere>,   15 Jun, 2010
Hello,

I have a question regarding the use of GPS for simulating the entire GCR. I wanted to get some suggestion regarding how to do this. I have made simulations for individual particle specie using mac files for each individually. Now since I would like to consider ions from Atomic no. 1 to 28 I was wondering if the only way to do is to make simulations for each ion using their respective individual mac files or is there some other way to do this?

Thank you.
None Re: How to simulate GCR spectra   by Hugh Evans <Hugh Evans>,   25 Jun, 2012
Re: Question How to simulate GCR spectra (aimsphere)
You can set up multiple sources using the GPS. An example of multiple sources is here

An example from the MC-SCREAM module on SPENVIS is as follows, which combines the Trapped proton, trapped electron and solar proton particle spectra into a single macro file with 3 separate sources. You will also have to establish the geometry for each of the sources (with Mulassis, this is built in using the /geometry/setGPSsource macro command.

Note, the use of the /gps/source/intensity and /analysis/normalise to correctly normalise the outputs.

Hugh


# =============================
# SPENVIS particle source
# Particle type: trapped protons
# =============================
/gps/particle proton
/gps/ene/type Arb
/gps/ene/diffspec true
/gps/hist/type arb
/gps/ene/min    1.000E-01 MeV
/gps/ene/max    4.000E+02 MeV
/gps/source/intensity    9.664E+11
/gps/hist/point    1.000E-01    5.729E+04
/gps/hist/point    1.500E-01    4.074E+04
/gps/hist/point    2.000E-01    2.705E+04
/gps/hist/point    3.000E-01    1.256E+04
/gps/hist/point    4.000E-01    6.622E+03
/gps/hist/point    5.000E-01    3.560E+03
/gps/hist/point    6.000E-01    2.167E+03
/gps/hist/point    7.000E-01    1.370E+03
/gps/hist/point    1.000E+00    5.976E+02
/gps/hist/point    1.500E+00    1.887E+02
/gps/hist/point    2.000E+00    9.714E+01
/gps/hist/point    3.000E+00    3.763E+01
/gps/hist/point    4.000E+00    2.164E+01
/gps/hist/point    5.000E+00    1.388E+01
/gps/hist/point    6.000E+00    1.068E+01
/gps/hist/point    7.000E+00    8.528E+00
/gps/hist/point    1.000E+01    5.312E+00
/gps/hist/point    1.500E+01    2.775E+00
/gps/hist/point    2.000E+01    1.945E+00
/gps/hist/point    3.000E+01    1.273E+00
/gps/hist/point    4.000E+01    1.053E+00
/gps/hist/point    5.000E+01    9.199E-01
/gps/hist/point    6.000E+01    8.260E-01
/gps/hist/point    7.000E+01    7.684E-01
/gps/hist/point    1.000E+02    5.931E-01
/gps/hist/point    1.500E+02    3.748E-01
/gps/hist/point    2.000E+02    2.325E-01
/gps/hist/point    3.000E+02    9.639E-02
/gps/hist/point    4.000E+02    8.389E-03

/gps/hist/inter Lin

/gps/ang/type cos
/gps/ang/mintheta 0.0E+00 deg
/gps/ang/maxtheta 9.0E+01 deg

# =============================
# SPENVIS particle source
# Particle type: trapped electrons
# =============================
/gps/source/add 1
/gps/particle e-
/gps/ene/type Arb
/gps/ene/diffspec true
/gps/hist/type arb
/gps/ene/min    4.000E-02 MeV
/gps/ene/max    6.500E+00 MeV
/gps/source/intensity    3.289E+13
/gps/hist/point    4.000E-02    2.041E+06
/gps/hist/point    1.000E-01    1.496E+06
/gps/hist/point    2.000E-01    6.885E+05
/gps/hist/point    3.000E-01    2.358E+05
/gps/hist/point    4.000E-01    1.071E+05
/gps/hist/point    5.000E-01    5.581E+04
/gps/hist/point    6.000E-01    2.891E+04
/gps/hist/point    7.000E-01    1.983E+04
/gps/hist/point    8.000E-01    1.356E+04
/gps/hist/point    1.000E+00    7.708E+03
/gps/hist/point    1.250E+00    4.452E+03
/gps/hist/point    1.500E+00    2.688E+03
/gps/hist/point    1.750E+00    1.633E+03
/gps/hist/point    2.000E+00    1.065E+03
/gps/hist/point    2.250E+00    6.980E+02
/gps/hist/point    2.500E+00    4.949E+02
/gps/hist/point    2.750E+00    3.438E+02
/gps/hist/point    3.000E+00    2.088E+02
/gps/hist/point    3.250E+00    1.314E+02
/gps/hist/point    3.500E+00    8.486E+01
/gps/hist/point    3.750E+00    5.703E+01
/gps/hist/point    4.000E+00    3.705E+01
/gps/hist/point    4.250E+00    2.440E+01
/gps/hist/point    4.500E+00    1.440E+01
/gps/hist/point    4.750E+00    8.574E+00
/gps/hist/point    5.000E+00    4.909E+00
/gps/hist/point    5.500E+00    1.777E+00
/gps/hist/point    6.000E+00    4.156E-01
/gps/hist/point    6.500E+00    6.083E-02

/gps/hist/inter Lin

/gps/ang/type cos
/gps/ang/mintheta 0.0E+00 deg
/gps/ang/maxtheta 9.0E+01 deg

# =============================
# SPENVIS particle source
# Particle type: solar proton
# =============================
/gps/source/add 1
/gps/particle proton
/gps/ene/type Arb
/gps/ene/diffspec true
/gps/hist/type arb
/gps/ene/min    1.000E-01 MeV
/gps/ene/max    5.000E+02 MeV
/gps/source/intensity    1.828E+10
/gps/hist/point    1.000E-01    1.250E+11
/gps/hist/point    1.100E-01    1.177E+11
/gps/hist/point    1.200E-01    1.110E+11
/gps/hist/point    1.400E-01    9.980E+10
/gps/hist/point    1.600E-01    9.069E+10
/gps/hist/point    1.800E-01    8.322E+10
/gps/hist/point    2.000E-01    7.696E+10
/gps/hist/point    2.200E-01    7.169E+10
/gps/hist/point    2.500E-01    6.505E+10
/gps/hist/point    2.800E-01    5.955E+10
/gps/hist/point    3.200E-01    5.350E+10
/gps/hist/point    3.500E-01    4.973E+10
/gps/hist/point    4.000E-01    4.453E+10
/gps/hist/point    4.500E-01    4.024E+10
/gps/hist/point    5.000E-01    3.667E+10
/gps/hist/point    5.500E-01    3.370E+10
/gps/hist/point    6.300E-01    2.978E+10
/gps/hist/point    7.100E-01    2.658E+10
/gps/hist/point    8.000E-01    2.367E+10
/gps/hist/point    9.000E-01    2.102E+10
/gps/hist/point    1.000E+00    1.885E+10
/gps/hist/point    1.100E+00    1.703E+10
/gps/hist/point    1.200E+00    1.552E+10
/gps/hist/point    1.400E+00    1.310E+10
/gps/hist/point    1.600E+00    1.119E+10
/gps/hist/point    1.800E+00    9.692E+09
/gps/hist/point    2.000E+00    8.488E+09
/gps/hist/point    2.200E+00    7.513E+09
/gps/hist/point    2.500E+00    6.343E+09
/gps/hist/point    2.800E+00    5.423E+09
/gps/hist/point    3.200E+00    4.467E+09
/gps/hist/point    3.500E+00    3.906E+09
/gps/hist/point    4.000E+00    2.835E+09
/gps/hist/point    4.500E+00    2.019E+09
/gps/hist/point    5.000E+00    1.743E+09
/gps/hist/point    5.500E+00    1.523E+09
/gps/hist/point    6.300E+00    1.247E+09
/gps/hist/point    7.100E+00    1.035E+09
/gps/hist/point    8.000E+00    8.539E+08
/gps/hist/point    9.000E+00    6.997E+08
/gps/hist/point    1.000E+01    4.989E+08
/gps/hist/point    1.100E+01    3.430E+08
/gps/hist/point    1.200E+01    3.036E+08
/gps/hist/point    1.400E+01    2.424E+08
/gps/hist/point    1.600E+01    1.962E+08
/gps/hist/point    1.800E+01    1.616E+08
/gps/hist/point    2.000E+01    1.349E+08
/gps/hist/point    2.200E+01    1.142E+08
/gps/hist/point    2.500E+01    9.051E+07
/gps/hist/point    2.800E+01    6.820E+07
/gps/hist/point    3.200E+01    4.121E+07
/gps/hist/point    3.500E+01    3.112E+07
/gps/hist/point    4.000E+01    2.539E+07
/gps/hist/point    4.500E+01    2.096E+07
/gps/hist/point    5.000E+01    1.754E+07
/gps/hist/point    5.500E+01    1.489E+07
/gps/hist/point    6.300E+01    1.166E+07
/gps/hist/point    7.100E+01    9.265E+06
/gps/hist/point    8.000E+01    7.293E+06
/gps/hist/point    9.000E+01    5.683E+06
/gps/hist/point    1.000E+02    4.493E+06
/gps/hist/point    1.100E+02    3.599E+06
/gps/hist/point    1.200E+02    2.937E+06
/gps/hist/point    1.400E+02    2.008E+06
/gps/hist/point    1.600E+02    1.393E+06
/gps/hist/point    1.800E+02    1.005E+06
/gps/hist/point    2.000E+02    7.394E+05
/gps/hist/point    2.200E+02    5.536E+05
/gps/hist/point    2.500E+02    3.701E+05
/gps/hist/point    2.800E+02    2.512E+05
/gps/hist/point    3.200E+02    1.515E+05
/gps/hist/point    3.500E+02    1.057E+05
/gps/hist/point    4.000E+02    6.074E+04
/gps/hist/point    4.500E+02    3.483E+04
/gps/hist/point    5.000E+02    1.596E+04

/gps/hist/inter Lin

/gps/ang/type cos
/gps/ang/mintheta 0.0E+00 deg
/gps/ang/maxtheta 9.0E+01 deg

/analysis/normalise    3.388E+13 cm2
Question Re: How to simulate GCR spectra   by Geng <Geng>,   24 Jun, 2012
Re: Question How to simulate GCR spectra (aimsphere)
Dear Dr:

I think this is a good question. I wonder have you solute this problem? Could you share something with me? Thanks very much!

Best regards! geng

Question Normalization of an isotropic flux in space  by valentina <valentina>,   03 Mar, 2009
Dear all,

I am simulating the interaction of a space telescope with the cosmic ray environment and, after a long discussion with my colleagues, I am a bit confused on the normalization process that translates the number of counts in my detector in unity of counts/cm^2 sec.

So I really appreciate if somebody could help me to clarify this topic!

I show here what is my normalization way.

I have an isotropic proton flux F:

F = prot /cm^2 sec sr

I run the protons from a sphere of radius R within an half cone angle q to increase the statistics. My spacecraft is placed within the emission angle, that is the spacecraft is placed within the sphere of radius r, with

r = tan(q) x R

The GPS macro is:

/gps/particle proton

/gps/pos/type Surface

/gps/pos/shape Sphere

/gps/pos/radius 50.0 m ---> R

/gps/pos/centre 0.0 0.0 0.0 mm

/gps/ang/type iso

/gps/ang/mintheta 0 rad

/gps/ang/maxtheta 0.01 rad ---> q

while the spectral shape is made via /gps/hist .

At the end of the run, I detect a number of counts C on the focal plane. If N is the number of emitted protons, we call the fraction of detected/emitted particles Eff:

Eff = C/N

In order to trasform the number C to a rate P in counts/sec, I apply this formula:

P = Eff x F x (4 x PI) x PI x r^2 counts/sec

Then I divide the count rate P by the detecting area Adet, and the final flux B is given by:

B = P/Adet counts/cm^2 sec

The same normalization can be achieved using the simulation time:

D = F x A_sphere x omega prot/sec

where:

- A_sphere = 4 x PI x R^2 (the source sphere)

- omega = 2 x PI x (1 - cos(q)) (solide angle of the emission cone)

Then we calculate the simulated time:

Time = N/D (sec)

The flux B on the focal plane is given by:

B = C/(Time x Adet) counts/cm^2 sec

My normalization way is based on what shown by Sullivan (1971).

Now my question is: is this the right way?

Thank you all for the help!

Best regards, Valentina

None Re: Normalization of an isotropic flux in space  by Paul Nicholas Colin Gloster <Paul Nicholas Colin Gloster>,   03 Mar, 2009
Re: Question Normalization of an isotropic flux in space (valentina)
Valentina Fioretti submitted:
|----------------------------------|
|"[..]                             |
|                                  |
|I have an isotropic proton flux F:|
|                                  |
|F = prot /cm^2 sec sr"            |
|----------------------------------|

Dear Valentina Fioretti,

As you called that a flux, was that supposed to be
F = #protons / (centimeter^2 second steradian)
instead of what you seemed to type which was equivalent to
#protons second steradian / centimeter^2?


|------------------------------------------------------------------------|
|"[..]                                                                   |
|                                                                        |
|At the end of the run, I detect a number of counts C on the focal plane.|
|If N is the number of emitted protons, we call the fraction of          |
|detected/emitted particles Eff:                                         |
|                                                                        |
|Eff = C/N                                                               |
|                                                                        |
|In order to trasform the number C to a rate P in counts/sec, I apply    |
|this formula:                                                           |
|                                                                        |
|P = Eff x F x (4 x PI) x PI x r^2 counts/sec"                           |
|------------------------------------------------------------------------|

Eff can be treated as a dimensionless ratio (well strictly, its unit is count per proton). The unit of F, assuming F = #protons / (centimeter^2 second steradian), is count / (centimeter^2 second steradian).
Therefore, the unit of Eff x F is also count / (centimeter^2 second steradian).
For the unit of the P to be count/second, the unit of (4 x pi) x pi x r^2 would need to be centimeter^2 steradian.
It is not clear how you obtained the expression (4 x pi) x pi x r^2.



|-------------------------------------------------------------------------|
|"Then I divide the count rate P by the detecting area Adet, and the final|
|flux B is given by:                                                      |
|                                                                         |
|B = P/Adet counts/cm^2 sec"                                              |
|-------------------------------------------------------------------------|

If the unit of P is count/second then the unit of B is count/(cm^2 second), which you seemed to realize but you typed something else.


|--------------------------------------------------------------------|
|"The same normalization can be achieved using the simulation time:  |
|                                                                    |
|D = F x A_sphere x omega prot/sec                                   |
|                                                                    |
|where:                                                              |
|                                                                    |
|- A_sphere = 4 x PI x R^2 (the source sphere)                       |
|                                                                    |
|- omega = 2 x PI x (1 - cos(q)) (solide angle of the emission cone)"|
|--------------------------------------------------------------------|

The solid angle subtended by the detector at the source of the protons depends at least on the detector surface that faces the source and the distance between the detector and the source. You do not seem to have informed us of the distance. Omega = 2 x pi x (1 - cos(q)) may or may not apply for your situation.
For the correct value of Omega, the unit of F x A_sphere x Omega is indeed protoncount/second.



|--------------------------------------|
|"Then we calculate the simulated time:|
|                                      |
|Time = N/D (sec)"                     |
|--------------------------------------|

Agreed.



|-------------------------------------------|
|"The flux B on the focal plane is given by:|
|                                           |
|B = C/(Time x Adet) counts/cm^2 sec"       |
|-------------------------------------------|

Yes (with the unit being count/(centimeter^2 second)).


|----------------------------------------------------------------|
|"My normalization way is based on what shown by Sullivan (1971).|
|                                                                |
|Now my question is: is this the right way?                      |
|                                                                |
|[..]"                                                           |
|----------------------------------------------------------------|

Bear in mind that the flux reaching the detector (as opposed to merely the spacecraft) would be affected by the corresponding geometric factor of the detector, which can be affected by the particles' trajectories through the instrument (therefore different energies may have different geometric factors) and the geometry of the instrument.

It seems that you referred to Sullivan, J. D., 1971, "Geometrical factor and directional response of single and multi-element particle telescopes". I do not have a copy of this and I do not know enough about what you are trying to simulate so I do not say much more. You may wish to read
Sullivan, J. D.,
1972,
"Erratum: Geometrical factor and directional response of single and multi-element particle telescopes, Nucl. Instr. and Meth. 95 (1971) 5-11"
,
HTTP://DX.DOI.org/10.1016/0029-554X(72)90450-8
, "Nuclear Instruments and Methods", Volume 98, Issue 1, Page 187.

Regards,
Colin Paul Gloster
Feedback Re: Normalization of an isotropic flux in space  by Giovanni Santin <Giovanni Santin>,   03 Mar, 2009
Re: Question Normalization of an isotropic flux in space (valentina)
Dear Valentina

the paper by Sullivan is indeed a good starting point for normalisation issues.

I tend to agree on your 1st final formula.

I see a problem in your macro, as you use "iso" for the angular distribution. In fact, if you want to generate an isotropic source in a volume starting from a surface, you have to bias the angular distribution with a cosine-law function, that means using "cos" in GPS.

Some time ago I tried to summarise all this in some diagrams, you can find a presentation at: http://geant4.in2p3.fr/2007/prog/GiovanniSantin/GSantin_Geant4_Paris07_Normalisation_v07.ppt

There, the final formula I get at slide #10 is equivalent to your first one, if you substitute Xs=C/Adet , q=thetamax , F=Phi

At the last slide, I include a couple more useful references.

Also, it seems to me that the 2nd formula you propose is a factor 2 different from the 1st one (am I right?). Indeed, that might come from the fact that you should integrate the cosine-biased emission, not an isotropic one.

In my calculations, also, if I limit the max emission angle theta to a certain q, I normally get a sin2(q) instead of (1 - cos q), as a result of the integration of the cos-biased distribution.

I hope this can help you, and I am interested in comments from your side

Kind regards, Giovanni

Question Re: Normalization of an isotropic flux in space  by valentina <valentina>,   03 Mar, 2009
Re: Feedback Re: Normalization of an isotropic flux in space (Giovanni Santin)
Dear Giovanni,

thank you for your quick reply!

The fact that you agree with my approach calm me down a lot.

>I see a problem in your macro, as you use "iso" for the angular distribution. In >fact, if you want to generate an isotropic source in a volume starting from a >surface, you have to bias the angular distribution with a cosine-law function, >that means using "cos" in GPS.

Yes, you'r right. The reason is that I am running a cross-checking simulation, and my colleagues use "iso"... I will change it.

>Also, it seems to me that the 2nd formula you propose is a factor 2 different >from the 1st one (am I right?). Indeed, that might come from the fact that you >should integrate the cosine-biased emission, not an isotropic one.
>In my calculations, also, if I limit the max emission angle theta to a certain q, >I normally get a sin2(q) instead of (1 - cos q), as a result of the integration >of the cos-biased distribution.

Yes, the 2nd formula is a more intuitive but approximated approach. Since q is this case a very small angle, the approximation does not affect the result.

From the 1st formula, the simulation time is given by:

Time_1 = N / [F(prot/(cm2 s sr)) x (4 x PI) x (PI x (R x tan(q))^2)]

From the 2nd formula, the time is given by:

Time_2 = N / [F x (4. x PI x R^2) x (2 x PI x (1 - cos(q)))]

For q = 0.01 rad, Time_1 is about Time_2.

If a take q = 0.9, Time_1 is equal to Time_2 for the following formulas:

Time_1 = N / [F(prot/(cm2 s sr)) x (4 x PI) x (PI x (R x sin(q))^2)]

Time_2 = N / [F x (4. x PI x R^2) x (2 x PI x (1/2 - (cos(q)^2)/2))]

(I take the cosin-law function)

Apart from the differences with these two formulas, my problem is that another normalization approach has been presented to me.

Since the intersection of infinite cones originating from the source sphere (radius R) would give the surface of the small sphere of radius r, the simulation time is given by:

Time_B = N/[F(prot/(cm2 s sr)) x (4 x PI) x (4 x PI x (R x sin(q))^2)]

Note the factor 4, that gives the area of the sphere surface and not of the plane of radius r.

The simulation time is 4 times lower than "my" simulation time.

Consider of having an isotropic flux, integrated over 4PI, of:

F = 2.31 #protons / (cm^2 sec)

If we run a simulation with a simple geometry made of a total absorbing cube placed within the small sphere (of radius r), what is the proton count rate that you expect on the cube surface?

If you use the last normalization, you obtain 2.31 counts/(cm^2 sec). My objection is that the proton count rate on the cube surface is not the flux integrated over 4PI, but (using the cosin law) over PI, because every cube side sees only PI sr.

What do you think of this different normalization? And, the most important, how one could prove the accuracy of one normalization approach respect to the other?

Thank you Giovanni!

Best regards, Valentina

Note Re: Normalization of an isotropic flux in space  by Juan <Juan>,   04 Mar, 2009
Re: Question Re: Normalization of an isotropic flux in space (valentina)
Dear Valentina

    If a take q = 0.9, Time_1 is equal to Time_2 for the following formulas:
    Time_1 = N / [F(prot/(cm2 s sr)) x (4 x PI) x (PI x (R x sin(q))2)]
    Time_2 = N / [F x (4. x PI x R2) x (2 x PI x (1/2 - (cos(q)2)/2))]

Notice this seem normal to me as both equations are the same

Time_1 = N/F x 4 PI^2 x R^2 x sin(p)^2
Time_2 = N/F x 4 PI^2 x R^2 x 2 x 1/2 x (1-cos(p)^2) =
      = N/F x 4 PI^2 x R^2 x sin(p)^2

From what Giovanni shows in his presentation, if I understand well, when you have a sphere of radius r as sensitive volume inside a sphere of radius R which is surrounded by an isotropic flux F

Nr = F 4PI^2 R^2

is the number of particles per second traversing the big sphere and entering in this volume. So in G4 if you make beamOn Nr you simulate the number of particles entering in the big volume in one second.

When you only need the particles hitting the little sphere, to save time, you look only the particles in the big sphere having a incident angle lower than q where r = R sin(q) this gives the rate of particles entering in the little volume per second in page 11 of Giovanni's presentation.

Nr = F 4PI^2 R^2 sin(q)^2

For me this is equal to

Nr = F 4PI^2 r^2

Is like if you put the source on the surface of the little sphere without limitation of angle q. And if you do beamOn Nr you simulate the number of particles entering the little sensitive volume in one second. beamOn 100xNr will simulate 100 seconds, etc.

If I want to know how many particles will enter a little cube of side L per second. What I will do is to put the cube inside a sphere of radius

r = sqrt(3)/2 L

Which is 1/2 of the big diagonal of your cube. So you have the smaller sphere surrounding your cube. As in precedent case I will use

Nr = F 4PI^2 r^2

Then, doing beamOn Nr, I will count in my GEANT4 program the number of particles entering the cube per second Nc. The geometric factor of the cube omega can be found as

Nc = F omega

dividing both equations :

Nc/Nr = F/F omega/(4PI^2 r^2)

omega = Nc/Nr (4PI^2 r^2)

This geometrical factor gives you the number or particles entering in the cube per second when you know the external flux. The geometric factor is independent of the particle energy. Now, if you have a detector perhaps you have to take in account the detection efficiency which depends of the incoming energy.

Juan Cabrera

Ok Re: Normalization of an isotropic flux in space  by valentina <valentina>,   04 Mar, 2009
Re: Note Re: Normalization of an isotropic flux in space (Juan)
Dear Juan,

thank you for your reply!

> 
>     If a take q = 0.9, Time_1 is equal to Time_2 for the following formulas:
>     Time_1 = N / [F(prot/(cm2 s sr)) x (4 x PI) x (PI x (R x sin(q))2)]
>     Time_2 = N / [F x (4. x PI x R2) x (2 x PI x (1/2 - (cos(q)2)/2))]
> 
> Notice this seem normal to me as both equations are the same
> 
> Time_1 = N/F x 4 PI^2 x R^2 x sin(p)^2
> Time_2 = N/F x 4 PI^2 x R^2 x 2 x 1/2 x (1-cos(p)^2) =
>       = N/F x 4 PI^2 x R^2 x sin(p)^2
> 

Yes, they are the same in the exact formulation. Giovanni made me notice in the previous message that I was using an approximated formulation, that doesn't work for larger angles.

> Then, doing beamOn Nr, I will count in my GEANT4 program the number of
> particles entering the cube per second Nc. The geometric factor of the
> cube omega can be found as
> 
> Nc = F omega
>

Since F is [#protons / (cm^2 sec sr)], here you forgot to mention the cube area (the detecting area):

Nc = F x omega x A_cube

> dividing both equations :
> 
> Nc/Nr = F/F omega/(4PI^2 r^2)
> 

Nc/Nr = F/F (omega x A_cube) /(4PI^2 r^2)

> omega = Nc/Nr (4PI^2 r^2)
> 

omega = (Nc/Nr) x (4PI^2 r^2) x A_cube

If you try to run this simulation test, you obtain omega = PI, that is just what I am saying.

I am glad to see that you agree!

Shifting from the simulation to a real case, if you have an isotropic flux:

F = # protons/ (cm^2 sec sr)

What is the flux that you expect on the cube? From the two approaches that I have presented, two are the options:

1) F x omega = F x PI (my normalization way)

2) F x 4PI

Or, if you have an ideal (detection efficiency = 1) detector in space exposed to a 4PI isotropic flux, what is the detected count rate in counts/(cm2 sec)?

1) F x PI?

2) F x 4PI?

What do you think?

Thanks!

Warm regards, Valentina

None Re: Normalization of an isotropic flux in space  by Juan <Juan>,   04 Mar, 2009
Re: Ok Re: Normalization of an isotropic flux in space (valentina)
Dear Valentina,

I should call the geometric factor Gf (cm2 sr) not omega which is used for solid angle (sr). This can do a bad interpretation of the formula I wrote

Nc = F Gf

Which gives the number of particles per second entering in the cube.

From Giovanni presentation page 10 Method 1, if I'm not wrong, the Gf can be calculate multiplying PI x Surface. For a cube the surface presented to the flux is 6 L^2.

Then, the number of particles per second is

Nc = F (PI 6 L ^2)

Now, if you want to have the number of particles entering in the cube per cm2 per second you divide by the cube area

Nc/cm2 = F PI

Which is what you want.

Juan

Question gps sphere source   by Daniel Braun <Daniel Braun>,   09 Oct, 2008
Hallo,

I need to use a sphere as a particle source with the gps class.

and I want the particles to shoot just in the inside of the sphere maximally tangential to the sphere. They also should be distributed even on the surface of the sphere.

What is the best way to realize this?

Thanks for any help.

Regards Daniel

Feedback Re: gps sphere source   by Giovanni Santin <Giovanni Santin>,   10 Oct, 2008
Re: Question gps sphere source (Daniel Braun)
Hello Daniel,

> I need to use a sphere as a particle source with the gps class.
> 
> and I want the particles to shoot just in the inside of the sphere

GPS is indeed a good choice, it will make your life easy.
For generating particles on the surface of a sphere, you can insert this in your macro:

/gps/pos/type Surface
/gps/pos/shape Sphere
/gps/pos/radius 2.0 m
/gps/pos/centre 0. 0. 0. cm

> They also should be distributed even on the surface of the sphere.

The vertices will be automatically uniformly distributed on the surface.

For the angular distribution:
During the run, for each point, randomly generated on the surface, GPS orients +z of the "generation frame" as normal to the surface, directed towards inside.

Normally, then, for generating particles inside the sphere to reproduce an isotropic angular distribution, one has to specify a "cosine law" biasing, and let the theta go from 0 to 90 degrees:

/gps/ang/type cos
/gps/ang/mintheta 0 deg
/gps/ang/maxtheta 90 deg

I am not sure what you mean with 

> maximally tangential to the sphere. 

If you really want the particles to only start parallel to the surface, you can just modify the mintheta to 90 degrees:

/gps/ang/mintheta 90 deg
/gps/ang/maxtheta 90 deg

If instead you mean only normal to the surface (i.e. directed to the centre of the generation sphere) you set maxtheta to 0 degrees.

/gps/ang/mintheta 0 deg
/gps/ang/maxtheta 0 deg

I hope this helps
Kind regards,
Giovanni

ESA / ESTEC
Space Environments and Effects
e-mail: Giovanni.Santin@esa.int

None Re: gps sphere source   by Daniel Braun <Daniel Braun>,   10 Oct, 2008
Re: Feedback Re: gps sphere source (Giovanni Santin)
Hallo Giovanni, thank you very much for your answer.

I tried everything like you explained it but I think there still must be a fault somewhere in my macro.

To check if the particles are all going inside the sphere I made a Detector (green Sphere in the pictures) which has the size of the spherical source. I gave the particles a very small energy so they should stop immediately if they have contact with the Material of the detector. I suspected to get a lot of very short trajectories. Especially for the case of mintheta = 0 and maxtheta = 0. But instead I get trajectories which I can't explain.

In the case of mintheta = 0 and maxtheta = 0 they seem to come just from the middle and in the case of mintheta = 0 and maxtheta = 90 it looks like they are coming form one hemisphere.

I attached some pictures and my macro.

Pleas tell me where I make a mistake.

Regards

Daniel

/control/verbose 0

/control/saveHistory

/run/verbose 0

/event/verbose 0

/vis/scene/create

/vis/open OGLIX

/vis/viewer/zoom 0.4

/vis/scene/add/trajectories

/vis/modeling/trajectories/create/drawByCharge

/vis/modeling/trajectories/drawByCharge-0/default/setDrawStepPts true

/vis/modeling/trajectories/drawByCharge-0/default/setStepPtsSize 2

/vis/scene/endOfEventAction accumulate

/vis/viewer/set/viewpointThetaPhi 0 0 deg

/vis/scene/endOfEventAction accumulate 10000000

/gps/particle proton

/gps/pos/centre 0 0 0

/gps/pos/type Surface

/gps/pos/shape Sphere

/gps/pos/radius 116 mm

/gps/pos/rot1 0 0 1

/gps/ene/type Mono

/gps/energy 0.00000570E-02 eV

/gps/ang/type cos

/gps/ang/mintheta 0 deg

/gps/ang/maxtheta 90 deg

# or /gps/ang/maxtheta 0 deg

/run/beamOn 3000

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2008/10/10/03.59-14287-0_0.eps
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2008/10/10/03.59-30858-0_90.epsOn Fri, 10 Oct 2008 09:08:24 GMT, Giovanni Santin wrote:

None Re: gps sphere source   by Daniel Braun <Daniel Braun>,   30 Oct, 2008
Re: None Re: gps sphere source (Daniel Braun)
Hello,

I also found a mistake in my geometry.

My Detector was lightly shifted which caused a asymmetry.

After removing the rotation of the source and the translation of the detector, everything looks fine.

Thanks for your help Giovanni

Regards

Daniel

Feedback Re: gps sphere source   by Giovanni Santin <Giovanni Santin>,   16 Oct, 2008
Re: None Re: gps sphere source (Daniel Braun)
Hi Daniel

I could indeed reproduce some problematic particle generation cases.
After a few trials with your macro, it seems to me that the 
problem is caused by the command

/gps/pos/rot1 0 0 1 

If I remove it GPS behaves as expected, and for example with maxtheta=0
I see all particles directed towards the centre of the generation sphere.

I will have a look at the GPS code and doc to better understand this 
"feature" of the rot1/rot2 commands.

Thanks for reporting this
Kind regards,
Giovanni

ESA / ESTEC
Space Environments and Effects
e-mail: Giovanni.Santin@esa.int
Feedback Re: gps sphere source   by Giovanni Santin <Giovanni Santin>,   10 Oct, 2008
Re: Question gps sphere source (Daniel Braun)
Hello Daniel,

> I need to use a sphere as a particle source with the gps class.
> 
> and I want the particles to shoot just in the inside of the sphere

GPS is indeed a good choice, it will make your life easy.
For generating particles on the surface of a sphere, you can insert this in your macro:

/gps/pos/type Surface
/gps/pos/shape Sphere
/gps/pos/radius 2.0 m
/gps/pos/centre 0. 0. 0. cm

> They also should be distributed even on the surface of the sphere.

The vertices will be automatically uniformly distributed on the surface.

For the angular distribution:
During the run, for each point, randomly generated on the surface, GPS orients +z of the "generation frame" as normal to the surface, directed towards inside.

Normally, then, for generating particles inside the sphere to reproduce an isotropic angular distribution, one has to specify a "cosine law" biasing, and let the theta go from 0 to 90 degrees:

/gps/ang/type cos
/gps/ang/mintheta 0 deg
/gps/ang/maxtheta 90 deg

I am not sure what you mean with 

> maximally tangential to the sphere. 

If you really want the particles to only start parallel to the surface, you can just modify the mintheta to 90 degrees:

/gps/ang/mintheta 90 deg
/gps/ang/maxtheta 90 deg

If instead you mean only normal to the surface (i.e. directed to the centre of the generation sphere) you set maxtheta to 0 degrees.

/gps/ang/mintheta 0 deg
/gps/ang/maxtheta 0 deg

I hope this helps
Kind regards,
Giovanni

ESA / ESTEC
Space Environments and Effects
e-mail: Giovanni.Santin@esa.int

Question dose depth curve  by Daniel Braun <Daniel Braun>,   12 Sep, 2008
Hello everybody,

I tried to get a Dose depth curve in an Aluminium Sphere and compared it with the one I get from www.Spenvis.oma.be.

But for a thin shield I get not enough Energy deposited and for a thick shield I get to much Energy deposited.

Does anybody know what the Problem is

My Physiks are

// // // $Id: ExN03PhysicsList.cc,v 1.21 2007/07/02 13:22:08 vnivanch Exp $ // GEANT4 tag $Name: geant4-09-01-patch-02 $ // //

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

#include "ExN03PhysicsList.hh"

#include "G4ProcessManager.hh"
#include "G4ParticleTypes.hh"

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

ExN03PhysicsList::ExN03PhysicsList():  G4VUserPhysicsList()
{
  defaultCutValue = 1*mm;
  SetVerboseLevel(1);
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

ExN03PhysicsList::~ExN03PhysicsList() {}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructParticle()
{
  // In this method, static member functions should be called
  // for all particles which you want to use.
  // This ensures that objects of these particle types will be
  // created in the program. 

  ConstructBosons();
  ConstructLeptons();
  ConstructMesons();
  ConstructBaryons();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructBosons()
{
  // pseudo-particles
  G4Geantino::GeantinoDefinition();
  G4ChargedGeantino::ChargedGeantinoDefinition();

  // gamma
  G4Gamma::GammaDefinition();

  // optical photon
  G4OpticalPhoton::OpticalPhotonDefinition();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructLeptons()
{
  // leptons
  G4Electron::ElectronDefinition();
  G4Positron::PositronDefinition();
  G4MuonPlus::MuonPlusDefinition();
  G4MuonMinus::MuonMinusDefinition();

  G4NeutrinoE::NeutrinoEDefinition();
  G4AntiNeutrinoE::AntiNeutrinoEDefinition();
  G4NeutrinoMu::NeutrinoMuDefinition();
  G4AntiNeutrinoMu::AntiNeutrinoMuDefinition();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructMesons()
{
 //  mesons
  G4PionPlus::PionPlusDefinition();
  G4PionMinus::PionMinusDefinition();
  G4PionZero::PionZeroDefinition();
  G4Eta::EtaDefinition();
  G4EtaPrime::EtaPrimeDefinition();
  G4KaonPlus::KaonPlusDefinition();
  G4KaonMinus::KaonMinusDefinition();
  G4KaonZero::KaonZeroDefinition();
  G4AntiKaonZero::AntiKaonZeroDefinition();
  G4KaonZeroLong::KaonZeroLongDefinition();
  G4KaonZeroShort::KaonZeroShortDefinition();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructBaryons()
{
  //  barions
  G4Proton::ProtonDefinition();
  G4AntiProton::AntiProtonDefinition();
  G4Neutron::NeutronDefinition();
  G4AntiNeutron::AntiNeutronDefinition();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructProcess()
{
  AddTransportation();
  ConstructEM();
  ConstructDecay();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

#include "G4ComptonScattering.hh"
#include "G4GammaConversion.hh"
#include "G4PhotoElectricEffect.hh"

#include "G4MultipleScattering.hh"

#include "G4eIonisation.hh"
#include "G4eBremsstrahlung.hh"
#include "G4eplusAnnihilation.hh"

#include "G4MuIonisation.hh"
#include "G4MuBremsstrahlung.hh"
#include "G4MuPairProduction.hh"

#include "G4hIonisation.hh"

#include "G4LowEnergyIonisation.hh" 
#include "G4LowEnergyBremsstrahlung.hh" 

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::ConstructEM()
{
  theParticleIterator->reset();
  while( (*theParticleIterator)() ){
    G4ParticleDefinition* particle = theParticleIterator->value();
    G4ProcessManager* pmanager = particle->GetProcessManager();
    G4String particleName = particle->GetParticleName();

    if (particleName == "gamma") {
      // gamma         
      pmanager->AddDiscreteProcess(new G4PhotoElectricEffect);
      pmanager->AddDiscreteProcess(new G4ComptonScattering);
      pmanager->AddDiscreteProcess(new G4GammaConversion);
      //pmanager->AddProcess(new G4eBremsstrahlung,   -1, 3,3);

    } else if (particleName == "e-") {
      //electron
      pmanager->AddProcess(new G4MultipleScattering,-1, 1,1);
      pmanager->AddProcess(new G4eIonisation,       -1, 2,2);
      pmanager->AddProcess(new G4eBremsstrahlung,   -1, 3,3);      

    } else if (particleName == "e+") {
      //positron
      pmanager->AddProcess(new G4MultipleScattering,-1, 1,1);
      pmanager->AddProcess(new G4eIonisation,       -1, 2,2);
      pmanager->AddProcess(new G4eBremsstrahlung,   -1, 3,3);
      pmanager->AddProcess(new G4eplusAnnihilation,  0,-1,4);

    } else if( particleName == "mu+" || 
               particleName == "mu-"    ) {
      //muon  
      pmanager->AddProcess(new G4MultipleScattering,-1, 1,1);
      pmanager->AddProcess(new G4MuIonisation,      -1, 2,2);
      pmanager->AddProcess(new G4MuBremsstrahlung,  -1, 3,3);
      pmanager->AddProcess(new G4MuPairProduction,  -1, 4,4);       

    } else if ((!particle->IsShortLived()) &&
	       (particle->GetPDGCharge() != 0.0) && 
	       (particle->GetParticleName() != "chargedgeantino")) {
      //all others charged particles except geantino
      pmanager->AddProcess(new G4MultipleScattering,-1, 1,1);
      pmanager->AddProcess(new G4hIonisation,       -1, 2,2); 

    }
  }
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

#include "G4Decay.hh"

void ExN03PhysicsList::ConstructDecay()
{
  // Add Decay Process
  G4Decay* theDecayProcess = new G4Decay();
  theParticleIterator->reset();
  while( (*theParticleIterator)() ){
    G4ParticleDefinition* particle = theParticleIterator->value();
    G4ProcessManager* pmanager = particle->GetProcessManager();
    if (theDecayProcess->IsApplicable(*particle)) { 
      pmanager ->AddProcess(theDecayProcess);
      // set ordering for PostStepDoIt and AtRestDoIt
      pmanager ->SetProcessOrdering(theDecayProcess, idxPostStep);
      pmanager ->SetProcessOrdering(theDecayProcess, idxAtRest);
    }
  }
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

void ExN03PhysicsList::SetCuts()
{
  if (verboseLevel >0){
    G4cout << "ExN03PhysicsList::SetCuts:";
    G4cout << "CutLength : " << G4BestUnit(defaultCutValue,"Length") << G4endl;
  }

  // set cut values for gamma at first and for e- second and next for e+,
  // because some processes for e+/e- need cut values for gamma
  //

G4double lowlimit=250*eV;
  G4ProductionCutsTable::GetProductionCutsTable()
    ->SetEnergyRange(lowlimit, 100.*GeV);

  // default cuts for world volume
  G4double cutValue = 1*mm;
  SetCutValue(cutValue,"gamma");
  SetCutValue(cutValue,"e-");
  SetCutValue(cutValue,"e+");

  if (verboseLevel>0) DumpCutValuesTable();
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

From my Detector Construction

I use aluminium as shield and Silicon as detector Material defined like this.

new G4Material("Aluminium", z=13., a=26.98*g/mole, density=2.70*g/cm3); new G4Material("Silicon" , z=14., a= 28.09*g/mole, density= 2.33*g/cm3);

I'm new with geant4 and don't have a clue where the mistake could be.

Thanks for any help

Kind regards

Daniel

None Re: dose depth curve  by michel maire <michel maire>,   12 Sep, 2008
Re: Question dose depth curve (Daniel Braun)
On Fri, 12 Sep 2008 13:45:02 GMT, Daniel Braun wrote:
> Hello everybody,
> 
> I tried to get a Dose depth curve in an Aluminium Sphere and compared it
> with the one I get from www.Spenvis.oma.be.
> 
> But for a thin shield I get not enough Energy deposited and for a thick
> shield I get to much Energy deposited.
> 

  You may be interested by examples/extended/electromagntic/TestEm12

       Michel

None Re: dose depth curve  by Daniel Braun <Daniel Braun>,   12 Sep, 2008
Re: None Re: dose depth curve (michel maire)
Thank you for your answer.

I had a look at the example you recommended but as I get it right, my Situation is a bit different. It is shown in the geometry file I attached in Case 3.

I'm shoot a fluence of particles ,I calculated with Spenvis, from the outside on the sphere.

And I want to get a curve like the one I calculated with Spenvis (Ionizing and non-ionizing dose models for simple geometries). I also attached the curve (sd2_dose).

I modeled the same geometry in Geant4 and shoot the same particles on it. But the result isn't the same. But I guess it should be.

Is there a way to create a model with G4 that delivers the same results as Spenvis?

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2008/09/12/09.28-98770-geometry.gif
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2008/09/12/09.28-68716-sd2_dose.jpg

None Re: dose depth curve  by Hugh Evans <Hugh Evans>,   15 Sep, 2008
Re: None Re: dose depth curve (Daniel Braun)
On Fri, 12 Sep 2008 16:46:49 GMT, Daniel Braun wrote:
> Thank you for your answer.
> 
> I had a look at the example you recommended but as I get it right, my
> Situation is a bit different. It is shown in the geometry file I
> attached in Case 3.

It must be remembered that the shieldose spherical shell method is derived from an analytical expression from the slab geometry. (See the various Shieldose references from the SPENVIS website).

Reproducing the spherical shell results is prone to difficulties.

Another difference in the simulation to consider: shieldose gives results for infinitesimally small targets (Si, SiO2, etc.). The target must be "insignificantly" small, yet you have to be able to hit it enough to get good statistics.

Additionally, the dose for the slab geometries is calculated from the shielded flux spectrum exiting the slab thickness folded with the dE/dX curve of the target - the target itself is not included in the simulation.

> 
> I'm shoot a fluence of particles ,I calculated with Spenvis, from the
> outside on the sphere.

If it is a simple result that you wish, then I'd recommend using Mulassis (also available to run on SPENVIS, and source code/local installation is available from the QinetiQ site). I've made comparable simulations to SHIELDOSE using Mulassis (particularly for protons, electrons requires some playing with the energy biasing to get a good statistical sampling of the effects of the various energy ranges).

> 
> And I want to get a curve like the one I calculated with Spenvis
> (Ionizing and non-ionizing dose models for simple geometries). I also
> attached the curve (sd2_dose).

You do realise that for the slab or spherical geometry that you have to run the complete simulation for each of the shielding thicknesses in the curve? This can be a bit tedious (and slow) :-(.

> 
> I modeled the same geometry in Geant4 and shoot the same particles on
> it. But the result isn't the same. But I guess it should be.
> 
> Is there a way to create a model with G4 that delivers the same results
> as Spenvis?
> 

Yes. but the simulation isn't an exact match to the SHIELDOSE geometry.

Regards, Hugh

None Re: dose depth curve  by Daniel Braun <Daniel Braun>,   16 Sep, 2008
Re: None Re: dose depth curve (Hugh Evans)
Thank you for your Answer.

Is there a simpler way to check the G4 results?

I have to know whether I use the right physics and the right gps settings and so on.

Thanks for your help.

Greetings

Daniel

None Re: dose depth curve  by Hugh Evans <Hugh Evans>,   17 Sep, 2008
Re: None Re: dose depth curve (Daniel Braun)
Hi Daniel,

The quickest way to get the space environment flux spectra into your simulation is to use the GPS macros created by SPENVIS for its version of Mulassis. These GPS macros you can then add to your own software (the /analysis/normalise factor must also be included to normalise the results of the simulation to those of the environment, but it may require adjustments to account for variations between the geometry of the GPS source in your own code and what's in Mulassis).

The quickest way to check that the G4 simulation is giving comparable results to SHIELDOSE is by running the SHIELDOSE slab geometry and the corresponding Mulassis Slab geometry for a given shielding thickness, you can then compare the dose results directly with the Mulassis simulation on SPENVIS.

As for the Physics: the SHIELDOSE model does include nuclear interactions for protons; for electrons the "em" physics should be sufficient; to a reasonable approximation the "em" physics is sufficient for protons as well, but you can add "binary cascade" to include nuclear interactions to the results.

Regards, Hugh

None Re: dose depth curve  by Daniel Braun <Daniel Braun>,   22 Sep, 2008
Re: None Re: dose depth curve (Hugh Evans)
Thank you very much for your answer.

I tried now to compare the results of Geant 4 and Mulassis and it matched very well.

Regards

Daniel

None SPE Primary Particles   by Steven Avery <Steven Avery>,   21 Apr, 2008

I'm using the radioprotection example but I would like to only use solar particle events (SPE) as my primary particle. The example only has ascii files for galactic cosmic rays (GCR) data. How do I set the example to only generate SPE events?

Feedback Re: SPE Primary Particles   by Giovanni Santin <Giovanni Santin>,   21 Apr, 2008
Re: None SPE Primary Particles (Steven Avery)

Dear Steven

A few suggestion:

I would recommend to use the General Particle Source (GPS) to generate your particle spectra. It's fairly simple to use, you can find a link to its detailed documentation from http://geant4.web.cern.ch/geant4/support/index.shtml

Regarding SPE spectra, it depends if you want to simulate individual solar events or the total proton fluence in a certain mission period.

For the latter, for example, you can get the total fluence predicted by the ESP model through the SPENVIS interface: http://www.spenvis.oma.be/ After you have registered (it's open and free) you look at the MULASSIS module. At the end of the user input process, you can get directly a Geant4 macro with the spectrum in GPS format.

[If you prefer to stay with the PrimaryGenerator from the radioprotection examples, you can get the ESP differential spectra from SPENVIS anyway. But I would recommend the GPS because of the many features it offers]

Please have a look as well at the 2 PPTs on "Primary particle" at http://geant4.in2p3.fr/2007/prog/prog.htm

Don't hesitate to contact me for further details

Best regards

Giovanni

Question Grazing angle proton scattering  by valentina <valentina>,   13 Feb, 2008

Hi, I have a question about the simulation of grazing angle proton scattering.

In the article:

"Low Angle Scattering of Protons on the XMM-Newton Optics and Effects on the On-Board CCD detectors"

Nartallo et al. 2001

Nartallo uses the multiple scattering to simulate the interaction of protons with a mirror reflecting surface layer (in this case XMM-Newton optics).

As a conseguence of:

"Grazing Angle Proton Scattering: effects on Chandra and XMM-Newton X-ray telescopes"

Dichter and Woolf, 2003

, where the authors show that the multiple scattering under predicts the expected proton flux at the focal plane,

Nartallo in the article:

"Update on the use of Geant4 for the simulation of low energy protons scattering off X-ray mirrors at grazing incidence angles"

implements a new physics process, G4FirsovScattering, in the G4 Monte Carlo code, to treat the scattering of low energy protons at grazing incidence angles.

Now the question is: someone knows where is G4FirsovScattering? I can't find it in G4 library!

Thanks!

Valentina

None Generating a Pulse height spectra through GEANT  Keywords: Getting a Pulse height spectra from GEANT
by rajani <rajani>,   02 Feb, 2007

Hi All!!

In a normal space experiment, the particles ( suppose photons here) interact with the detector, giving rise to the absorption or transmission of the particle. In GEANT, we can trace the physics processes it undergoes, the energy it carries after that & the step at which it does that. In a Lab- experiment, what we get out is a Pulse Height Spectra that tells the variation of no of counts with the voltage, My concern is, Can GEANT in any way tell me about the Pulse height spectra? If yes, Can you tell me how & the reference? Thanking You

Rajani

None Re: Generating a Pulse height spectra through GEANT  Keywords: Getting a Pulse height spectra from GEANT
by Maria Grazia Pia <Maria Grazia Pia>,   02 Feb, 2007
Re: None Generating a Pulse height spectra through GEANT (rajani)

Dear Rajani,

Geant4 provides tools to generate a detector response, such as, for instance, pulse height spectra. This simulation domain is called "digitisation"; the Geant4 digits_hits package is responsible for it.

I suggest you to read the corresponding sections in the Geant4 Application Developer Guide, where the details of how it works are illustrated.

You may also want to have a look at the Geant4 Advanced Example gammaray_telescope, that shows how to use the digitisation mechanism in the experimental environment of gamma-ray astronomy. You can find it in geant4/examples/advanced/gammaray_telescope.

Best wishes,

Maria Grazia Pia

Question Sunyaev-Zeldowich effect and GEANT4  Keywords: Cosmology, Astroparticle Physics
by Forough <Forough>,   22 Nov, 2006
   Hi,
   We are going to use GEANT4 in scattering of electrons
   from ionized atoms, so-called Sunyaev-Zeldowich effect
   in cosmology and astroparticle physics.
   Up to the best of our knowledge, this topic has not been
   worked until now. We are pleased to receive your comments
   about the application of GEANT4 in Sunyaev-Zeldowoch effect.
   Could you please help us? 
   Thanks if you reply.
   Sincerely,
   Forough Nasseri
Question hemisphere generation using General Particle Source Module  Keywords: hemisphere in gps
by Manju Sudhakar <Manju Sudhakar>,   28 Aug, 2006

Hi,

I would like to know how to generate a hemisphere using General Particle Source Module. It is easy to do so in the G4UserPrimaryGeneratorAction.cc, but I want to use gps because my energy is in the form of a user defined histogram. I checked the queries posted in this forum regarding generation of a hemisphere using gps, and I found out that "biasing" should be used and the extended example "exgps" has a macro "test32.g4mac, which gives the methodology to do so. But, I donot know how the biasing works and the gps manual doesnot give any details. Could someone please help me out in this.. It is really important, as I want to model the space-craft background due to photons generated on the inner surface of a hemisphere that is placed behind the space-craft, ie, the photons are incident from the hemisphere inner surface and impinging on the back of the detector.

Please could someone tell me how to go about this ??

Thanks, Manju Sudhakar.

None Physics Process to include to take care of x-ray polarization  by Manju Sudhakar <Manju Sudhakar>,   30 May, 2006

Hi,

I am working on a first step x-ray polarimeter design.I want to measure the polarization of low energy x-rays after scattering from a target. So, inorder to do that, I need to include, in the physics list a process that takes care of polarization. There is a physics process "G4LowEnergyPolarizedComptonScattering", but it is not used in any of the examples ..

And another thing is that in the http://geant4.esa.int/events/g4suw03/ site, there are a number of presentations that mention polarized photoelectric, Rayleigh scattering, pair production etc. And in the photoelectric presentation , there is a page where they show the actual track of the photon, and it is mentioned "G4LowEnergyPolarizedPhotoelectric".

I am using GEANT version 4.7.0.p01.
In the directory /geant4/geant4.7.0.p01/source/processes/electromagnetic/lowenergy/include, 
the only low energy polarization physics process is G4LowEnergyPolarizedComptonScattering
is there. Also, there is no PolarizationManager. In the paper by Ralph Dollan, Karim Laihem 
and Andreas Schalicke "Monte Carlo based studies of a polarized positron 
source for International Linear Collider (ILC)" (arXiv:physics/0512192 v1), they talk about 
polarization framework in GEANT4 .. They talk about "proposed implementation of polarized processes" 
 ... so are these yet to be implemented ?? In the latest version of GEANT, 
are these implemented ??

So, in the version of GEANT that I am using, 4.7.0.p01, the only physics process that is available is "G4LowEnergyPolarizedComptonScattering".

Could you please give me more information about the proposed implementation of polarization ? Is it already implemented ?

Thanks in advance, Manju Sudhakar.

None Re: Physics Process to include to take care of x-ray polarization  by Maria Grazia Pia <Maria Grazia Pia>,   02 Jun, 2006
Re: None Physics Process to include to take care of x-ray polarization (Manju Sudhakar)

Please see the reply to a similar posting in the Electromagnetic Processes section.

Best wishes,

Maria Grazia Pia

None Geant4 applications at IEEE NSS 2006  by Maria Grazia Pia <Maria Grazia Pia>,   29 May, 2006

Geant4 users in space applications may be interested to submit an abstract on their ongoing projects to the IEEE Nuclear Science Symposium (http://www.nss-mic.org/2006). IEEE NSS is a major conference in experimental technologies, including a Software & Computing session. This year it will take place in San Diego, the week before the SPENVIS-Geant4 Space User Workshop also hosted in California in 2006.

The official deadline for abstract submission is over, but direct submission to the conveners is still accepted.

If you are interested, please send your abstract to the Software and Computing convener (Maria.Grazia.Pia@cern.ch, with cc to nss2006@ornl.gov).

Looking forward to many exciting Geant4 results,

Maria Grazia Pia

NSS Software & Computing co-Convener

None regarding polarization in gps  by Manju Sudhakar <Manju Sudhakar>,   25 May, 2006

Hi,

This is the first time I will be simulating polarization and I'll be doing it using gps.

The command /gps/polarizarion Px Py Pz where Px, Py and Pz are the doubles that sets the polarization of the source .. Are these the Stokes parameters ?? The parameters for linear polarization, circular polarization and elliptical polarization ..So if my source photons are linearly polarized only, then the values for Px, Py and Pz would be 1,0,0 .. Is my understanding correct or is this something else ...??? These are not vectors ..but doubles .. Could you help me out ??

Regards and thanks, Manju Sudhakar

 

Question How to define the flux of particles?  Keywords: flux
by Lee Xuesheng <chaosl@pku.edu.cn>,   06 Mar, 2006

When using the geant4 in application for Space Radiation,how can I define the flux of particles(e- or gamma)? thanks

None Re: How to define the flux of particles?  by Hugh Evans <Hugh Evans>,   07 Mar, 2006
Re: Question How to define the flux of particles? (Lee Xuesheng)
Hello Lee,

I would recommend the use of the GPS module in G4 for setting up the primary
generator.

To establish a particle source you need to define:
1. the particle source surface - the surface on which the primaries are
generated
2. the angular distribution of the primaries - in space this is usually
omni-directional
3. the energy spectrum

The surface for generating the particle sources is in the most simple, a
sphere that encapsulates the model.

The angular distribution of radiation in space is generally assumed to be
isotropic or omni-directional. There are deviations from this, e.g. at low
altitudes in the South Atlantic Anomaly, during the rising phase of a solar
proton event, or astronomical events such as gamma ray bursts. For radiation
belts, solar proton event and cosmic ray analyses, though, the
omni-directional assumption is usually valid. So, the omni-directional
assumption requires a cosine-law to ensure a correct angular distribution.

If it is radiation belt or solar protons that you are trying to simulate,
then I'd recommend the SPENVIS system (http://www.spenvis.oma.be/) and it's
mulassis model implementation to generate the energy spectrum GPS macro
calls. Mulassis is a 1D general purpose Geant4 application. It will also
provide you with examples on setting up the GPS parameters.

Then there is the issue of tuning all of the above to ensure each event
produces the data you require. This can be achieved through the biasing of
the angles, energies, etc.

Regards,
Hugh

-----
H. Evans
ESA/ESTEC/TEC-EES
Postbus 299
2200 AG Noordwijk
The Netherlands

Phone:+31 (0)71 565-5109
Fax:     +31 (0)71 565-4999


Lee Xuesheng <chaosl@pku.edu.cn> wrote on 07/03/2006 08:54:08:

> *** Discussion title: Space Applications
> Email replies to space_app-g4hn@slac.stanford.edu must include:
>   In-Reply-To: <"/space_app/16"@geant4-hn.slac.stanford.edu>
>   Subject: ...change this to be about your reply.
>
> When using the geant4 in application for Space Radiation,how can I
> define the flux of particles(e- or gamma)? thanks

None Re: How to define the flux of particles?  Keywords: ISS orbit, omni-directional distribution?????
by Andres <Andres.Russu@uv.es>,   25 Mar, 2006
Re: None Re: How to define the flux of particles? (Hugh Evans)

Hello Hugh,

thank you very much for your always very useful comments!!!

As you know, I am simulating an payload (ASIM) wihich hopefully will be at a Columbus external platform one day. This instrument (MXGS) has an aperture (576 cm2) on the bottom in order to detect Transient Gamma Flashes (TGFs) from the atmosphere and also for aurora studies.

The assumption of omni-directional radiation and cosine law in a sphere is perfect for isotropic shielded structures, like ISS, but in my case I don't have the same shielding in all the instrument due to the apperture but the instrument is pointing at nadir so it has the Earth natural shielding.

Therefore, I am looking for another more accurate solution which, as my poor knowledge, will be to have a half sphere shape. What do you think? Do you know any kind of solution?

Thanks again for you and all the people who is helping me.

Regards, Andres

None Re: How to define the flux of particles?  Keywords: ISS orbit, omni-directional distribution?????
by Lee Xuesheng <chaosl@pku.edu.cn>,   05 Oct, 2006
Re: None Re: How to define the flux of particles? (Andres)

Hello Hugh, First,thanks for your answer for my question.

Now, I want to ask the question below: flux = flunce/t flunce is the sum of flux in the time t, that is flunce = flux * t How can I get the time(t) information from the Geant4? Is it the CPU time? Yes, I can get the flux from MUlassis straightly without the time. But I can not get dose rate(dose/t), if I can not get the time.

Thanks very much!

None Re: How to define the flux of particles?  by Hugh Evans <Hugh Evans>,   27 Mar, 2006
Re: None Re: How to define the flux of particles? (Andres)
Hello  Andres (and any other interested parties).

Andres <Andres.Russu@uv.es> wrote on 25/03/2006 20:38:34:

> *** Discussion title: Space Applications
> Email replies to space_app-g4hn@slac.stanford.edu must include:
>   In-Reply-To: <"/space_app/16/1/3"@geant4-hn.slac.stanford.edu>
>   Subject: ...change this to be about your reply.
>
> Hello Hugh,
>
> thank you very much for your always very useful comments!!!
>
> As you know, I am simulating an payload (ASIM) wihich hopefully will be
> at a Columbus external platform one day. This instrument (MXGS) has an
> aperture (576 cm2) on the bottom in order to detect Transient Gamma
> Flashes (TGFs) from the atmosphere and also for aurora studies.
>
> The assumption of omni-directional radiation and cosine law in a sphere
> is perfect for isotropic shielded structures, like ISS, but in my case I
> don't have the same shielding in all the instrument due to the apperture
> but the instrument is pointing at nadir so it has the Earth natural
> shielding.

To ensure there are no ambiguities, I'll break this down on particle sources:

1. For the trapped particle environment, because the trapped particles are
gyrating about the magnetic field lines and close to their mirror point there
is a strong anisotropy in the particle source distribution (see SPENVIS for a
proton model of this anisotropy). In addition, this trapping on the magnetic
field lines makes any Earth Shadow effect irrelevant. For electrons, as they
scatter well, an isotropic distribution is probably a reasonable
approximation.

2. For cosmic rays and solar protons, there is an Earth Shadow effect (which
is included in the CREME software). There is also an anisotropy from these
particles, which is due to the Earth Shadow and also a function of particle
rigidity (see Stormer theories). The Earth Shadow is a simple geometric
factor based on the solid angle subtended by the Earth. The magnetic field
induced anisotropy is a bit more complex to calculate (see ECSS-E-10-04
section 9.3.4; also available through the SPENVIS help pages). I would also
recommend L. Desorgher's MAGNETOCOSMICS package (a Geant4 application) that
can be used to model the trajectories of cosmic rays/solar protons as they
enter the magnetosphere. [if you're adventuresome, you could even try to
incorporate MAGNETOCOSMICS in your simulation - talk to Laurent about that,
though].

>
> Therefore, I am looking for another more accurate solution which, as my
> poor knowledge, will be to have a half sphere shape. What do you think?
> Do you know any kind of solution?

A very simple and basic solution for the trapped particle and solar proton
radiation would be to include an hemispherical isotropic distribution centred
over the detector opening, i.e. ignoring the effects from the back side of
the instrument - if the opening is poorly shielded compared to the backside,
then this is a valid assumption. This would give you better statistics than a
full 4PI simulation (but only by a factor of ~two) (For the cosmic rays, use
a full 4PI distribution, but scale the results by the fraction of the
detector opening that is shadowed by the Earth).

For a more accurate determination: given that there is a detector opening
angle, how well shielded is the detector outside of this acceptance angle? If
it is reasonably well shielded, then a two stage approach is probably
reasonable:

1. full isotropic (worst case scenario) distribution spectrum to confirm that
the "noise" from outside of the detector opening is acceptably negligible (if
it isn't then it gets more complicated).

2. simulate just the particle sources through the detector opening.
Initially, you could apply a simple isotropic source and see how the detector
responds. What is the solid angle opening of the detector? If it is small
enough, then you should be able to get by with ignoring the anisotropies and
just applying a global scale factor to account for them.

If the detector is exposed to space, i.e. the shielding through the detector
opening is very small in comparison to that of the remaining solid angle,
then the assumption that the energetic particle background is only from the
opening angle should be quite reasonable.

If you already have a Geant4 model of the instrument, then you could use the
Solid Sectoring Analysis Tool (SSAT) developed by QinentiQ for ESA to
evaluate the effectiveness of the shielding, i.e. the fraction of shielding
thickness as a function of solid angle, and see through which angle most of
the particles arrive.

If you don't have a model of the instrument and are only trying to get a
first approximation of the noise from radiation, then a ball park figure can
be obtained from:

      dose(*) = SUM( solid_angle(shieldthicks) * dose(shieldThicks))/(4PI)

(*) or whatever effect you've calculated as a function of 1D shielding
thickness.

Finally, despite the large shielding provided on the backside of the detector
by the space station, you can usually assume that any shielding won't really
have an effect on the cosmic ray fluxes (but you should check this anyway -
you can use a 1D simulation).

Unfortunately, putting it all together to get an anisotropic source
definition is not easily achieved. A simple software solution isn't yet
available, sorry. However, parametric runs of the configuration should give
you an estimate of whether the particle source anisotropy or shielding
anisotropy is significant in your results.

Regards
Hugh

None Re: How to define the flux of particles?  Keywords: ISS orbit, omni-directional distribution?????
by Andres <Andres.Russu@uv.es>,   25 Mar, 2006
Re: None Re: How to define the flux of particles? (Hugh Evans)

Hello Hugh,

thank you very much for your always very useful comments!!!

As you know, I am simulating an payload (ASIM) wihich hopefully will be at a Columbus external platform one day. This instrument (MXGS) has an aperture (576 cm2) on the bottom in order to detect Transient Gamma Flashes (TGFs) from the atmosphere and also for aurora studies.

The assumption of omni-directional radiation and cosine law in a sphere is perfect for isotropic shielded structures, like ISS, but in my case I don't have the same shielding in all the instrument due to the apperture but the instrument is pointing at nadir so it has the Earth natural shielding.

Therefore, I am looking for another more accurate solution which, as my poor knowledge, will be to have a half sphere shape. What do you think? Do you know any kind of solution?

Thanks again for you and all the people who is helping me.

Regards, Andres

None Untitled  by Andres <Andres.Russu@uv.es>,   06 Feb, 2006

I have two questions about spacecraft geant simulation.

1.- The number of particles. I am using gps and sphere source with spenvis histogram but I am not sure how many particles per second I have to simulate.

2.- Long term radiation. I would like to simulate long term secondary particles coming from the desactivation of the ISS materials. Do you have any idea about how to do this?

Thanks

None Re: Untitled  by Hugh Evans <Hugh Evans>,   06 Feb, 2006
Re: None Untitled (Andres)
Hello Andres,


Andres <Andres.Russu@uv.es> wrote on 06/02/2006 10:34:35:

> *** Discussion title: Space Applications
> Email replies to space_app-g4hn@slac.stanford.edu must include:
>   In-Reply-To: <"/space_app/13"@geant4-hn.slac.stanford.edu>
>   Subject: ...change this to be about your reply.
>
> I have two questions about spacecraft geant simulation.
>
> 1.- The number of particles. I am using gps and sphere source with
> spenvis histogram but I am not sure how many particles per second I have
> to simulate.

The spenvis macro files are generated for the mission fluence over the period
you specified on the orbit definition page. Thus the results from a mulassis
run on SPENVIS will give the quantities (dose, etc) for the total mission
period.

If it is the space station that you're simulating, and only looking at the
contribution from trapped protons or trapped electrons, then you should be
able to divide the results you get by the mission duration in seconds to get
the results per second as a mission average quantity. Look for the
"/analysis/normalise" macro command in the SPENVIS file, that gives the scale
factor to convert from the simulation results to environmental results.
(NOTE: spenvis/mulassis automatically accounts internally for the surface
area of the particle source sphere. If you're not running mulassis, then
you'll have to further multiply the normalisation factor by the surface area
of your sphere source).

If you're using solar protons, then it's more complicated due to the
stochastic nature of the events. You'll have to pick some events and see what
the activation is on an event by event basis (bearing in mind that you'll
have to include the geomagnetic shielding of the event).

If you mean the number of events that you need to simulate, then keep
increasing the number until your statistics are acceptable. ;-)

>
> 2.- Long term radiation. I would like to simulate long term secondary
> particles coming from the desactivation of the ISS materials. Do you
> have any idea about how to do this?

For the long term radiation, I'd investigate the time constant of the decay
that generates the long term secondary particles. If this is less than an
orbital period, then you'll need to perform your analysis for a per orbit
simulation, e.g. a trajectory crossing the SAA or the polar horns, rather
than a mission average. If, however, the decay constant is greater than a
day, then you should be able to get by using the mission average values. The
models of the trapped radiation belts are long term averages, which
simplifies the analysis - you don't have to worry about short term
(weekly/monthly) variations (if you want to, then you'll have to go to data
sets of in-situ measurements). Then, it's a matter of running your simulation
for a representative day of the mission, and calculating the activitation
from that day. From this you can then determine the long term secondary
radiation.

Regards,
Hugh

-----
H. Evans
ESA/ESTEC/TEC-EES
Postbus 299
2200 AG Noordwijk
The Netherlands

Phone:+31 (0)71 565-5109
Fax:     +31 (0)71 565-4999



None Re: Untitled  by <Andres.Russu@uv.es>,   22 Feb, 2006
Re: None Re: Untitled (Hugh Evans)
Hello Hugh,



> Hello Andres,
> 
> 
> Andres <Andres.Russu@uv.es> wrote on 06/02/2006 10:34:35:
> 
> > *** Discussion title: Space Applications
> > Email replies to space_app-g4hn@slac.stanford.edu must include:
> >   In-Reply-To: <"/space_app/13"@geant4-hn.slac.stanford.edu>
> >   Subject: ...change this to be about your reply.
> >
> > I have two questions about spacecraft geant simulation.
> >
> > 1.- The number of particles. I am using gps and sphere source with
> > spenvis histogram but I am not sure how many particles per second 
I have
> > to simulate.
> 
> The spenvis macro files are generated for the mission fluence over 
the period
> you specified on the orbit definition page. Thus the results from a 
mulassis
> run on SPENVIS will give the quantities (dose, etc) for the total 
mission
> period.
> 
> If it is the space station that you're simulating, and only looking 
at the
> contribution from trapped protons or trapped electrons, then you 
should be
> able to divide the results you get by the mission duration in 
seconds to get
> the results per second as a mission average quantity. Look for the
> "/analysis/normalise" macro command in the SPENVIS file, that gives 
the scale
> factor to convert from the simulation results to environmental 
results.
> (NOTE: spenvis/mulassis automatically accounts internally for the 
surface
> area of the particle source sphere. If you're not running mulassis, 
then
> you'll have to further multiply the normalisation factor by the 
surface area
> of your sphere source).

From the MULASSIS Software Users Manual I have learnt about the 
Normalize factor. Now, I am multiplying each bin of the histogram for 
the normalisation factor.

 
> If you're using solar protons, then it's more complicated due to the
> stochastic nature of the events. You'll have to pick some events and 
see what
> the activation is on an event by event basis (bearing in mind that 
you'll
> have to include the geomagnetic shielding of the event).

If my sphere is 5 m radius, I think I don't have to take into account 
the geomagmnetic shielding effects (they will be despreciable), Do I?
 
> If you mean the number of events that you need to simulate, then keep
> increasing the number until your statistics are acceptable. ;-)
> 

I am increasing the number until the spenvis fluence is reached. This 
point is in 7e3 particles(eg) but if I want to get the corrected 
fluence it is reached in 7e15 particles (eg) as my normalization 
factor is 1e12 (eg). So, Which is the fluence that I must reach to get 
good stadistics? 

> >
> > 2.- Long term radiation. I would like to simulate long term 
secondary
> > particles coming from the desactivation of the ISS materials. Do 
you
> > have any idea about how to do this?
> 
> For the long term radiation, I'd investigate the time constant of 
the decay
> that generates the long term secondary particles. If this is less 
than an
> orbital period, then you'll need to perform your analysis for a per 
orbit
> simulation, e.g. a trajectory crossing the SAA or the polar horns, 
rather
> than a mission average. If, however, the decay constant is greater 
than a
> day, then you should be able to get by using the mission average 
values. The
> models of the trapped radiation belts are long term averages, which
> simplifies the analysis - you don't have to worry about short term
> (weekly/monthly) variations (if you want to, then you'll have to go 
to data
> sets of in-situ measurements). Then, it's a matter of running your 
simulation
> for a representative day of the mission, and calculating the 
activitation
> from that day. From this you can then determine the long term 
secondary
> radiation.
> 
> Regards,
> Hugh
> 
> -----
> H. Evans
> ESA/ESTEC/TEC-EES
> Postbus 299
> 2200 AG Noordwijk
> The Netherlands
> 
> Phone:+31 (0)71 565-5109
> Fax:     +31 (0)71 565-4999
> 

The second point will come later.

Thank you in advance,
Andres

*****************************************
Andres Russu
Andres.Russu@uv.es
Astronomy and Space Science Group (GACE)
Ph: 0034 96 354 36 79
Fax: 0034 96 354 36 77
*****************************************




None Spacecraft activation from bkg environment  by <Andres.Russu@uv.es>,   31 Jan, 2006

Dear friends,

I am simulating a gamma instrument for the ISS. I would like to simulate how the spacecraft is getting radioactive in a long term simulation. I mean I want to take into account the particles coming form the decays of the materials around the detector plane.

Thanks in advance, Andres

Question doubt concerning the radioactive decay  Keywords: energy deposit by radioactive decay as a function of time
by Manju Sudhakar <Manju Sudhakar>,   02 Jan, 2006
Hi, 

   I would like to simulate the spallation reactions that occur CsI detectors 
due to cosmic ray protons.First I want to do an experiment on the energy deposited 
in CsI due to irradiation by a beam of monoenergetic protons, as a function of time.
I want to get the energy deposit spectrum in CsI after irradiation, as a function of time.

    I have looked at the examples/extended/radioactivity/exrdm, where the concept of 
theStep->GetPreStepPoint()->GetGlobalTime() is used.

Please, could someone help me in understanding this concept and how it is used in 
radioactive decay ????
How can I use this to get the energy deposit as a function of time since irradiation ???
Could someone please answer my query ...

With thanks, 
Manju Sudhakar.
Question doubts concerning grdm  Keywords: doubts about grdm commands
by Manju Sudhakar <Manju Sudhakar>,   29 Dec, 2005
Hi, 
  I would like to simulate the decay of induced radio-isotopes when protons 
are incident on a space-borne gamma-ray detector, cosmic-ray protons.I want 
to model the detector background.To simulate radioactive decay, we need to 
use grdm.There are some aspects about it I don't understand.

1) the command /grdm/sourceTimeProfile <filename>
    
    as given in the manual, it is for defining the "source time profile"
I donot understand ... what does this mean ?? Why is it used ?? Is it 
mandatory ?? In the extended example "radioactivity/exrdm" in geant 4.7.0, 
in one of the macros "proton-b.mac" /grdm/sourceTimeProfile beam.data is a 
command.When I opened beam.data, the file looked like this 
0  1e6
60  0

Donot understand head or tail of this ... please help me get clarified on 
this point.


2) the command /grdm/decayBiasProfile <filename>

       What about this command ?In the extended example "radioactivity/exrdm" 
in geant 4.7.0, in the macro "proton-b.mac", there is a command 
/grdm/decayBiasProfile measures.data.And, when I opened it
1000     1
1100     0
3000     1
3100     0
1e5      1
1.1e5    0

    No clue to what this file means.

Could someone please explain all this to me clearly and in detail ?

With lots and lots of advance thanks 
Manju Sudhakar.
None Re: Doubt regarding General Particle Source Module  by Hugh Evans <Hugh Evans>,   30 Aug, 2005
Hello Manju,

The energy units in the GPS histogram that you're building are in MeV. The
absolute values of the differential "flux" are not important as they are all
normalised to a probability distribution [0..1], therefore the relative
difference between bins in the histogram are of the greatest importance, not
the absolute value.

While cosmic ray fluxes aren't yet available, the trapped proton, trapped
electron and solar proton flux/fluence spectra from SPENVIS
(http://www.spenvis.oma.be/spenvis/) can be converted to GPS macros via its
Mulassis application.  By playing with this, you can easily determine how the
environmental spectra are converted to the GPS macro commands.

Alternatively, I can also send you an Excel spreadsheet within which the
CREME-86 spectra are implemented and the GPS macros are formed.

Regards,
Hugh

-----
H. Evans
ESA/ESTEC/TEC-EES
Postbus 299
2200 AG Noordwijk
The Netherlands

Phone:+31 (0)71 565-5109
Fax:     +31 (0)71 565-4999



|---------+--------------------------->
|         |           Manju Sudhakar  |
|         |           <manjus@isac.ern|
|         |           et.in>          |
|         |                           |
|         |           30/08/2005 09:25|
|         |                           |
|---------+--------------------------->
  >--------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                          |
  |        To:      space_app-g4hn@slac.stanford.edu                                                                         |
  |        cc:                                                                                                               |
  |        Subject: Doubt regarding General Particle Source Module                                                           |
  >--------------------------------------------------------------------------------------------------------------------------|




*** Discussion title: Space Applications
Email replies to space_app-g4hn@slac.stanford.edu must include:
  In-Reply-To: <"/space_app/3"@geant4-hn.slac.stanford.edu>
  Subject: ...change this to be about your reply.

Dear GEANT users ,

I have a doubt regarding one of the commands in General Particle Source
Module.

I have constructed a detector system mounted on a space platform, and I
wish to irradiate it with cosmic-ray protons, at 1AU.I have the spectrum
of the protons with me and I have to enter the energy and flux as a
user-defined arbitrary point-wise function of the form, /gps/ene/type
Arb /gps/hist/type arb /gps/hist/point ...(energy) ... (flux) .... ....
.... .... /gps/hist/inter Lin /run/beamOn 100000

        This is fine, but my doubts are as follows ,
1) What is the default value of the energy points ? Is it MeV ?
2) What is the default value of the differential flux to be entered as in the

   second column ?

Could you please answer my doubts. Regards, Manju Sudhakar.





None Re: Doubt regarding General Particle Source Module  by Andres <Andres.Russu@uv.es>,   28 Sep, 2005
Re: None Re: Doubt regarding General Particle Source Module (Hugh Evans)

Dear Hugh,

I am very interested inthe Excel Spreadsheet to convert Creme86 to GPS macros, In fact, I am using Creme96 Do you have also the spreadsheet for this version?

Best regards, Andres

Question Doubt regarding General Particle Source Module  Keywords: units of differential spectrum in gps.
by Manju Sudhakar <manjus@isac.ernet.in>,   30 Aug, 2005

Dear GEANT users ,

I have a doubt regarding one of the commands in General Particle Source Module.

I have constructed a detector system mounted on a space platform, and I wish to irradiate it with cosmic-ray protons, at 1AU.I have the spectrum of the protons with me and I have to enter the energy and flux as a user-defined arbitrary point-wise function of the form, /gps/ene/type Arb /gps/hist/type arb /gps/hist/point ...(energy) ... (flux) .... .... .... .... /gps/hist/inter Lin /run/beamOn 100000

        This is fine, but my doubts are as follows ,
1) What is the default value of the energy points ? Is it MeV ?
2) What is the default value of the differential flux to be entered as in the 
   second column ? 

Could you please answer my doubts. Regards, Manju Sudhakar.

None Geant4 Space Users Workshop  by Makoto Asai <Makoto Asai>,   02 Jun, 2005
Dear colleague,

On 3-7 October 2005, a combined workshop for the SPENVIS and 
GEANT4 Space applications communities will be held in the 
historic university town of Leuven, Belgium. The workshop venue 
is the Faculty Club of the Catholic University, situated in the 
beautifully restored Grand Beguinage, a UNESCO World Heritage 
Site.

The SPENVIS workshop will take place on 3-4 Oct, the Geant4 
workshop will follow on 6-7 Oct, with a joint session in the 
morning of 5 Oct.

The SPENVIS workshop is the second in a series that started at 
ESTEC in 2002. The emphasis during the SPENVIS workshop will 
be on user experience and requirements for future developments. 
We aim for an informal workshop with a limited number of 
presentations (and a poster session) which can serve as starting 
points for round table discussions addressing specific
developments and applications. The programme is deliberately 
kept open to allow users to actively participate in the 
organisation. If you have inputs or suggestions for the workshop 
programme, please send a note to D.Heynderickx@oma.be .

Several GEANT4 based radiation effects packages are now available 
or under development, which are or will be implemented in the 
SPENVIS user interface. In view of these developments, we opted 
for a combined workshop where users and developers of both 
communities can meet and interact.

The GEANT4 Space Users' workshop follows the events organised 
at ESTEC in 2003 and Vanderbilt University in 2004. The focus 
will be on new results for component, sensor, and shielding 
analyses, as well as on developments for Exploration and Science 
missions. Users are invited to highlight new requirements based 
on their applications.

Registration is now open at:
 http://www.spenvis.oma.be/spenvis/workshop/workshop.html 
Workshop participants are invited to submit abstracts before 
1st September, via e-mail attachment in pdf format to 
D.Heynderickx@oma.be . Please indicate for which part of the 
workshop you are submitting, and your preference for oral or 
poster presentation (subject to the final decision of the 
scientific committee). Abstracts and a more detailed programme
will be put on-line when available.

More information on SPENVIS and GEANT4 space applications can 
be found at
 http://www.spenvis.oma.be/ 
and
 http://geant4.esa.int/ 
respectively.


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