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Forum: Hadronic Processes
Re: Question Radioactive decay - isomers... (Michael)
Date: 13 Jun, 2012
From: Michael <Michael>

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Hi Vladimir,

I was pretty dumb to use a 20 MeV source in the forum question sorry: I've
actually tried the threshold ~13.5 MeV all the way up to 20 MeV the ~upper
limit of the HP physics and always get the ground state of Al-26!

Note that I'm using 4_9_4_p02 on linux...
I couldn't see your response anywhere on the forum recent posting so I
emailed back direct but I'll copy the contents to the forum for public
interest.

Thanks,

Mike.
On Wed, Jun 13, 2012 at 2:30 PM, Vladimir IVANTCHENKO <vnivanch@mail.cern.ch
> wrote:

>
> Hello,
>
> Try to run with 18 MeV beam - in that case HP physics will be always used.
> If the result will be the same your question will be exactly to the HP
> model.
>
> VI
>
> On Wed, 13 Jun 2012, Michael wrote:
>
>
>> *** Discussion title: Hadronic Processes
>>
>> Hi,
>>
>> I'm using the QGSP_BERT_HP physics list together with the
>> ->RegisterPhysics(new G4RadioactivedecayPhysics()) command...
>>
>> After registering G4RadioactivedecayPhysics I decided to try a simple
>> example of n,2n on Al-27 for 20 MeV neutron. Evaluated cross sections
>> exist for populating the 0+ excited state (which B+ decays in 6.345s)
>> and the 5+ ground state (which B+ decays in 7.1e5yrs together with a
>> ~1.8 MeV gamma). I should see both states populated but only see the
>> ground state...is it using a total cross section but only populating the
>> ground state or is the iomeric final state completely omitted?
>>
>> I tink the question I'm asking is: does Geant4 handle isomers and
>> metastable excited states following hadronic reactions? With regard to
>> shielding calculations etc this is a pretty important result. For
>> example if I believe the current result I would be led to believe that
>> the aluminium would be ~inert (7.1e5year b+ decay) following 20 MeV
>> bombardment...in reality it would be pretty active due to the 6.345s
>> isomer?
>>
>> If Geant4 could do this properly it would save me a whole world of pain
>> trying to post process activation data?
>>
>> Thoughts?
>>
>> Cheers,
>>
>> Mike.
>>
>> ------------------------------**------------------------------**-
>> Visit this GEANT4 at hypernews.slac.stanford.edu message (to reply or
>> unsubscribe) at:
>> http://hypernews.slac.**stanford.edu/HyperNews/geant4/**
>> get/hadronprocess/1253.html<http://hypernews.slac.stanford.edu/HyperNews/geant4/get/hadronprocess/1253.html>
>>
>>


-- 
*Mike Rubery MPhys*
*Fusion Diagnostics Physicist*
*The University of Leicester*
*University Road*
*Leicester*
*LE1 7RH*
**
*MOB :: 07748861686*

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<div>Hi Vladimir,</div>
<div>=A0</div>
<div>I was pretty dumb to use a 20 MeV source in the forum question sorry: =
I&#39;ve actually tried the threshold ~13.5 MeV all the way up to 20 MeV th=
e ~upper limit of the HP physics and always get the ground state of=A0Al-26=
!</div>

<div>=A0</div>
<div>Note that I&#39;m using 4_9_4_p02 on linux...<br></div>
<div>I couldn&#39;t see your response anywhere on the forum recent posting =
so I emailed back direct but I&#39;ll copy the contents to the forum for pu=
blic interest.</div>
<div>=A0</div>
<div>Thanks,</div>
<div>=A0</div>
<div>Mike.<br></div>
<div class=3D"gmail_quote">On Wed, Jun 13, 2012 at 2:30 PM, Vladimir IVANTC=
HENKO <span dir=3D"ltr">&lt;<a href=3D"mailto:vnivanch@mail.cern.ch" target=
=3D"_blank">vnivanch@mail.cern.ch</a>&gt;</span> wrote:<br>
<blockquote style=3D"BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PA=
DDING-LEFT:1ex" class=3D"gmail_quote"><br>Hello,<br><br>Try to run with 18 =
MeV beam - in that case HP physics will be always used. If the result will =
be the same your question will be exactly to the HP model.<br>
<br>VI<br><br>On Wed, 13 Jun 2012, Michael wrote:<br><br>
<blockquote style=3D"BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PA=
DDING-LEFT:1ex" class=3D"gmail_quote"><br>*** Discussion title: Hadronic Pr=
ocesses<br><br>Hi,<br><br>I&#39;m using the QGSP_BERT_HP physics list toget=
her with the<br>
-&gt;RegisterPhysics(new G4RadioactivedecayPhysics()) command...<br><br>Aft=
er registering G4RadioactivedecayPhysics I decided to try a simple<br>examp=
le of n,2n on Al-27 for 20 MeV neutron. Evaluated cross sections<br>exist f=
or populating the 0+ excited state (which B+ decays in 6.345s)<br>
and the 5+ ground state (which B+ decays in 7.1e5yrs together with a<br>~1.=
8 MeV gamma). I should see both states populated but only see the<br>ground=
 state...is it using a total cross section but only populating the<br>groun=
d state or is the iomeric final state completely omitted?<br>
<br>I tink the question I&#39;m asking is: does Geant4 handle isomers and<b=
r>metastable excited states following hadronic reactions? With regard to<br=
>shielding calculations etc this is a pretty important result. For<br>examp=
le if I believe the current result I would be led to believe that<br>
the aluminium would be ~inert (7.1e5year b+ decay) following 20 MeV<br>bomb=
ardment...in reality it would be pretty active due to the 6.345s<br>isomer?=
<br><br>If Geant4 could do this properly it would save me a whole world of =
pain<br>
trying to post process activation data?<br><br>Thoughts?<br><br>Cheers,<br>=
<br>Mike.<br><br>------------------------------<u></u>---------------------=
---------<u></u>-<br>Visit this GEANT4 at <a href=3D"http://hypernews.slac.=
stanford.edu/" target=3D"_blank">hypernews.slac.stanford.edu</a> message (t=
o reply or unsubscribe) at:<br>
<a href=3D"http://hypernews.slac.stanford.edu/HyperNews/geant4/get/hadronpr=
ocess/1253.html" target=3D"_blank">http://hypernews.slac.<u></u>stanford.ed=
u/HyperNews/geant4/<u></u>get/hadronprocess/1253.html</a><br><br></blockquo=
te>
</blockquote></div><br><br clear=3D"all"><br>-- <br>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>Mike Rubery MP=
hys</strong></font></div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>Fusion Diagnos=
tics Physicist</strong></font></div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>The University=
 of Leicester</strong></font></div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>University Roa=
d</strong></font></div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>Leicester</str=
ong></font></div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>LE1 7RH</stron=
g></font></div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong></strong></fon=
t>=A0</div>
<div><font color=3D"#3333ff" face=3D"garamond,serif"><strong>MOB :: 0774886=
1686</strong></font></div><br>

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