Message: Neither QGSP_BERT_HP or QGSP_BIC_HP work Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

News Neither QGSP_BERT_HP or QGSP_BIC_HP work 

Forum: Hadronic Processes
Re: Warning Neutron Capture bug? Too many gammas (Manuel Julien)
Date: 10 May, 2011
From: Manuel Julien <Manuel Julien>

Hi,

Thanks to both of you for your help. I've tried the QGSP_BERT_HP and QGSP_BIC_HP reference physics
lists, but neither gets the 11.45 MeV de-excitation energy right. To recap, in the 10B + n -> 11B*
reaction, the 11B* has 11.45 MeV to release. Here is one example from each physics list.

QGSP_BIC_HP

*********************************************************************************************************
* G4Track Information:   Particle = neutron,   Track ID = 1,   Parent ID = 0
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng  NextVolume ProcName
    0     -500        0        0   2.5e-08        0        0         0       World initStep
    1      -50        0        0   2.5e-08        0      450       450    10B_Cube Transportation
    2      -50        0        0         0        0  0.00788       450    10B_Cube nCapture
    :----- List of 2ndaries - #SpawnInStep=  5(Rest= 0,Along= 0,Post= 5), #SpawnTotal=  5 ---------------
    :       -50         0         0      8.92              gamma
    :       -50         0         0      7.01              gamma
    :       -50         0         0      4.45              gamma
    :       -50         0         0      2.54              gamma
    :       -50         0         0   0.00763           B11[0.0]
    :----------------------------------------------------------------- EndOf2ndaries Info ---------------

Total : 22.92 MeV (Twice too much exactly)

QGSP_BERT_HP

*********************************************************************************************************
* G4Track Information:   Particle = neutron,   Track ID = 1,   Parent ID = 0
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng  NextVolume ProcName
    0     -500        0        0   2.5e-08        0        0         0       World initStep
    1      -50        0        0   2.5e-08        0      450       450    10B_Cube Transportation
    2      -50        0        0         0        0  0.00254       450    10B_Cube nCapture
    :----- List of 2ndaries - #SpawnInStep=  7(Rest= 0,Along= 0,Post= 7), #SpawnTotal=  7 ---------------
    :       -50         0         0      8.92              gamma
    :       -50         0         0      7.01              gamma
    :       -50         0         0      4.45              gamma
    :       -50         0         0      4.45              gamma
    :       -50         0         0      4.44              gamma
    :       -50         0         0       2.3              gamma
    :       -50         0         0   0.00408           B11[0.0]
    :----------------------------------------------------------------- EndOf2ndaries Info ---------------

Total : 31.57 MeV

The project from which I got those results is most simplistic (6 files). The world is a 2m cube of
vacuum, the "detector" is a 10cm cube of Boron 10. The generator shoots 0.025 eV neutrons from
(-0.5m,0,0) in the x direction. The physics is either QGSP_BERT_HP or QGSP_BIC_HP.

As for reference physics lists, I've found a "Space Science Physics List" supported by SLAC :

http://www.slac.stanford.edu/comp/physics/geant4/slac_physics_lists/space/physlistdoc.html

Tatsumi Koi's name is at the bottom of the page. The page dates from 2008-08, so I had to modify a
few things : change G4MultipleScattering to G4eMultipleScattering, G4MuMultipleScattering and
G4hMultipleScattering, I've put the LowEM models because I'm in the Compton telescope business
(~0.5-30MeV) while Fermi's LAT is a pair production telescope, and put the BIC model for the neutron
and proton background. I'll also see what I can do with Andreas Zoglauer's Megalib & Cosima.

Manuel

 Add Message Add Message
to: "Neither QGSP_BERT_HP or QGSP_BIC_HP work"

 Subscribe Subscribe

This site runs SLAC HyperNews version 1.11-slac-98, derived from the original HyperNews


[ Geant 4 Home | Geant 4 HyperNews | Search | Request New Forum | Feedback ]