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Question Wrong gamma ray lines from HP neutron inelastic interactions 

Keywords: neutron inelastic HP
Forum: Hadronic Processes
Date: 16 Oct, 2006
From: Guez <Guez>

Hi,
I'm trying to simulate the gamma resulting from interaction of 14 MeV 
neutrons with lights nucleus.
I'm facing problem, which could be a bug in the G4NDL database, but 
I'm not sure to understand it well.
So, the problem is that, the gamma ray that I observe corresponds to 
existing excitation level of the target nucleus, but the relative 
intensities are not those I'm expect for.
For exemple, with a 12C nucleus, I observe the expected 4.43 MeV 
gamma ray, but also 4 other rays (@ 8.268, 9.637, 12.70 and 15.100 MeV).
The 15.1 MeV would, moreover, not exist at all, since its energy is 
higher than the 14.1 MeV incident neutron energy.
However, as you can see in the attached text, which corresponds to one 
such spurious event, as written when I set /tracking/verbose 1, this 
kind of event really occurs.
I must do something wrong, because this kind of problems 
(wrong gamma ray lines) occurs not only with 12C carbon, but
with other common nucleus (namely 16O, 27Al)
For information, to draw energy spectrum from neutron inelastic,
I've created a G4UserTrackingAction with the followin
PreTrackingAction:

{if (track->GetDefinition()->GetPDGEncoding()==22 
   && track->GetParentID==1
   && track->GetCreatorProcess()->GetProcessName()=="NeutronInelastic"))
cout<<track->GetKinetikEnergy()/MeV
}

I've tried G48.0p01 and 8.1p01 and with G4NDL version 3.7, 3.8 and 3.9
I also used all the XXX_HP physics list availables, and also my own
physic list, with only protons, alpha, neutrons, ions particles
and only G4NeutronHPorLEInelasticModel built... but the results
are always the same...
Can anybody halps me with it ?
Thnaks in advance...


 D. Guez

# generating event 227

*********************************************************************************************************
* 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        0        0     -500      14.1        0        0         0 world_physical initStep
    1        0        0     -100      14.1        0      400       400 target_physical Transportation
    2        0        0    -10.4      14.1        0     89.6       490 target_physical LElastic

*********************************************************************************************************
* G4Track Information:   Particle = C12[0.0],   Track ID = 2,   Parent ID = 1
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng  NextVolume ProcName
    0        0        0    -10.4    0.0169        0        0         0 target_physical initStep
    1 -4.89e-05 6.51e-05    -10.4         0   0.0169 0.000107  0.000107 target_physical ionIoni

*********************************************************************************************************
* 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
    2        0        0    -10.4      14.1        0        0       490 target_physical initStep
    3     3.48    -4.62     37.9         0        0     48.7       538 target_physical NeutronInelastic

*********************************************************************************************************
* G4Track Information:   Particle = gamma,   Track ID = 5,   Parent ID = 1
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng  NextVolume ProcName
    0     3.48    -4.62     37.9      15.1        0        0         0 target_physical initStep
    1     58.4    -87.3      100      15.1        0      117       117 world_physical Transportation
    2      665   -1e+03      785      15.1        0 1.29e+03  1.41e+03  OutOfWorld Transportation

*********************************************************************************************************
* G4Track Information:   Particle = C12[0.0],   Track ID = 4,   Parent ID = 1
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng  NextVolume ProcName
    0     3.48    -4.62     37.9     0.098        0        0         0 target_physical initStep
    1     3.48    -4.62     37.9         0    0.098 0.000356  0.000356 target_physical ionIoni

*********************************************************************************************************
* G4Track Information:   Particle = neutron,   Track ID = 3,   Parent ID = 1
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng  NextVolume ProcName
    0     3.48    -4.62     37.9     0.819        0        0         0 target_physical initStep
    1    -5.71     3.82      100     0.819        0     63.3      63.3 world_physical Transportation
    2     -139      126    1e+03     0.819        0      918       981  OutOfWorld Transportation

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