_Geant4 Version:geant4-11-01-ref-00
_Operating System: linux lxplus
_Compiler/Version: gcc 12.1
Dear experts/users,
I’m developing simulations to study the deposited energy distributions of gammas produced by neutron captures on natural liquid argon. The simulations run fine and I get most of the gammas that I supposed to get. However the energy spectrum show major discrepancies with respect to the expected intensities.
To understand what is going on I’m using the Hadr03 example and G4_lAr as material I obtain this energy spectrum for 100k thermal neutron captures:
The highest intensity corresponds to the 167 keV gamma, but the value is about 38k instead of ~80k (100k thermal neutrons simulated). The other lines with about 50% of probability are 4745 keV and 1187 keV, but we have only ~40k for the 1187 line and only 6k for the 4745. So in some cases a factor ~2 and in other a higher discrepancy.
I’m using the Hadr03 example with G4HadronPhysicsFTFP_BERT_HP. This is what is printed for the relevant options:
UseOnlyPhotoEvaporation ? 1
SkipMissingIsotopes ? 0
NeglectDoppler ? 0
DoNotAdjustFinalState ? 1
ProduceFissionFragments ? 0
UseWendtFissionModel ? 0
UseNRESP71Model ? 0
Any idea of what could be the problem?
Attached the expected intensities for Ar40 and Ar36.
ng_E_thermal.pdf (55.1 KB)
ng_pol_n_g_E_thermal.pdf (55.3 KB)
Thanks in advance!
Luis
The test_lAr.mac look like this:
Macro file for “Hadr03.cc”
/control/verbose 1
/run/verbose 1
/testhadr/det/setMat G4_lAr
/testhadr/det/setSize 1000 m
/process/had/verbose 1
/process/em/verbose 0
/run/initialize
/gun/particle neutron
/gun/energy 25 meV
/process/list
/process/inactivate hadElastic
/analysis/setFileName nCapture
/analysis/h1/set 2 1000 0. 10 MeV #gamma
/analysis/h1/set 8 100 0. 70 keV #nuclei
/analysis/h1/set 11 100 0. 70 MeV #Q
/analysis/h1/set 12 100 0. 15 MeV #Pbalance
/run/printProgress 10000
/run/beamOn 100000
