|Message: Elastic neutron scattering in QGSP_BERT_HP||Not Logged In (login)|
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I am simulating a 3He neutron detector that is surrounded by polyethylene. The goal is for the polyethylene to moderate fast neutrons to thermal energies, when they subsequently capture on 3He in the detector producing a proton and triton. It is therefore important that the physics models that I use can reliably simulate neutrons from a few MeV to thermal energies. The first question is: are there any reference physics lists that are recommended for this purpose? If I write my own physics list for the neutrons, what models are recommended?
Secondly, I tried using the QGSP_BERT_HP physics list, but I noticed that the neutrons were not interacting in the polyethylene as expected. The dominant interaction for neutrons in polyethylene should be elastic scattering on hydrogen, but this process did not appear to be occurring (see hadronic process summary for neutrons below). I was able to write my own version of QGSP_BERT_HP with elastic scattering on, but is elastic neutron scattering really turned off in QGSP_BERT_HP? Is it possible that this behavior is indicative of another problem with my geant4 installation? I am using version 9.5.p01. Thanks!
Hadronic Processes for <neutron> ----------------------------------- NeutronInelastic Models: FTFP: Emin(GeV)= 4 Emax(GeV)= 100000 BertiniCascade: Emin(GeV)= 0.0199 Emax(GeV)= 5 NeutronHPInelastic: Emin(GeV)= 0 Emax(GeV)= 0.02
NeutronInelastic Crs sctns: : Emin(GeV)= 0 Emax(GeV)= 100000 Barashenkov-Glauber: Emin(GeV)= 0 Emax(GeV)= 100000 NeutronHPInelasticXS: Emin(GeV)= 0 Emax(GeV)= 0.02 G4CrossSectionPairGG: Emin(GeV)= 0 Emax(GeV)= 100000 G4CrossSectionPairGG: Wellisch-Laidlaw cross sections below 91 GeV, Glauber-Gribov above GheishaInelastic: Emin(GeV)= 0 Emax(GeV)= 100000
nCapture Models: G4LCapture: Emin(GeV)= 0.0199 Emax(GeV)= 20000 NeutronHPCapture: Emin(GeV)= 0 Emax(GeV)= 0.02
nCapture Crs sctns: NeutronHPCaptureXS: Emin(GeV)= 0 Emax(GeV)= 0.02 GheishaCaptureXS: Emin(GeV)= 0 Emax(GeV)= 100000
nFission Models: G4LFission: Emin(GeV)= 0.0199 Emax(GeV)= 20000 NeutronHPFission: Emin(GeV)= 0 Emax(GeV)= 0.02
nFission Crs sctns: NeutronHPFissionXS: Emin(GeV)= 0 Emax(GeV)= 0.02 GheishaFissionXS: Emin(GeV)= 0 Emax(GeV)= 100000
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