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Question Energy range for a specific element 

Keywords: Energy range Hydrogen element
Forum: Physics List
Date: 05 Mar, 2007
From: Antony Luk <antonyluk@cuhk.edu.hk>

I would like to use G4LEnp model for the elastic scattering process of neutron above 20MeV with hydrogen. Here is the code:

 G4HadronElasticProcess* theHadronElasticProcess = new G4HadronElasticProcess();
 G4LElastic* theNeutronLElastic = new G4LElastic();
 G4NeutronHPElastic* theNeutronHPElastic = new G4NeutronHPElastic();
 theNeutronHPElastic->SetMaxEnergy( 20.*MeV );

 theNeutronLElastic->SetMinEnergy( 20.*MeV );
 theNeutronLElastic->SetMaxEnergy( 10.*TeV );
 theNeutronLElastic->SetMaxEnergy( 0.*MeV, G4Element::GetElement("Hydrogen"));

 G4LEnp* theNPElastic = new G4LEnp();
 theNPElastic->SetMinEnergy(0.*MeV);
 theNPElastic->SetMaxEnergy(0.*MeV);
 theNPElastic->SetMinEnergy(20.*MeV, G4Element::GetElement("Hydrogen"));
 theNPElastic->SetMaxEnergy(1200.*GeV, G4Element::GetElement("Hydrogen"));
 theNPElastic->SetVerboseLevel(2);

 theHadronElasticProcess->RegisterMe( theNeutronHPElastic );
 theHadronElasticProcess->RegisterMe( theNeutronLElastic );
 theHadronElasticProcess->RegisterMe( theNPElastic);

 pManager->AddDiscreteProcess( theHadronElasticProcess );

The code works well for pure Hydrogen. However, if I use compound with Hydrogen. For example, water:

 G4Material* H2O = new G4Material("Water", density= 1.000*g/cm3, ncomponents=2);
 H2O->AddElement(H, natoms=2);
 H2O->AddElement(O, natoms=1);
 H2O->GetIonisation()->SetMeanExcitationEnergy(75*eV);

I found that G4LEnp model was also used to treat neutron scattering with Oxygen:

G4LEnp:ApplyYourself: incident particle: neutron
P = 0.238808 GeV/c, Px = 0 GeV/c, Py = 1.42109e-17 GeV/c, Pz = 0.238808 GeV/c
E = 0.969439 GeV, kinetic energy = 0.0298737 GeV, mass = 0.939566 GeV, charge = 0
G4LEnp:ApplyYourself: material:
A = 16, Z = 8, atomic mass 0.938272GeV
G4LEnp:ApplyYourself: total:
E = 1.90771 GeV, mass = 1.89271 GeV, charge = 8
sample=0.0107902
0 179 8e-05 0
0 89 8e-05 0.487081
0 44 8e-05 0.148691
0 22 8e-05 0.0414206
0 11 8e-05 0.0114909
5 11 0.00288773 0.0114909
8 11 0.00648482 0.0114909
9 11 0.00800356 0.0114909
10 11 0.00967217 0.0114909
   energy bin 1 energy=0.02
   angle bin 10.6147 angle=11.1147
  E1, M1 (GeV) 0.969439 0.939566
  E2, M2 (GeV) 0.939566 0.939566
  particle  1 momentum in CM 0 7.04961e-18 0.118466 0.118466
  AFTER SCATTER...
  particle 1 momentum in CM 0.00777607 0.0214725 0.116244 0.118466
  betaCM 0 7.44412e-18 0.125095 0.125095
  gammaCM 1.00792
  particle 1 momentum in LAB (0.00777607,0.0214725,0.236568) 0.237668
  particle 2 momentum in LAB (-0.00777607,-0.0214725,0.00223964) 0.0229467
  TOTAL momentum in LAB (1.43618e-15,3.98259e-15,0.238808) 0.238808

The situation is same for other compounds: Once the compound has hydrogen in it, G4LEnp will be used to treat the scattering of neutron with the nuclei of that molecule. Is it a bug or I did something wrong? Thank you very much for you help.

Antony Luk

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1 None: Re: Energy range for a specific element   (Vladimir IVANTCHENKO - 05 Mar, 2007)
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