source: trunk/source/processes/hadronic/models/neutron_hp/src/G4NeutronHPIsotropic.cc @ 1340

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//
// neutron_hp -- source file
// J.P. Wellisch, Nov-1996
// A prototype of the low energy neutron transport model.
//
#include "G4NeutronHPIsotropic.hh"
#include "Randomize.hh"
#include "G4Gamma.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4Neutron.hh"
#include "G4Proton.hh"
#include "G4Deuteron.hh"
#include "G4Triton.hh"
#include "G4He3.hh"
#include "G4Alpha.hh"

void G4NeutronHPIsotropic::Init(std::ifstream & )
{
}

G4ReactionProduct * G4NeutronHPIsotropic::Sample(G4double anEnergy, G4double massCode, G4double )
{
   G4ReactionProduct * result = new G4ReactionProduct;
   G4int Z = static_cast<G4int>(massCode/1000);
   G4int A = static_cast<G4int>(massCode-1000*Z);

   if(massCode==0)
   {
     result->SetDefinition(G4Gamma::Gamma());
   }
   else if(A==0)
   {
     result->SetDefinition(G4Electron::Electron());     
     if(Z==1) result->SetDefinition(G4Positron::Positron());
   }
   else if(A==1)
   {
     result->SetDefinition(G4Neutron::Neutron());
     if(Z==1) result->SetDefinition(G4Proton::Proton());
   }
   else if(A==2)
   {
     result->SetDefinition(G4Deuteron::Deuteron());      
   }
   else if(A==3)
   {
     result->SetDefinition(G4Triton::Triton());  
     if(Z==2) result->SetDefinition(G4He3::He3());
   }
   else if(A==4)
   {
     result->SetDefinition(G4Alpha::Alpha());
     if(Z!=2) throw G4HadronicException(__FILE__, __LINE__, "Unknown ion case 1");    
   }
   else
   {
     throw G4HadronicException(__FILE__, __LINE__, "G4NeutronHPIsotropic: Unknown ion case 2");
   }

   G4double cosTh = G4UniformRand();
   G4double phi = twopi*G4UniformRand();
   G4double theta = std::acos(cosTh);
   G4double sinth = std::sin(theta);
   
// we need the the Q value of the reaction
   result->SetKineticEnergy(std::max(0.001*MeV, anEnergy+GetQValue()));
   G4double mtot = result->GetTotalMomentum(); 
   G4ThreeVector tempVector(mtot*sinth*std::cos(phi), mtot*sinth*std::sin(phi), mtot*std::cos(theta) );
   result->SetMomentum(tempVector);

   return result;
}