NeutronSource/src/PrimaryGeneratorAction.cc

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0025 //
0026 /// \file PrimaryGeneratorAction.cc
0027 /// \brief Implementation of the PrimaryGeneratorAction class
0028 //
0029 //
0030 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0031 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0032
0033 #include "PrimaryGeneratorAction.hh"
0034
0035 #include "DetectorConstruction.hh"
0036
0037 #include "G4Event.hh"
0038 #include "G4Geantino.hh"
0039 #include "G4IonTable.hh"
0040 #include "G4ParticleDefinition.hh"
0041 #include "G4ParticleTable.hh"
0042 #include "G4PhysicalConstants.hh"
0043 #include "G4SystemOfUnits.hh"
0044 #include "Randomize.hh"
0045
0046 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0047
0048 PrimaryGeneratorAction::PrimaryGeneratorAction(DetectorConstruction* det) : fDetector(det)
0049 {
0050   G4int n_particle = 1;
0051   fParticleGun = new G4ParticleGun(n_particle);
0052
0053   fParticleGun->SetParticleEnergy(0 * eV);
0054   fParticleGun->SetParticlePosition(G4ThreeVector(0., 0., 0.));
0055   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
0056 }
0057
0058 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0059
0060 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0061 {
0062   delete fParticleGun;
0063 }
0064
0065 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0066
0067 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0068 {
0069   // particle type
0070   if (fParticleGun->GetParticleDefinition() == G4Geantino::Geantino()) {
0071     G4int Z = 95, A = 241;
0072     G4double ionCharge = 0. * eplus;
0073     G4double excitEnergy = 0. * keV;
0074
0075     G4ParticleDefinition* ion = G4IonTable::GetIonTable()->GetIon(Z, A, excitEnergy);
0076     fParticleGun->SetParticleDefinition(ion);
0077     fParticleGun->SetParticleCharge(ionCharge);
0078   }
0079
0080   // vertex position uniform within the absorber
0081   //
0082   G4double Rmax = fDetector->GetAbsorRadius();
0083   G4double Rmax2 = Rmax * Rmax;
0084   G4double R2 = G4UniformRand() * Rmax2;
0085   G4double R = std::sqrt(R2);
0086
0087   G4double phi = twopi * G4UniformRand();
0088   G4double ux = R * std::cos(phi), uy = R * std::sin(phi);
0089   G4double uz = (fDetector->GetAbsorLength()) * (G4UniformRand() - 0.5);
0090
0091   fParticleGun->SetParticlePosition(G4ThreeVector(ux, uy, uz));
0092
0093   // distribution uniform in solid angle
0094   //
0095   G4double cosTheta = 2 * G4UniformRand() - 1.;
0096   G4double sinTheta = std::sqrt(1. - cosTheta * cosTheta);
0097   phi = twopi * G4UniformRand();
0098   G4double vx = sinTheta * std::cos(phi), vy = sinTheta * std::sin(phi), vz = cosTheta;
0099
0100   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(vx, vy, vz));
0101
0102   fParticleGun->GeneratePrimaryVertex(anEvent);
0103 }
0104
0105 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......