OpNovice2/src/PrimaryGeneratorAction.cc

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0025 //
0026 /// \file PrimaryGeneratorAction.cc
0027 /// \brief Implementation of the PrimaryGeneratorAction class
0028
0029 #include "PrimaryGeneratorAction.hh"
0030
0031 #include "PrimaryGeneratorMessenger.hh"
0032
0033 #include "G4Event.hh"
0034 #include "G4OpticalPhoton.hh"
0035 #include "G4ParticleDefinition.hh"
0036 #include "G4ParticleGun.hh"
0037 #include "G4ParticleTable.hh"
0038 #include "G4SystemOfUnits.hh"
0039 #include "Randomize.hh"
0040
0041 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0042
0043 PrimaryGeneratorAction::PrimaryGeneratorAction()
0044   : G4VUserPrimaryGeneratorAction(), fParticleGun(nullptr)
0045 {
0046   G4int n_particle = 1;
0047   fParticleGun = new G4ParticleGun(n_particle);
0048
0049   // create a messenger for this class
0050   fGunMessenger = new PrimaryGeneratorMessenger(this);
0051
0052   G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
0053   G4ParticleDefinition* particle = particleTable->FindParticle("e+");
0054
0055   fParticleGun->SetParticleDefinition(particle);
0056   fParticleGun->SetParticleTime(0.0 * ns);
0057   fParticleGun->SetParticlePosition(G4ThreeVector(0.0 * cm, 0.0 * cm, 0.0 * cm));
0058   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1., 0., 0.));
0059   fParticleGun->SetParticleEnergy(500.0 * keV);
0060 }
0061
0062 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0063
0064 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0065 {
0066   delete fParticleGun;
0067   delete fGunMessenger;
0068 }
0069
0070 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0071
0072 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0073 {
0074   if (fRandomDirection) {
0075     G4double theta = CLHEP::halfpi * G4UniformRand();
0076     G4double phi = CLHEP::twopi * G4UniformRand();
0077     G4double x = std::cos(theta);
0078     G4double y = std::sin(theta) * std::sin(phi);
0079     G4double z = std::sin(theta) * std::cos(phi);
0080     G4ThreeVector dir(x, y, z);
0081     fParticleGun->SetParticleMomentumDirection(dir);
0082   }
0083   if (fParticleGun->GetParticleDefinition() == G4OpticalPhoton::OpticalPhotonDefinition()) {
0084     if (fPolarized)
0085       SetOptPhotonPolar(fPolarization);
0086     else
0087       SetOptPhotonPolar();
0088   }
0089   fParticleGun->GeneratePrimaryVertex(anEvent);
0090 }
0091
0092 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0093
0094 void PrimaryGeneratorAction::SetOptPhotonPolar()
0095 {
0096   G4double angle = G4UniformRand() * 360.0 * deg;
0097   SetOptPhotonPolar(angle);
0098 }
0099
0100 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0101
0102 void PrimaryGeneratorAction::SetOptPhotonPolar(G4double angle)
0103 {
0104   if (fParticleGun->GetParticleDefinition() != G4OpticalPhoton::OpticalPhotonDefinition()) {
0105     G4ExceptionDescription ed;
0106     ed << "The particleGun is not an opticalphoton.";
0107     G4Exception("PrimaryGeneratorAction::SetOptPhotonPolar", "OpNovice2_004", JustWarning, ed);
0108     return;
0109   }
0110
0111   fPolarized = true;
0112   fPolarization = angle;
0113
0114   G4ThreeVector normal(1., 0., 0.);
0115   G4ThreeVector kphoton = fParticleGun->GetParticleMomentumDirection();
0116   G4ThreeVector product = normal.cross(kphoton);
0117   G4double modul2 = product * product;
0118
0119   G4ThreeVector e_perpend(0., 0., 1.);
0120   if (modul2 > 0.) e_perpend = (1. / std::sqrt(modul2)) * product;
0121   G4ThreeVector e_paralle = e_perpend.cross(kphoton);
0122
0123   G4ThreeVector polar = std::cos(angle) * e_paralle + std::sin(angle) * e_perpend;
0124   fParticleGun->SetParticlePolarization(polar);
0125 }
0126
0127 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0128 void PrimaryGeneratorAction::SetRandomDirection(G4bool val)
0129 {
0130   fRandomDirection = val;
0131 }