OpNovice2/src/PrimaryGeneratorAction.cc

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0026 /// \file optical/OpNovice2/src/PrimaryGeneratorAction.cc
0027 /// \brief Implementation of the PrimaryGeneratorAction class
0028 //
0029 //
0030 //
0031 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0032 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0033
0034 #include "PrimaryGeneratorAction.hh"
0035
0036 #include "PrimaryGeneratorMessenger.hh"
0037
0038 #include "G4Event.hh"
0039 #include "G4OpticalPhoton.hh"
0040 #include "G4ParticleDefinition.hh"
0041 #include "G4ParticleGun.hh"
0042 #include "G4ParticleTable.hh"
0043 #include "G4SystemOfUnits.hh"
0044 #include "Randomize.hh"
0045
0046 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0047
0048 PrimaryGeneratorAction::PrimaryGeneratorAction()
0049   : G4VUserPrimaryGeneratorAction(), fParticleGun(nullptr)
0050 {
0051   G4int n_particle = 1;
0052   fParticleGun = new G4ParticleGun(n_particle);
0053
0054   // create a messenger for this class
0055   fGunMessenger = new PrimaryGeneratorMessenger(this);
0056
0057   G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
0058   G4ParticleDefinition* particle = particleTable->FindParticle("e+");
0059
0060   fParticleGun->SetParticleDefinition(particle);
0061   fParticleGun->SetParticleTime(0.0 * ns);
0062   fParticleGun->SetParticlePosition(G4ThreeVector(0.0 * cm, 0.0 * cm, 0.0 * cm));
0063   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1., 0., 0.));
0064   fParticleGun->SetParticleEnergy(500.0 * keV);
0065 }
0066
0067 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0068
0069 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0070 {
0071   delete fParticleGun;
0072   delete fGunMessenger;
0073 }
0074
0075 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0076
0077 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0078 {
0079   if (fRandomDirection) {
0080     G4double theta = CLHEP::halfpi * G4UniformRand();
0081     G4double phi = CLHEP::twopi * G4UniformRand();
0082     G4double x = std::cos(theta);
0083     G4double y = std::sin(theta) * std::sin(phi);
0084     G4double z = std::sin(theta) * std::cos(phi);
0085     G4ThreeVector dir(x, y, z);
0086     fParticleGun->SetParticleMomentumDirection(dir);
0087   }
0088   if (fParticleGun->GetParticleDefinition() == G4OpticalPhoton::OpticalPhotonDefinition()) {
0089     if (fPolarized)
0090       SetOptPhotonPolar(fPolarization);
0091     else
0092       SetOptPhotonPolar();
0093   }
0094   fParticleGun->GeneratePrimaryVertex(anEvent);
0095 }
0096
0097 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0098
0099 void PrimaryGeneratorAction::SetOptPhotonPolar()
0100 {
0101   G4double angle = G4UniformRand() * 360.0 * deg;
0102   SetOptPhotonPolar(angle);
0103 }
0104
0105 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0106
0107 void PrimaryGeneratorAction::SetOptPhotonPolar(G4double angle)
0108 {
0109   if (fParticleGun->GetParticleDefinition() != G4OpticalPhoton::OpticalPhotonDefinition()) {
0110     G4ExceptionDescription ed;
0111     ed << "The particleGun is not an opticalphoton.";
0112     G4Exception("PrimaryGeneratorAction::SetOptPhotonPolar", "OpNovice2_004", JustWarning, ed);
0113     return;
0114   }
0115
0116   fPolarized = true;
0117   fPolarization = angle;
0118
0119   G4ThreeVector normal(1., 0., 0.);
0120   G4ThreeVector kphoton = fParticleGun->GetParticleMomentumDirection();
0121   G4ThreeVector product = normal.cross(kphoton);
0122   G4double modul2 = product * product;
0123
0124   G4ThreeVector e_perpend(0., 0., 1.);
0125   if (modul2 > 0.) e_perpend = (1. / std::sqrt(modul2)) * product;
0126   G4ThreeVector e_paralle = e_perpend.cross(kphoton);
0127
0128   G4ThreeVector polar = std::cos(angle) * e_paralle + std::sin(angle) * e_perpend;
0129   fParticleGun->SetParticlePolarization(polar);
0130 }
0131
0132 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0133 void PrimaryGeneratorAction::SetRandomDirection(G4bool val)
0134 {
0135   fRandomDirection = val;
0136 }