Activation/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 "DetectorConstruction.hh"
0032 #include "PrimaryGeneratorMessenger.hh"
0033
0034 #include "G4Event.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(DetectorConstruction* det) : fDetector(det)
0044 {
0045   fParticleGun = new G4ParticleGun(1);
0046   SetDefaultKinematic();
0047
0048   // create a messenger for this class
0049   fGunMessenger = new PrimaryGeneratorMessenger(this);
0050 }
0051
0052 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0053
0054 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0055 {
0056   delete fParticleGun;
0057   delete fGunMessenger;
0058 }
0059
0060 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0061
0062 void PrimaryGeneratorAction::SetDefaultKinematic()
0063 {
0064   G4ParticleDefinition* particle = G4ParticleTable::GetParticleTable()->FindParticle("proton");
0065   fParticleGun->SetParticleDefinition(particle);
0066   fParticleGun->SetParticleEnergy(10 * MeV);
0067   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1., 0., 0.));
0068   G4double position = -0.45 * (fDetector->GetWorldSizeX());
0069   fParticleGun->SetParticlePosition(G4ThreeVector(position, 0. * cm, 0. * cm));
0070 }
0071 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0072
0073 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0074 {
0075   // this function is called at the begining of event
0076
0077   // randomize the beam, if requested.
0078   //
0079   if (fRndmBeam > 0.) {
0080     G4ThreeVector oldPosition = fParticleGun->GetParticlePosition();
0081     if (fRndmBeam > fDetector->GetAbsorSizeYZ()) fRndmBeam = fDetector->GetAbsorSizeYZ();
0082     G4double rbeam = 0.5 * fRndmBeam;
0083     G4double x0 = oldPosition.x();
0084     G4double y0 = oldPosition.y() + (2 * G4UniformRand() - 1.) * rbeam;
0085     G4double z0 = oldPosition.z() + (2 * G4UniformRand() - 1.) * rbeam;
0086     fParticleGun->SetParticlePosition(G4ThreeVector(x0, y0, z0));
0087     fParticleGun->GeneratePrimaryVertex(anEvent);
0088     fParticleGun->SetParticlePosition(oldPosition);
0089   }
0090
0091   else
0092     fParticleGun->GeneratePrimaryVertex(anEvent);
0093
0094   // randomize time zero of anEvent
0095   //
0096   G4double t0 = fTimeExposure * G4UniformRand();
0097   anEvent->GetPrimaryVertex()->SetT0(t0);
0098 }
0099
0100 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......