Activation/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 #include "PrimaryGeneratorMessenger.hh"
0037
0038 #include "G4Event.hh"
0039 #include "G4ParticleDefinition.hh"
0040 #include "G4ParticleGun.hh"
0041 #include "G4ParticleTable.hh"
0042 #include "G4SystemOfUnits.hh"
0043 #include "Randomize.hh"
0044
0045 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0046
0047 PrimaryGeneratorAction::PrimaryGeneratorAction(DetectorConstruction* det) : fDetector(det)
0048 {
0049   fParticleGun = new G4ParticleGun(1);
0050   SetDefaultKinematic();
0051
0052   // create a messenger for this class
0053   fGunMessenger = new PrimaryGeneratorMessenger(this);
0054 }
0055
0056 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0057
0058 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0059 {
0060   delete fParticleGun;
0061   delete fGunMessenger;
0062 }
0063
0064 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0065
0066 void PrimaryGeneratorAction::SetDefaultKinematic()
0067 {
0068   G4ParticleDefinition* particle = G4ParticleTable::GetParticleTable()->FindParticle("proton");
0069   fParticleGun->SetParticleDefinition(particle);
0070   fParticleGun->SetParticleEnergy(10 * MeV);
0071   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1., 0., 0.));
0072   G4double position = -0.45 * (fDetector->GetWorldSizeX());
0073   fParticleGun->SetParticlePosition(G4ThreeVector(position, 0. * cm, 0. * cm));
0074 }
0075 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0076
0077 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0078 {
0079   // this function is called at the begining of event
0080
0081   // randomize the beam, if requested.
0082   //
0083   if (fRndmBeam > 0.) {
0084     G4ThreeVector oldPosition = fParticleGun->GetParticlePosition();
0085     if (fRndmBeam > fDetector->GetAbsorSizeYZ()) fRndmBeam = fDetector->GetAbsorSizeYZ();
0086     G4double rbeam = 0.5 * fRndmBeam;
0087     G4double x0 = oldPosition.x();
0088     G4double y0 = oldPosition.y() + (2 * G4UniformRand() - 1.) * rbeam;
0089     G4double z0 = oldPosition.z() + (2 * G4UniformRand() - 1.) * rbeam;
0090     fParticleGun->SetParticlePosition(G4ThreeVector(x0, y0, z0));
0091     fParticleGun->GeneratePrimaryVertex(anEvent);
0092     fParticleGun->SetParticlePosition(oldPosition);
0093   }
0094
0095   else
0096     fParticleGun->GeneratePrimaryVertex(anEvent);
0097
0098   // randomize time zero of anEvent
0099   //
0100   G4double t0 = fTimeExposure * G4UniformRand();
0101   anEvent->GetPrimaryVertex()->SetT0(t0);
0102 }
0103
0104 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......