TestEm1/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 "G4ParticleTable.hh"
0037 #include "G4SystemOfUnits.hh"
0038 #include "Randomize.hh"
0039
0040 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0041
0042 PrimaryGeneratorAction::PrimaryGeneratorAction(DetectorConstruction* det) : fDetector(det)
0043 {
0044   fParticleGun = new G4ParticleGun(1);
0045   SetDefaultKinematic(1);
0046
0047   // create a messenger for this class
0048   fGunMessenger = new PrimaryGeneratorMessenger(this);
0049 }
0050
0051 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0052
0053 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0054 {
0055   delete fParticleGun;
0056   delete fGunMessenger;
0057 }
0058
0059 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0060
0061 void PrimaryGeneratorAction::SetDefaultKinematic(G4int front)
0062 {
0063   G4ParticleDefinition* particle = G4ParticleTable::GetParticleTable()->FindParticle("e-");
0064   fParticleGun->SetParticleDefinition(particle);
0065   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1., 0., 0.));
0066   fParticleGun->SetParticleEnergy(100 * MeV);
0067   G4double position = 0. * cm;
0068   if (front) position = -0.4999 * (fDetector->GetSize());
0069   fParticleGun->SetParticlePosition(G4ThreeVector(position, 0. * cm, 0. * cm));
0070 }
0071
0072 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0073
0074 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0075 {
0076   // this function is called at the begining of event
0077   //
0078   // randomize the beam, if requested.
0079   if (fRndmBeam > 0.) {
0080     G4ThreeVector oldPosition = fParticleGun->GetParticlePosition();
0081     G4double rbeam = 0.5 * (fDetector->GetSize()) * fRndmBeam;
0082     G4double x0 = oldPosition.x();
0083     G4double y0 = oldPosition.y() + (2 * G4UniformRand() - 1.) * rbeam;
0084     G4double z0 = oldPosition.z() + (2 * G4UniformRand() - 1.) * rbeam;
0085     fParticleGun->SetParticlePosition(G4ThreeVector(x0, y0, z0));
0086     fParticleGun->GeneratePrimaryVertex(anEvent);
0087     fParticleGun->SetParticlePosition(oldPosition);
0088   }
0089   else
0090     fParticleGun->GeneratePrimaryVertex(anEvent);
0091 }
0092
0093 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......