TestEm6/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* DC)
0044   : G4VUserPrimaryGeneratorAction(), fParticleGun(0), fDetector(DC), fRndmBeam(0), fGunMessenger(0)
0045 {
0046   fParticleGun = new G4ParticleGun(1);
0047   G4ParticleDefinition* particle = G4ParticleTable::GetParticleTable()->FindParticle("gamma");
0048   fParticleGun->SetParticleDefinition(particle);
0049   fParticleGun->SetParticleEnergy(100 * TeV);
0050   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1., 0., 0.));
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::GeneratePrimaries(G4Event* anEvent)
0067 {
0068   // this function is called at the begining of event
0069   //
0070   G4double x0 = -0.5 * (fDetector->GetSize());
0071   G4double y0 = 0. * cm, z0 = 0. * cm;
0072
0073   // randomize the beam, if requested.
0074   //
0075   if (fRndmBeam > 0.) {
0076     G4double rbeam = 0.5 * (fDetector->GetSize()) * fRndmBeam;
0077     y0 = (2 * G4UniformRand() - 1.) * rbeam;
0078     z0 = (2 * G4UniformRand() - 1.) * rbeam;
0079   }
0080   fParticleGun->SetParticlePosition(G4ThreeVector(x0, y0, z0));
0081   fParticleGun->GeneratePrimaryVertex(anEvent);
0082 }
0083
0084 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......