TestEm12/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 "PrimaryGeneratorMessenger.hh"
0032
0033 #include "G4Event.hh"
0034 #include "G4ParticleDefinition.hh"
0035 #include "G4ParticleGun.hh"
0036 #include "G4ParticleTable.hh"
0037 #include "G4PhysicalConstants.hh"
0038 #include "G4SystemOfUnits.hh"
0039 #include "Randomize.hh"
0040
0041 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0042
0043 PrimaryGeneratorAction::PrimaryGeneratorAction()
0044 {
0045   fParticleGun = new G4ParticleGun(1);
0046   G4ParticleDefinition* particle = G4ParticleTable::GetParticleTable()->FindParticle("e-");
0047   fParticleGun->SetParticleDefinition(particle);
0048   fParticleGun->SetParticleEnergy(4 * MeV);
0049   fParticleGun->SetParticlePosition(G4ThreeVector());
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   // randomize the beam, if requested.
0069   //
0070   if (fRndmBeam) {
0071     // distribution uniform in solid angle
0072     //
0073     G4double cosTheta = 2 * G4UniformRand() - 1., phi = twopi * G4UniformRand();
0074     G4double sinTheta = std::sqrt(1. - cosTheta * cosTheta);
0075     G4double ux = sinTheta * std::cos(phi), uy = sinTheta * std::sin(phi), uz = cosTheta;
0076     fParticleGun->SetParticleMomentumDirection(G4ThreeVector(ux, uy, uz));
0077   }
0078
0079   fParticleGun->GeneratePrimaryVertex(anEvent);
0080 }
0081
0082 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......