shared/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 "G4Box.hh"
0032 #include "G4Event.hh"
0033 #include "G4LogicalVolume.hh"
0034 #include "G4LogicalVolumeStore.hh"
0035 #include "G4ParticleGun.hh"
0036 #include "G4ParticleTable.hh"
0037 #include "G4Proton.hh"
0038 #include "G4RunManager.hh"
0039 #include "G4SystemOfUnits.hh"
0040 #include "Randomize.hh"
0041
0042 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0043
0044 PrimaryGeneratorAction::PrimaryGeneratorAction()
0045 {
0046   G4int nofParticles = 1;
0047   fParticleGun = new G4ParticleGun(nofParticles);
0048
0049   // default particle kinematic
0050   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
0051   fParticleGun->SetParticleEnergy(1. * GeV);
0052   fParticleGun->SetParticleDefinition(G4Proton::Proton());
0053 }
0054
0055 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0056
0057 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0058 {
0059   delete fParticleGun;
0060 }
0061
0062 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0063
0064 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0065 {
0066   // This function is called at the begining of event
0067
0068   // In order to avoid dependence of PrimaryGeneratorAction
0069   // on DetectorConstruction class we get world volume
0070   // from G4LogicalVolumeStore
0071   //
0072   G4double worldZHalfLength = 0.;
0073   auto worldLV = G4LogicalVolumeStore::GetInstance()->GetVolume("World");
0074
0075   // Check that the world volume has box shape
0076   G4Box* worldBox = nullptr;
0077   if (worldLV) {
0078     worldBox = dynamic_cast<G4Box*>(worldLV->GetSolid());
0079   }
0080
0081   if (worldBox) {
0082     worldZHalfLength = worldBox->GetZHalfLength();
0083   }
0084   else {
0085     G4ExceptionDescription msg;
0086     msg << "World volume of box shape not found." << G4endl;
0087     msg << "Perhaps you have changed geometry." << G4endl;
0088     msg << "The gun will be place in the center.";
0089     G4Exception("PrimaryGeneratorAction::GeneratePrimaries()", "MyCode0002", JustWarning, msg);
0090   }
0091
0092   // Set gun position
0093   fParticleGun->SetParticlePosition(G4ThreeVector(0., 0., -worldZHalfLength));
0094
0095   fParticleGun->GeneratePrimaryVertex(anEvent);
0096 }
0097
0098 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......