shared/src/PrimaryGeneratorAction.cc

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0026 //
0027 /// \file PrimaryGeneratorAction.cc
0028 /// \brief Implementation of the PrimaryGeneratorAction class
0029
0030 #include "PrimaryGeneratorAction.hh"
0031
0032 #include "G4Box.hh"
0033 #include "G4Event.hh"
0034 #include "G4LogicalVolume.hh"
0035 #include "G4LogicalVolumeStore.hh"
0036 #include "G4ParticleGun.hh"
0037 #include "G4ParticleTable.hh"
0038 #include "G4Proton.hh"
0039 #include "G4RunManager.hh"
0040 #include "G4SystemOfUnits.hh"
0041 #include "Randomize.hh"
0042
0043 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0044
0045 PrimaryGeneratorAction::PrimaryGeneratorAction()
0046 {
0047   G4int nofParticles = 1;
0048   fParticleGun = new G4ParticleGun(nofParticles);
0049
0050   // default particle kinematic
0051   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
0052   fParticleGun->SetParticleEnergy(1. * GeV);
0053   fParticleGun->SetParticleDefinition(G4Proton::Proton());
0054 }
0055
0056 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0057
0058 PrimaryGeneratorAction::~PrimaryGeneratorAction()
0059 {
0060   delete fParticleGun;
0061 }
0062
0063 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0064
0065 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0066 {
0067   // This function is called at the begining of event
0068
0069   // In order to avoid dependence of PrimaryGeneratorAction
0070   // on DetectorConstruction class we get world volume
0071   // from G4LogicalVolumeStore
0072   //
0073   G4double worldZHalfLength = 0.;
0074   auto worldLV = G4LogicalVolumeStore::GetInstance()->GetVolume("World");
0075
0076   // Check that the world volume has box shape
0077   G4Box* worldBox = nullptr;
0078   if (worldLV) {
0079     worldBox = dynamic_cast<G4Box*>(worldLV->GetSolid());
0080   }
0081
0082   if (worldBox) {
0083     worldZHalfLength = worldBox->GetZHalfLength();
0084   }
0085   else {
0086     G4ExceptionDescription msg;
0087     msg << "World volume of box shape not found." << G4endl;
0088     msg << "Perhaps you have changed geometry." << G4endl;
0089     msg << "The gun will be place in the center.";
0090     G4Exception("PrimaryGeneratorAction::GeneratePrimaries()", "MyCode0002", JustWarning, msg);
0091   }
0092
0093   // Set gun position
0094   fParticleGun->SetParticlePosition(G4ThreeVector(0., 0., -worldZHalfLength));
0095
0096   fParticleGun->GeneratePrimaryVertex(anEvent);
0097 }
0098
0099 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......