| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 /// \file B2/B2a/src/PrimaryGeneratorAction.cc
28 /// \brief Implementation of the B2::PrimaryGeneratorAction class
29
30 #include "PrimaryGeneratorAction.hh"
31
32 #include "G4Box.hh"
33 #include "G4LogicalVolume.hh"
34 #include "G4LogicalVolumeStore.hh"
35 #include "G4ParticleGun.hh"
36 #include "G4ParticleTable.hh"
37 #include "G4SystemOfUnits.hh"
38
39 namespace B2
40 {
41
42 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
43
44 PrimaryGeneratorAction::PrimaryGeneratorAction()
45 {
46 G4int nofParticles = 1;
47 fParticleGun = new G4ParticleGun(nofParticles);
48
49 // default particle kinematic
50
51 G4ParticleDefinition* particleDefinition =
52 G4ParticleTable::GetParticleTable()->FindParticle("proton");
53
54 fParticleGun->SetParticleDefinition(particleDefinition);
55 fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
56 fParticleGun->SetParticleEnergy(3.0 * GeV);
57 }
58
59 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
60
61 PrimaryGeneratorAction::~PrimaryGeneratorAction()
62 {
63 delete fParticleGun;
64 }
65
66 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
67
68 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* event)
69 {
70 // This function is called at the begining of event
71
72 // In order to avoid dependence of PrimaryGeneratorAction
73 // on DetectorConstruction class we get world volume
74 // from G4LogicalVolumeStore.
75
76 G4double worldZHalfLength = 0;
77 G4LogicalVolume* worldLV = G4LogicalVolumeStore::GetInstance()->GetVolume("World");
78 G4Box* worldBox = nullptr;
79 if (worldLV) worldBox = dynamic_cast<G4Box*>(worldLV->GetSolid());
80 if (worldBox)
81 worldZHalfLength = worldBox->GetZHalfLength();
82 else {
83 G4cerr << "World volume of box not found." << G4endl;
84 G4cerr << "Perhaps you have changed geometry." << G4endl;
85 G4cerr << "The gun will be place in the center." << G4endl;
86 }
87
88 // Starting a primary particle close to the world boundary.
89 //
90 fParticleGun->SetParticlePosition(G4ThreeVector(0., 0., -worldZHalfLength + 1 * um));
91
92 fParticleGun->GeneratePrimaryVertex(event);
93 }
94
95 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
96
97 } // namespace B2
98