| 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 // This example is provided by the Geant4-DNA collaboration
27 // Any report or published results obtained using the Geant4-DNA software
28 // shall cite the following Geant4-DNA collaboration publication:
29 // Med. Phys. 37 (2010) 4692-4708
30 // The Geant4-DNA web site is available at http://geant4-dna.org
31 //
32 // If you use this example, please cite the following publication:
33 // Rad. Prot. Dos. 133 (2009) 2-11
34 //
35 #include "PrimaryGeneratorAction.hh"
36 #include "G4SystemOfUnits.hh"
37 #include "G4Event.hh"
38 #include "G4ParticleTable.hh"
39 #include "Randomize.hh"
40
41 PrimaryGeneratorAction::PrimaryGeneratorAction()
42 {
43 fParticleGun = new G4ParticleGun(1);
44 }
45
46 PrimaryGeneratorAction::~PrimaryGeneratorAction()
47 {
48 delete fParticleGun;
49 }
50
51 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
52 {
53 G4int numEvent;
54 numEvent=anEvent->GetEventID()+1;
55 G4double x0,y0,z0,theta,phi,xMom0,yMom0,zMom0,e0;
56
57 // INITIAL BEAM POSITION
58
59 z0=-10000*mm;
60 x0=10*mm;
61 y0=10*mm;
62
63 G4double sizeMax = 0.5*micrometer; // INITIAL BEAM POSITION UNIFORMLY SPREAD ON A DISK
64 while (! (std::sqrt(x0*x0+y0*y0)<= sizeMax) )
65 {
66 x0 = CLHEP::RandFlat::shoot(-sizeMax,sizeMax);
67 y0 = CLHEP::RandFlat::shoot(-sizeMax,sizeMax);
68 }
69
70 // INITIAL BEAM ENERGY
71
72 e0= G4RandGauss::shoot(3*MeV,5.0955e-5*MeV); // AIFIRA ENERGY RESOLUTION
73
74 // INITIAL BEAM DIVERGENCE
75
76 do {
77 theta=std::acos(1-G4UniformRand()*(1.0-std::cos(1.1e-6)))*rad;
78 }
79 while(theta>1.1e-6*rad);
80
81 phi=CLHEP::twopi*G4UniformRand()*rad;
82
83 xMom0=std::sin(theta)*std::cos(phi);
84 yMom0=std::sin(theta)*std::sin(phi);
85 zMom0=std::cos(theta);
86
87 // VERBOSE
88
89 G4cout
90 << "-> Event # " << numEvent
91 << " generated "
92 << G4endl;
93
94 /*
95 G4cout
96 << "-> Event # " << numEvent
97 << " : THETA from Z axis (mrad) = " << theta*1000
98 << " -- PHI (deg) = " << phi*180/CLHEP::pi
99 << " -- x0 (um) = " << x0/micrometer
100 << " -- y0 (um) = " << y0/micrometer
101 << " -- z0 (m) = " << z0/m
102 << " -- e0 (MeV) = " << e0/MeV
103 << G4endl;
104 */
105
106 fParticleGun->SetParticleEnergy(e0);
107
108 fParticleGun->SetParticleMomentumDirection(G4ThreeVector(xMom0,yMom0,zMom0));
109
110 fParticleGun->SetParticlePosition(G4ThreeVector(x0,y0,z0));
111
112 G4ParticleDefinition* particle=
113 G4ParticleTable::GetParticleTable()->FindParticle("alpha");
114
115 fParticleGun->SetParticleDefinition(particle);
116
117 fParticleGun->GeneratePrimaryVertex(anEvent);
118
119 }
120