| Geant4 Cross Reference |
1 //
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25 //
26 // Code developed by
27 // Silvia Pozzi (1), silvia.pozzi@iss.it
28 // Barbara Caccia (1), barbara.caccia@iss.it
29 // Carlo Mancini Terracciano (2), carlo.mancini.terracciano@roma1.infn.it
30 // (1) Istituto Superiore di Sanita' and INFN Roma, Italy
31 // (2) Univ. La Sapienza and INFN Roma, Italy
32
33 #include "DetectorConstruction.hh"
34 #include "PrimaryGeneratorAction.hh"
35 #include "PrimaryGeneratorMessenger.hh"
36
37 #include <G4ParticleTable.hh>
38 #include <G4Event.hh>
39 #include <G4SystemOfUnits.hh>
40 #include <G4ParticleGun.hh>
41 #include <G4GeneralParticleSource.hh>
42 #include <Randomize.hh>
43 #include <G4RunManager.hh>
44 #include <G4PhysicalConstants.hh>
45
46 using namespace std;
47
48 PrimaryGeneratorAction::PrimaryGeneratorAction()
49 : fGun(nullptr),
50 gunRadius(0), gunMeanEnergy(0), gunStdEnergy(0),
51 energy(0),
52 particle(nullptr)
53 {
54 priGenMessenger = new PrimaryGeneratorMessenger(this);
55 G4int n_particle = 1;
56 fGun = new G4ParticleGun(n_particle);
57 }
58
59 PrimaryGeneratorAction::~PrimaryGeneratorAction()
60 {
61 delete priGenMessenger;
62 delete fGun;
63 }
64
65 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
66 {
67 GenerateFromRandom();
68
69 fGun -> SetParticlePosition(position);
70 fGun -> SetParticleMomentumDirection((G4ParticleMomentum)direction);
71 fGun -> SetParticleEnergy(energy * MeV);
72 fGun -> SetParticleDefinition(particle);
73 // create vertex with previous specifications
74 fGun -> GeneratePrimaryVertex(anEvent);
75 }
76
77 void PrimaryGeneratorAction::GenerateFromRandom()
78 {
79 DetectorConstruction* detector = (DetectorConstruction*)
80 G4RunManager::GetRunManager() -> GetUserDetectorConstruction();
81
82 G4double zPos = -(detector -> GetAccOriginPosition()) - 5.*mm; // 5mm before the target disk
83 G4double alpha, rho, phi, sinTheta, cosTheta;
84
85 sinTheta = G4RandGauss::shoot(0., 0.003);
86 cosTheta = sqrt(1-sinTheta*sinTheta);
87 phi = twopi * G4UniformRand();
88 rho = gunRadius * G4UniformRand();
89 alpha = twopi * G4UniformRand();
90
91 particle = G4ParticleTable::GetParticleTable()->FindParticle("e-");
92 direction = {sinTheta * cos(phi), sinTheta * sin(phi), cosTheta};
93 position = {rho * sin(alpha), rho * cos(alpha), zPos};
94 energy = G4RandGauss::shoot(gunMeanEnergy, gunStdEnergy);
95 }
96
97 void PrimaryGeneratorAction::SetGunRadius(G4double value)
98 {
99 gunRadius = value;
100 }
101
102 void PrimaryGeneratorAction::SetGunMeanEnergy(G4double value)
103 {
104 gunMeanEnergy = value;
105 }
106
107 void PrimaryGeneratorAction::SetGunStdEnergy(G4double value)
108 {
109 gunStdEnergy = value;
110 }
111