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25 //
26 // (adapted from B1PrimaryGeneratorAction)
27 // Author: A.Knaian (ara@nklabs.com), N.MacFadden (natemacfadden@gmail.com)
28
29 #include "FAPrimaryGeneratorAction.hh"
30 #include "G4LogicalVolumeStore.hh"
31 #include "G4LogicalVolume.hh"
32 #include "G4Box.hh"
33 #include "G4RunManager.hh"
34 #include "G4ParticleGun.hh"
35 #include "G4ParticleTable.hh"
36 #include "G4ParticleDefinition.hh"
37 #include "G4SystemOfUnits.hh"
38 #include "Randomize.hh"
39
40 PrimaryGeneratorAction::PrimaryGeneratorAction()
41 : G4VUserPrimaryGeneratorAction(), fParticleGun(nullptr), fWorldBox(nullptr)
42 {
43 G4int n_particle = 1;
44 fParticleGun = new G4ParticleGun(n_particle);
45
46 // default particle kinematic
47 G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
48 G4String particleName;
49 G4ParticleDefinition* particle
50 = particleTable->FindParticle(particleName="proton");
51 fParticleGun->SetParticleDefinition(particle);
52 fParticleGun->SetParticleMomentumDirection(G4ThreeVector(0.,0.,1.));
53 fParticleGun->SetParticleEnergy(50.*MeV);
54 }
55
56 PrimaryGeneratorAction::~PrimaryGeneratorAction()
57 {
58 delete fParticleGun;
59 }
60
61 void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
62 {
63 G4double worldSizeXY = 0;
64 G4double worldSizeZ = 0;
65
66 if (!fWorldBox)
67 {
68 G4LogicalVolume* worldLV
69 = G4LogicalVolumeStore::GetInstance()->GetVolume("World");
70 if ( worldLV ) fWorldBox = dynamic_cast<G4Box*>(worldLV->GetSolid());
71 }
72 if ( fWorldBox )
73 {
74 worldSizeXY = fWorldBox->GetXHalfLength()*2.;
75 worldSizeZ = fWorldBox->GetZHalfLength()*2.;
76 }
77 else
78 {
79 G4ExceptionDescription msg;
80 msg << "World volume of box shape not found.\n";
81 msg << "Perhaps you have changed geometry.\n";
82 msg << "The gun will be place at the center.";
83 G4Exception("PrimaryGeneratorAction::GeneratePrimaries()",
84 "MyCode0002",JustWarning,msg);
85 }
86
87 // shoot on XY disk centered on Z-axis behind the cloud
88 G4double sigma = worldSizeXY/10.0; // spread in x and y
89 G4double x0 = G4RandGauss::shoot(0,sigma);
90 G4double y0 = G4RandGauss::shoot(0,sigma);
91 G4double z0 = 0.95 * (-0.5) * worldSizeZ;
92
93 fParticleGun->SetParticlePosition(G4ThreeVector(x0,y0,z0));
94 fParticleGun->GeneratePrimaryVertex(anEvent);
95 }
96
97