particleGun/src/PrimaryGeneratorAction1.cc

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0025 //
0026 /// \file PrimaryGeneratorAction1.cc
0027 /// \brief Implementation of the PrimaryGeneratorAction1 class
0028
0029 #include "PrimaryGeneratorAction1.hh"
0030
0031 #include "PrimaryGeneratorAction.hh"
0032
0033 #include "G4Event.hh"
0034 #include "G4ParticleDefinition.hh"
0035 #include "G4ParticleGun.hh"
0036 #include "G4ParticleTable.hh"
0037 #include "G4PhysicalConstants.hh"
0038 #include "G4SystemOfUnits.hh"
0039 #include "Randomize.hh"
0040
0041 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0042
0043 PrimaryGeneratorAction1::PrimaryGeneratorAction1(G4ParticleGun* gun) : fParticleGun(gun) {}
0044
0045 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0046
0047 void PrimaryGeneratorAction1::GeneratePrimaries(G4Event* anEvent)
0048 {
0049   const G4double r = 2 * mm;
0050   const G4double zmax = 8 * mm;
0051
0052   // vertex 1 uniform on cylinder
0053   //
0054   G4double alpha = twopi * G4UniformRand();  // alpha uniform in (0, 2*pi)
0055   G4double ux = std::cos(alpha);
0056   G4double uy = std::sin(alpha);
0057   G4double z = zmax * (2 * G4UniformRand() - 1);  // z uniform in (-zmax, +zmax)
0058
0059   fParticleGun->SetParticlePosition(G4ThreeVector(r * ux, r * uy, z));
0060   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(ux, uy, 0));
0061   fParticleGun->SetParticleEnergy(1 * MeV);
0062   fParticleGun->GeneratePrimaryVertex(anEvent);
0063
0064   // vertex 2 at opposite
0065   //
0066   alpha += pi;
0067   ux = std::cos(alpha);
0068   uy = std::sin(alpha);
0069   fParticleGun->SetParticlePosition(G4ThreeVector(r * ux, r * uy, z));
0070
0071   // particle 2 at vertex 2
0072   //
0073   const G4double dalpha = 10 * deg;
0074   ux = std::cos(alpha + dalpha);
0075   uy = std::sin(alpha + dalpha);
0076
0077   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(ux, uy, 0));
0078   fParticleGun->SetParticleEnergy(1 * keV);
0079   fParticleGun->GeneratePrimaryVertex(anEvent);
0080
0081   // particle 3 at vertex 3 (same as vertex 2)
0082   //
0083   ux = std::cos(alpha - dalpha);
0084   uy = std::sin(alpha - dalpha);
0085
0086   fParticleGun->SetParticleMomentumDirection(G4ThreeVector(ux, uy, 0));
0087   fParticleGun->SetParticleEnergy(1 * GeV);
0088   fParticleGun->GeneratePrimaryVertex(anEvent);
0089
0090   // randomize time zero of anEvent
0091   //
0092   G4double tmin = 0 * s, tmax = 10 * s;
0093   G4double t0 = tmin + (tmax - tmin) * G4UniformRand();
0094   G4PrimaryVertex* aVertex = anEvent->GetPrimaryVertex();
0095   while (aVertex) {
0096     aVertex->SetT0(t0);
0097     aVertex = aVertex->GetNext();
0098   }
0099 }
0100
0101 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......