generator.cc

#include "generator.hh"

MyPrimaryGenerator::MyPrimaryGenerator()
{
    fParticleGun = new G4ParticleGun(1); //1: one particle in a event
}

MyPrimaryGenerator::~MyPrimaryGenerator()
{
    delete fParticleGun;
}

void MyPrimaryGenerator::GeneratePrimaries(G4Event *anEvent)
{
    G4ParticleTable *particleTable = G4ParticleTable::GetParticleTable();
    G4String particleName = "proton"; //name of particle
    G4ParticleDefinition *particle = particleTable->FindParticle("proton");

    G4ThreeVector pos(0.,0.,0.); //create particle at center of mother volume
    G4ThreeVector mom(0.,0.,1.); //create particle in z direction

    fParticleGun->SetParticlePosition(pos);
    fParticleGun->SetParticleMomentumDirection(mom);
    fParticleGun->SetParticleMomentum(100.*GeV);
    fParticleGun->SetParticleDefinition(particle);

    fParticleGun->GeneratePrimaryVertex(anEvent);

}