|Message: Re: Particle Source Biasing||Not Logged In (login)|
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You can choose the angle randomly. If it is not within the interesting angle, discard the particle with probability p.
If you don't want to bias the result, then multiply the weights of surviving particles (not in the interesting solid angle) by 1/(1-p).
To "shoot" the particle: In your
calculate particle properties, create a vertex, assign properties, and add it to the event. Here's some of it (reply if you need more):
G4ParticleTable* particle_table = G4ParticleTable::GetParticleTable(); G4ParticleDefinition* particle_def = particle_table->FindParticle(type); G4double particle_time = 0.0;
G4PrimaryVertex* vertex = new G4PrimaryVertex(particle_position,particle_time);
G4PrimaryParticle* particle = new G4PrimaryParticle(particle_def,u,v,w); particle->SetWeight(weight); vertex->SetPrimary(particle); anEvent->AddPrimaryVertex(vertex);
(Better would be to use G4ParticleGun, but I'm not aware of a way to set the weight using G4ParticleGun.)