MultiParticleGunPrimaryGenerator.cxx

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#include "SimCore/Generators/MultiParticleGunPrimaryGenerator.h"
 
namespace simcore {
namespace generators {
 
MultiParticleGunPrimaryGenerator::MultiParticleGunPrimaryGenerator(
    const std::string& name, const framework::config::Parameters& parameters)
    : PrimaryGenerator(name, parameters), random_(new TRandom) {
  auto stlVertex{parameters.getParameter<std::vector<double> >("vertex")};
  auto stlMomentum{parameters.getParameter<std::vector<double> >("momentum")};
  mpgNParticles_ = parameters.getParameter<int>("nParticles");
  mpgPdgID_ = parameters.getParameter<int>("pdgID");
  mpgEnablePoisson_ = parameters.getParameter<bool>("enablePoisson");
 
  if (stlVertex.size() != 3 or stlMomentum.size() != 3 or mpgNParticles_ <= 0) {
    EXCEPTION_RAISE("InvalideConfig",
                    "Parameters pass to '" + name_ + "' are not valid.");
  }
 
  mpgVertex_ = G4ThreeVector(stlVertex.at(0) * mm, stlVertex.at(1) * mm,
                             stlVertex.at(2) * mm);
  mpgMomentum_ = G4ThreeVector(stlMomentum.at(0) * MeV, stlMomentum.at(1) * MeV,
                               stlMomentum.at(2) * MeV);
}
 
MultiParticleGunPrimaryGenerator::~MultiParticleGunPrimaryGenerator() {
  delete random_;
}
 
void MultiParticleGunPrimaryGenerator::GeneratePrimaryVertex(G4Event* anEvent) {
  int cur_mpg_pdgid = mpgPdgID_;
  G4ThreeVector cur_mpg_vertex = mpgVertex_;
  G4ThreeVector cur_mpg_momentum = mpgMomentum_;
 
  // current number of vertices in the event!
  int curNVertices = anEvent->GetNumberOfPrimaryVertex();
 
  double nInteractionsInput = mpgNParticles_;
  int nInteractions = nInteractionsInput;
  if (mpgEnablePoisson_) {
    nInteractions = 0;
    while (nInteractions == 0) {  // keep generating a random poisson until > 0,
                                  // no point in generator 0 vertices...
      nInteractions = random_->Poisson(nInteractionsInput);
    }
  }
 
  // make a for loop
  for (int i = 0; i < (nInteractions - curNVertices); ++i) {
    G4PrimaryVertex* curvertex =
        new G4PrimaryVertex(cur_mpg_vertex, 0.);  // second input is t0
    // curvertex->SetPosition(0. * mm,0. * mm,-10. * mm);
    curvertex->SetWeight(1.);
 
    G4PrimaryParticle* primary =
        new G4PrimaryParticle(cur_mpg_pdgid, cur_mpg_momentum.x(),
                              cur_mpg_momentum.y(), cur_mpg_momentum.z());
 
    UserPrimaryParticleInformation* primaryInfo =
        new UserPrimaryParticleInformation();
    primaryInfo->setHepEvtStatus(1.);
    primary->SetUserInformation(primaryInfo);
 
    curvertex->SetPrimary(primary);
    anEvent->AddPrimaryVertex(curvertex);
  }
}
 
void MultiParticleGunPrimaryGenerator::RecordConfig(const std::string& id,
                                                    ldmx::RunHeader& rh) {
  rh.setStringParameter(
      id + " Class", "simcore::generators::MultiParticleGunPrimaryGenerator");
  rh.setIntParameter(id + " Poisson Enabled", mpgEnablePoisson_);
  rh.setFloatParameter(id + " N Particles", mpgNParticles_);
  rh.setIntParameter(id + " PDG ID", mpgPdgID_);
  rh.setFloatParameter(id + " Vertex X [mm]", mpgVertex_.x());
  rh.setFloatParameter(id + " Vertex Y [mm]", mpgVertex_.y());
  rh.setFloatParameter(id + " Vertex Z [mm]", mpgVertex_.z());
  rh.setFloatParameter(id + " Momentum X [MeV]", mpgMomentum_.x());
  rh.setFloatParameter(id + " Momentum Y [MeV]", mpgMomentum_.y());
  rh.setFloatParameter(id + " Momentum Z [MeV]", mpgMomentum_.z());
}
 
}  // namespace generators
}  // namespace simcore
 
DECLARE_GENERATOR(simcore::generators::MultiParticleGunPrimaryGenerator)