BlineTracer/src/G4BlinePrimaryGeneratorAction.cc

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0026 /// \file field/BlineTracer/src/G4BlinePrimaryGeneratorAction.cc
0027 /// \brief Implementation of the G4BlinePrimaryGeneratorAction class
0028 //
0029 //
0030 //
0031 //
0032 // --------------------------------------------------------------------
0033 //
0034 // G4BlinePrimaryGeneratorAction implementation
0035 //
0036 // --------------------------------------------------------------------
0037 // Author: Laurent Desorgher (desorgher@phim.unibe.ch)
0038 //         Created - 2003-10-06
0039 // --------------------------------------------------------------------
0040
0041 #include "G4BlinePrimaryGeneratorAction.hh"
0042
0043 #include "G4ChargedGeantino.hh"
0044 #include "G4Event.hh"
0045 #include "G4SystemOfUnits.hh"
0046 #include "G4Types.hh"
0047
0048 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0049
0050 void G4BlinePrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
0051 {
0052   if (!fUserPrimaryAction) {
0053     G4Exception("G4BlinePrimaryGeneratorAction::GeneratePrimaries()", "NullPointer", JustWarning,
0054                 "Primary generator action not defined !");
0055     return;
0056   }
0057
0058   // For the first part of a bline the start position and time are defined
0059   // by using the USER primary action while for the second part the previous
0060   // values are taken.
0061
0062   if (fFirstPartOfBline) {
0063     // set the position and time defined by using the USER primary action
0064
0065     auto tmpEvent = new G4Event();
0066     fUserPrimaryAction->GeneratePrimaries(tmpEvent);
0067     fBlineStartPosition = tmpEvent->GetPrimaryVertex()->GetPosition();
0068     fT0 = tmpEvent->GetPrimaryVertex()->GetT0();
0069     delete tmpEvent;
0070   }
0071   fFirstPartOfBline = false;
0072
0073   auto primary_vertex = new G4PrimaryVertex(fBlineStartPosition, fT0);
0074
0075   // Define the particle to be tracked as Charged Geantino
0076
0077   G4ChargedGeantino* pdef = G4ChargedGeantino::ChargedGeantino();
0078
0079   G4double mass = pdef->GetPDGMass();
0080   G4double energy = 10000. * MeV + mass;
0081   G4double pmom = std::sqrt(energy * energy - mass * mass);
0082
0083   // The momentum direction and energy do not have an effect in tracing of
0084   // bline but still need to be defined.
0085
0086   G4double px = 0.;
0087   G4double py = 0.;
0088   G4double pz = pmom;
0089
0090   auto particle = new G4PrimaryParticle(pdef, px, py, pz);
0091   particle->SetMass(mass);
0092   particle->SetCharge(pdef->GetPDGCharge());
0093   primary_vertex->SetPrimary(particle);
0094
0095   anEvent->AddPrimaryVertex(primary_vertex);
0096 }