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// $Id: DicomPrimaryGeneratorAction.cc 74809 2013-10-22 09:49:26Z gcosmo $
//
/// \file medical/DICOM/src/DicomPrimaryGeneratorAction.cc
/// \brief Implementation of the DicomPrimaryGeneratorAction class
//
// The code was written by :
//      *Louis Archambault louis.archambault@phy.ulaval.ca,
//      *Luc Beaulieu beaulieu@phy.ulaval.ca
//      +Vincent Hubert-Tremblay at tigre.2@sympatico.ca
//
//
// *Centre Hospitalier Universitaire de Quebec (CHUQ),
// Hotel-Dieu de Quebec, departement de Radio-oncologie
// 11 cote du palais. Quebec, QC, Canada, G1R 2J6
// tel (418) 525-4444 #6720
// fax (418) 691 5268
//
// + Université Laval, Québec (QC) Canada
//*******************************************************

#include "DicomPrimaryGeneratorAction.hh"

#include "G4Event.hh"
#include "G4ParticleGun.hh"
#include "G4ParticleTable.hh"
#include "DicomRegularDetectorConstruction.hh"
#include "G4ParticleDefinition.hh"
#include "G4SystemOfUnits.hh"
#include "Randomize.hh"
#include "CLHEP/Random/RandFlat.h"

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
DicomPrimaryGeneratorAction::DicomPrimaryGeneratorAction()
 : G4VUserPrimaryGeneratorAction(),
   fParticleGun(0)
{
  G4int nParticle = 1;
  fParticleGun  = new G4ParticleGun(nParticle);               
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
DicomPrimaryGeneratorAction::~DicomPrimaryGeneratorAction()
{
  delete fParticleGun;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
void DicomPrimaryGeneratorAction::GeneratePrimaries(G4Event *anEvent)
{
  G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
  G4String particleName;
  G4ParticleDefinition* particle
    = particleTable->FindParticle(particleName="e-");
  fParticleGun->SetParticleDefinition(particle);
  // put the e- in the x direction of the patient (z in the accelerator axs) 
  // to hit patient in the central slice of the phantom
  G4ThreeVector dir(0,0,1);
  //G4ThreeVector dir(2.*CLHEP::RandFlat::shoot()-1.,
  //2.*CLHEP::RandFlat::shoot()-1.,-CLHEP::RandFlat::shoot());
  dir /= dir.mag();
  fParticleGun->SetParticleMomentumDirection(dir);       
  fParticleGun->SetParticleEnergy(100.*MeV);
  //put it at SAD = 1 m on xy plane of central slice
  fParticleGun->SetParticlePosition(G4ThreeVector(0.,0.,0.));
  //fParticleGun->SetParticlePosition(G4ThreeVector(0.,0.,-22.));
  fParticleGun->GeneratePrimaryVertex(anEvent);
}