source: trunk/source/geometry/solids/test/OpticalEscape/src/AXPETPrimaryGeneratorAction.cc @ 1316

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// $Id: AXPETPrimaryGeneratorAction.cc,v 1.1 2008/09/03 13:34:03 gcosmo Exp $
// ------------------------------------------------------------
// Geant4 class implementation file
//
// 03/09/2008, by T.Nikitina
// ------------------------------------------------------------

#include "AXPETPrimaryGeneratorAction.hh"
#include "AXPETPrimaryGeneratorMessenger.hh"

#include "Randomize.hh"

#include "G4Event.hh"
#include "G4ParticleGun.hh"
#include "G4ParticleTable.hh"
#include "G4ParticleDefinition.hh"

AXPETPrimaryGeneratorAction::AXPETPrimaryGeneratorAction()
{

  G4int n_particle = 1;
  particleGun = new G4ParticleGun(n_particle);
  
  //create a messenger for this class
  gunMessenger = new AXPETPrimaryGeneratorMessenger(this);
  
  //default kinematic
  //
  G4ParticleTable* particleTable = G4ParticleTable::GetParticleTable();
  G4ParticleDefinition* particle = particleTable->FindParticle("e-");

  particleGun->SetParticleDefinition(particle);
  particleGun->SetParticleTime(0.0*ns);

  particleGun->SetParticlePosition(G4ThreeVector(0.0*cm,0.0*mm,15.0*cm));
  particleGun->SetParticleMomentumDirection(G4ThreeVector(0.,0.,-1.));
  particleGun->SetParticleEnergy(20.0*keV);
}

AXPETPrimaryGeneratorAction::~AXPETPrimaryGeneratorAction()
{
  delete particleGun;
  delete gunMessenger;
}

void AXPETPrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
{

  G4double sigma_xy = 10.*mm;//2.5;// ~6 mm (FWHM)
  G4double x = G4RandGauss::shoot(0.,sigma_xy);
  G4double y = G4RandGauss::shoot(0.,sigma_xy);
  G4double z = G4RandGauss::shoot(0.,sigma_xy);//15.0*mm;
  G4ThreeVector dir;
  dir=(G4ThreeVector(0,0,0.0*mm)-G4ThreeVector(x,y,z));
  dir=dir/dir.mag();
  particleGun->SetParticlePosition(G4ThreeVector(x,y,z));
  particleGun->SetParticleMomentumDirection(dir);
  G4cout << x << '\t' << y << '\t' << z << " position [mm] of Primaries" << G4endl;
  G4cout << dir.x()<<'\t'<<dir.y()<<'\t'<<dir.z()<<'\t' <<" direction of Primaries" << G4endl;
  particleGun->GeneratePrimaryVertex(anEvent);
}

void AXPETPrimaryGeneratorAction::SetOptPhotonPolar()
{
 G4double angle = G4UniformRand() * 360.0*deg;
 SetOptPhotonPolar(angle);
}

void AXPETPrimaryGeneratorAction::SetOptPhotonPolar(G4double angle)
{
 if (particleGun->GetParticleDefinition()->GetParticleName() != "opticalphoton")
   {
     G4cout << "--> warning from PrimaryGeneratorAction::SetOptPhotonPolar() :"
               "the particleGun is not an opticalphoton" << G4endl;
     return;
   }
               
 G4ThreeVector normal (1., 0., 0.);
 G4ThreeVector kphoton = particleGun->GetParticleMomentumDirection();
 G4ThreeVector product = normal.cross(kphoton); 
 G4double modul2       = product*product;
 
 G4ThreeVector e_perpend (0., 0., 1.);
 if (modul2 > 0.) e_perpend = (1./std::sqrt(modul2))*product; 
 G4ThreeVector e_paralle    = e_perpend.cross(kphoton);
 
 G4ThreeVector polar = std::cos(angle)*e_paralle + std::sin(angle)*e_perpend;
 particleGun->SetParticlePolarization(polar);
}