src/BDSContinuousSR.cc

//
//  Synchrotron radiation energy loss process
//

#include <list>



#include "BDSGlobalConstants.hh" 
#include "BDSContinuousSR.hh"
#include "G4ios.hh"
#include "G4UnitsTable.hh"

#include "BDSAcceleratorComponent.hh"
#include "BDSBeamline.hh"


BDSContinuousSR::BDSContinuousSR(const G4String& processName)
  : G4VDiscreteProcess(processName)
     // initialization
{

  G4cout<<"initializing contSR"<<G4endl;

  nExpConst=5*fine_structure_const/(2*sqrt(3.0))/electron_mass_c2;
  CritEngFac=3./2.*hbarc/pow(electron_mass_c2,3);

} 
 

G4VParticleChange* 
BDSContinuousSR::PostStepDoIt(const G4Track& trackData,
                                     const G4Step& stepData)
{
  aParticleChange.Initialize(trackData);

  G4double eEnergy=trackData.GetTotalEnergy();

  G4double R=BDSLocalRadiusOfCurvature;

  G4double NewKinEnergy = trackData.GetKineticEnergy();
 
  G4double GamEnergy=0;

  aParticleChange.SetNumberOfSecondaries(0);

  if(fabs(R)>0) {
    G4double l = trackData.GetStep()->GetStepLength();
    const G4DynamicParticle* aParticle = trackData.GetDynamicParticle();
    G4double mass = aParticle->GetMass();
    G4double gamma = 1.e-3 * eEnergy / mass; // in 1.e3 units
    
    G4double r0 = 2.817940325e-3*m; // classical electron radius in 1..e-12 units

    // G4cout<<"mass="<<mass<<G4endl;
//     G4cout<<"energy="<<eEnergy<<G4endl;
//     G4cout<<"gamma="<<gamma<<G4endl;
//     G4cout<<"R="<<R<<G4endl;  
   
    // energy loss (in MeV)
    GamEnergy = l * (gamma * gamma * gamma * gamma ) * 2. * r0 * mass / ( 3. * R * R) ;
    
    //G4cout<<"constSr : poststepdoit, l= "<<l<<" energy loss =" << GamEnergy  <<" MeV"<<G4endl;
  }

  NewKinEnergy -= GamEnergy;

  if(GamEnergy>0)
    {
      
      if (NewKinEnergy > 0.)
        {
          //
          // Update the incident particle 
          aParticleChange.ProposeEnergy(NewKinEnergy);
        } 
      else
        { 
          aParticleChange.ProposeEnergy( 0. );
          aParticleChange.ProposeLocalEnergyDeposit (0.);
          G4double charge= trackData.GetDynamicParticle()->GetCharge();
          if (charge<0.) aParticleChange.ProposeTrackStatus(fStopAndKill);
          else       aParticleChange.ProposeTrackStatus(fStopButAlive);
        }
      
    }
  
  return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
}


BDSContinuousSR::~BDSContinuousSR(){
}

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