G4ErrorEnergyLoss.cc

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#include "G4ErrorEnergyLoss.hh"
#include "G4EnergyLossForExtrapolator.hh"
#include "G4ErrorPropagatorData.hh"
 
//-------------------------------------------------------------------
G4ErrorEnergyLoss::G4ErrorEnergyLoss(const G4String& processName, 
                     G4ProcessType type)
  : G4VContinuousProcess(processName, type)
{
  if (verboseLevel>2) {
    G4cout << GetProcessName() << " is created " << G4endl;
  }
 
  theELossForExtrapolator = new G4EnergyLossForExtrapolator;
  theStepLimit = 1.*CLHEP::mm;
}
 
//-------------------------------------------------------------------
void G4ErrorEnergyLoss::InstantiateEforExtrapolator()
{}
 
//-------------------------------------------------------------------
G4ErrorEnergyLoss::~G4ErrorEnergyLoss() 
{
  delete theELossForExtrapolator;
}
 
//-------------------------------------------------------------------
 
G4bool G4ErrorEnergyLoss::IsApplicable(const G4ParticleDefinition& aParticleType)
{
   return (aParticleType.GetPDGCharge() != 0);
}
 
//-------------------------------------------------------------------
G4VParticleChange*
G4ErrorEnergyLoss::AlongStepDoIt(const G4Track& aTrack, const G4Step& aStep)
{
  aParticleChange.Initialize(aTrack);
 
  G4ErrorPropagatorData* g4edata = G4ErrorPropagatorData::GetErrorPropagatorData();
 
  G4double kinEnergyStart = aTrack.GetKineticEnergy();
  G4double step_length  = aStep.GetStepLength();
 
  const G4Material* aMaterial = aTrack.GetMaterial();
  const G4ParticleDefinition* aParticleDef = aTrack.GetDynamicParticle()->GetDefinition();
  G4double kinEnergyEnd = kinEnergyStart;
 
  // backward - energy increased
  if( g4edata->GetMode() == G4ErrorMode(G4ErrorMode_PropBackwards) ) {
    kinEnergyEnd = theELossForExtrapolator->EnergyBeforeStep( kinEnergyStart, 
                                  step_length, 
                                  aMaterial, 
                                  aParticleDef );
    G4double kinEnergyHalfStep = (kinEnergyStart + kinEnergyEnd) * 0.5;
 
#ifdef G4VERBOSE
  if(G4ErrorPropagatorData::verbose() >= 3 ) 
    G4cout << " G4ErrorEnergyLoss FWD  end " << kinEnergyEnd 
       << " halfstep " << kinEnergyHalfStep << G4endl;
#endif
 
    //--- rescale to energy lost at 1/2 step
    kinEnergyEnd = theELossForExtrapolator->EnergyBeforeStep( kinEnergyHalfStep, 
                                  step_length, 
                                  aMaterial, 
                                  aParticleDef );
    kinEnergyEnd = kinEnergyStart - (kinEnergyHalfStep - kinEnergyEnd );
 
    // forward - energy decreased
  } else {
    kinEnergyEnd = theELossForExtrapolator->EnergyAfterStep( kinEnergyStart, 
                                 step_length, 
                                 aMaterial, 
                                 aParticleDef );
    G4double kinEnergyHalfStep = (kinEnergyStart + kinEnergyEnd) * 0.5;
#ifdef G4VERBOSE
  if(G4ErrorPropagatorData::verbose() >= 3 ) 
    G4cout << " G4ErrorEnergyLoss BCKD  end " << kinEnergyEnd 
       << " halfstep " << kinEnergyHalfStep << G4endl;
#endif
 
    //--- rescale to energy lost at 1/2 step
    kinEnergyEnd = theELossForExtrapolator->EnergyAfterStep( kinEnergyHalfStep, 
                                 step_length, 
                                 aMaterial, 
                                 aParticleDef );
    kinEnergyEnd = kinEnergyStart - (kinEnergyHalfStep - kinEnergyEnd );
  }
 
  G4double edepo = kinEnergyEnd - kinEnergyStart;
 
#ifdef G4VERBOSE
  if( G4ErrorPropagatorData::verbose() >= 2 ) 
    G4cout << "AlongStepDoIt Estart= " << kinEnergyStart << " Eend " << kinEnergyEnd 
       << " Ediff " << kinEnergyStart-kinEnergyEnd << " step= " << step_length 
       << " mate= " << aMaterial->GetName() 
       << " particle= " << aParticleDef->GetParticleName() << G4endl;
#endif
 
  aParticleChange.ClearDebugFlag();
  aParticleChange.ProposeLocalEnergyDeposit( edepo );
  aParticleChange.SetNumberOfSecondaries(0);
 
  aParticleChange.ProposeEnergy( kinEnergyEnd );
  
  return &aParticleChange;
}
 
 
//-------------------------------------------------------------------
G4double G4ErrorEnergyLoss::GetContinuousStepLimit(const G4Track& aTrack,
                    G4double, G4double, G4double& )
{ 
  G4double ekin = aTrack.GetKineticEnergy();
  const G4Material* mat = aTrack.GetMaterial();
  const G4ParticleDefinition* part = 
    aTrack.GetDynamicParticle()->GetDefinition();
  G4double range = theELossForExtrapolator->ComputeRange(ekin, part, mat);
  G4double delta = std::max(range*theFractionLimit, theStepLimit);
#ifdef G4VERBOSE
  if(G4ErrorPropagatorData::verbose() >= 2 ) {
    G4cout << " G4ErrorEnergyLoss: limiting Step " << delta 
       << " energy(GeV) " << ekin / CLHEP::GeV 
       << " for " << part->GetParticleName() << G4endl;
  }
#endif
  return delta;
}