source: trunk/examples/advanced/Rich/src/HpdSiEnergyLoss.cc@ 1313

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// Rich advanced example for Geant4
// HpdSiEnergyLoss.cc for Rich of LHCb
// History:
// Created: Sajan Easo (Sajan.Easo@cern.ch)
// Revision: Patricia Mendez (Patricia.Mendez@cern.ch)
/////////////////////////////////////////////////////////////////////////////
#include "HpdSiEnergyLoss.hh"
#include "G4Material.hh"
#include "Randomize.hh"
#include "RichTbMaterialParameters.hh"
#include "RichTbAnalysisManager.hh"

HpdSiEnergyLoss::HpdSiEnergyLoss(const G4String& materialName,
                                 const G4String& processName)
  : G4VEnergyLoss(processName),
    MinKineticEnergy(1.*eV),MipEnergy(30000.0*eV),
    finalRangeforStep(0.15*mm)  { 
  ElossMaterialName= materialName;
  
  const G4MaterialTable* theMaterialTable = G4Material::GetMaterialTable();
  G4int numberOfMat = G4Material::GetNumberOfMaterials();
  
  G4int iMat=0;
  for(iMat=0;iMat<numberOfMat;iMat++) {
    if ( materialName == (*theMaterialTable)[iMat]->GetName()){
      fMatIndex=(*theMaterialTable)[iMat]->GetIndex();
      break;
    }
    
  }
  if(iMat >= numberOfMat ) {
    G4Exception("Invalid material Name in HpdSiEnergyLoss constructor" );
  }
}

HpdSiEnergyLoss::~HpdSiEnergyLoss() { }

G4bool HpdSiEnergyLoss::IsApplicable(const G4ParticleDefinition& 
                                     aParticleType) {
   return(aParticleType.GetPDGCharge()!= 0.);
}

G4double HpdSiEnergyLoss::GetContinuousStepLimit(const G4Track& track,
                                 G4double,
                                 G4double,
                                 G4double& ){

  G4double  RangeForStep =  finalRangeforStep;

  if( fMatIndex != G4int(track.GetMaterial() -> GetIndex()) ) { 
    RangeForStep = DBL_MAX;
  }

  return RangeForStep;
}

G4double  HpdSiEnergyLoss::GetMeanFreePath(const G4Track&,
                         G4double,
                         G4ForceCondition* condition) {
  // return infinity so that it does nothing.
  *condition = NotForced;
  return DBL_MAX;

}

G4VParticleChange*  HpdSiEnergyLoss::PostStepDoIt(const G4Track& aTrack,
                                 const G4Step& aStep) {
  // Do nothing
   aParticleChange.Initialize(aTrack) ;
  return G4VContinuousDiscreteProcess::PostStepDoIt(aTrack,aStep);
   
}

G4VParticleChange* HpdSiEnergyLoss::AlongStepDoIt(const G4Track& aTrack,
                                 const G4Step&) {


#ifdef G4ANALYSIS_USE
  RichTbAnalysisManager * analysis = RichTbAnalysisManager::getInstance();
#endif


  aParticleChange.Initialize(aTrack);
  G4int aMaterialIndex = aTrack.GetMaterial()->GetIndex();
  if(fMatIndex != aMaterialIndex ) {
    return &aParticleChange;
  }

  const G4DynamicParticle* aParticle = aTrack.GetDynamicParticle();
  G4double aKinEnergyInit = aParticle->GetKineticEnergy();
  G4double Eloss, aKinEnergyFinal;
  if(aKinEnergyInit < MinKineticEnergy ) {  Eloss=0.0 ; }
  else if( aKinEnergyInit < MipEnergy ) {Eloss= aKinEnergyInit ;}
  else { Eloss = MipEnergy; }
 
  aKinEnergyFinal=aKinEnergyInit-Eloss;


  //In the G4example the backscattering is implemented in
  //an adhoc manner as done  below. It simply causes an
  // efficiency loss.

  G4double bckratio;
  if( SignalToNoiseInData > 0.0 ){
    bckratio =  NsigmaInPedCut/ SignalToNoiseInData ;

  }
  G4double Effs = 1.0 -  backscaprob * bckratio;
  G4double Randbsk =  G4UniformRand();
  if(Randbsk <= Effs && Eloss > 0.0 ) {
           aParticleChange.ProposeLocalEnergyDeposit(Eloss);

#ifdef G4ANALYSIS_USE
  
           analysis->bumpNumHitInSi();

#endif

    // G4StepPoint* pPreStepPoint  = aStep.GetPreStepPoint();
    // G4String tpreVol = pPreStepPoint -> GetPhysicalVolume()->GetName();
    // G4int tpreVP =  pPreStepPoint -> GetPhysicalVolume()->GetCopyNo();
  }
  if (aKinEnergyFinal <= MinKineticEnergy ) {
       aParticleChange.ProposeTrackStatus(fStopAndKill);
  
   }else { 
     aParticleChange.ProposeEnergy(aKinEnergyFinal);

   }
  return &aParticleChange;

}