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// $Id: G4ComptonScattering.icc,v 1.8 2001/09/21 09:50:53 maire Exp $
// GEANT4 tag $Name: geant4-05-02-patch-01 $
//
//------------------ G4ComptonScattering physics process -----------------------
//                   by Michel Maire, April 1996
// 
// 10-06-96, updated by M.Maire
// 06-01-97, crossection table + meanfreepath table, M.Maire
// 12-03-97, new Physics scheme
// 21-11-97, change for lowest energy limit default action
// 15-12-98, return DBL_MAX below LowestEnergyLimit
// 28-05-01, V.Ivanchenko minor changes to provide ANSI -wall compilation
// 17-09-01, migration of Materials to pure STL (mma) 
//------------------------------------------------------------------------------


//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

inline G4bool G4ComptonScattering::IsApplicable(
                                         const G4ParticleDefinition& particle)
{
   return ( &particle == G4Gamma::Gamma() ); 
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

inline G4double G4ComptonScattering::GetMeanFreePath(const G4Track& aTrack,
                                                     G4double,
                                                     G4ForceCondition*)

// returns the gamma mean free path in GEANT4 internal units

{
   const G4DynamicParticle* aDynamicGamma = aTrack.GetDynamicParticle();
   G4double GammaEnergy = aDynamicGamma->GetKineticEnergy();
   G4Material* aMaterial = aTrack.GetMaterial();

   G4double MeanFreePath;
   G4bool isOutRange;

   if (GammaEnergy > HighestEnergyLimit || GammaEnergy < LowestEnergyLimit)
     MeanFreePath = DBL_MAX;
   else
     MeanFreePath = (*theMeanFreePathTable)(aMaterial->GetIndex())->
                                       GetValue(GammaEnergy, isOutRange);
   return MeanFreePath;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

inline G4double G4ComptonScattering::ComputeMeanFreePath(G4double GammaEnergy,
                                                         G4Material* aMaterial)

// returns the gamma mean free path in GEANT4 internal units

{
  const G4ElementVector* theElementVector = aMaterial->GetElementVector() ;
  const G4double* NbOfAtomsPerVolume = aMaterial->GetVecNbOfAtomsPerVolume();

  G4double SIGMA = 0.;

  for ( size_t elm=0 ; elm < aMaterial->GetNumberOfElements() ; elm++ )
      {             
        SIGMA += NbOfAtomsPerVolume[elm] * 
                 ComputeCrossSectionPerAtom(GammaEnergy,
                                            (*theElementVector)[elm]->GetZ());
      }       
  return SIGMA > DBL_MIN ? 1./SIGMA : DBL_MAX;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
inline G4double G4ComptonScattering::GetMicroscopicCrossSection(
                                            G4DynamicParticle* aDynamicGamma,
                                            G4Element*         anElement)
 
// gives the microscopic total cross section in GEANT4 internal units

{
   G4double crossSection;
   G4double GammaEnergy = aDynamicGamma->GetKineticEnergy();
   G4bool isOutRange ;
   if (GammaEnergy < LowestEnergyLimit || GammaEnergy > HighestEnergyLimit)
      crossSection = 0.;
   else
      crossSection = (*theCrossSectionTable)(anElement->GetIndex())->
                                       GetValue(GammaEnergy, isOutRange);

   return crossSection;
} 

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......