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// $Id: G4PenelopeCompton.hh,v 1.5 2003/02/24 00:36:10 pia Exp $
// GEANT4 tag $Name: geant4-05-01 $
//
// Author: Luciano Pandola
//
// History:
// -----------
// 05 Dec 2002   L. Pandola   1st implementation
// 12 Feb 2003   MG Pia       const argument in SelectRandomAtomForCompton
// 14 Feb 2003   MG Pia       Modified some variables to lowercase initial 
//
// -------------------------------------------------------------------

// Class description:
// Low Energy Electromagnetic Physics, Compton Scattering
// Penelope Model
// -------------------------------------------------------------------

#ifndef G4PENELOPECOMPTON_HH
#define G4PENELOPECOMPTON_HH 1

#include "globals.hh"
#include "G4VDiscreteProcess.hh"

class G4Track;
class G4Step;
class G4ParticleDefinition;
class G4VParticleChange;
class G4VEMDataSet;
class G4VRangeTest;
class G4Material;

class G4PenelopeCompton : public G4VDiscreteProcess {

public:
  
  G4PenelopeCompton(const G4String& processName ="PenCompton");
  
  ~G4PenelopeCompton();

  G4bool IsApplicable(const G4ParticleDefinition& definition);
  
  void BuildPhysicsTable(const G4ParticleDefinition& photon);
 
  G4VParticleChange* PostStepDoIt(const G4Track& aTrack, const G4Step& aStep);
 
  // For testing purpose only
  G4double DumpMeanFreePath(const G4Track& aTrack, 
			    G4double previousStepSize, 
			    G4ForceCondition* condition) 
  { return GetMeanFreePath(aTrack, previousStepSize, condition); }

protected:

  G4double GetMeanFreePath(const G4Track& aTrack, 
			   G4double previousStepSize, 
			   G4ForceCondition* condition);

private: 

  // Hide copy constructor and assignment operator as private 
  G4PenelopeCompton& operator=(const G4PenelopeCompton& right);
  G4PenelopeCompton(const G4PenelopeCompton& );

  void ReadData();

  G4double CrossSection(G4double energy,G4int Z);
  G4double DifferentialCrossSection (G4double cdt);

  G4double lowEnergyLimit;  // low energy limit  applied to the process
  G4double highEnergyLimit; // high energy limit applied to the process

  G4VEMDataSet* meanFreePathTable;
  G4VRangeTest* rangeTest;

  const G4double intrinsicLowEnergyLimit; // intrinsic validity range
  const G4double intrinsicHighEnergyLimit;

  G4double energyForIntegration; //for numerical integration of
  G4int ZForIntegration;// analytical cross section

  G4std::vector<G4DataVector*> *ionizationEnergy;
  G4std::vector<G4DataVector*> *hartreeFunction;
  G4std::vector<G4DataVector*> *occupationNumber;
  
  G4int SelectRandomAtomForCompton(const G4Material* material,G4double e) const;

  const G4int nBins; //for building cross section table

  G4std::vector<G4VEMDataSet*>* matCrossSections; //for random choice of atom
};

#endif