// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: G4LowEnergyPhotoElectric.hh,v 1.14 2000/11/03 10:29:51 pia Exp $
// GEANT4 tag $Name: geant4-03-00 $
//
// 
// ------------------------------------------------------------
//      GEANT 4 class header file
//      CERN Geneva Switzerland
//
//      For information related to this code contact:
//      CERN, CN Division, ASD group
//      ------------ G4LowEnergyPhotoElectric physics process ------
//                   by A.Forti  1999/03/02
//
// Class description:
// Low Energy Electromagnetic process, Photoelectric effect
// Further documentation available from http://www.ge.infn.it/geant4/lowE

// ************************************************************

#ifndef G4LowEnergyPhotoElectric_h
#define G4LowEnergyPhotoElectric_h 1

// Base Class Headers
#include "G4VDiscreteProcess.hh"

// Contained Variables Headers
#include "G4LowEnergyUtilities.hh"
#include "G4Gamma.hh"

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

typedef G4FirstLevel oneShellTable;
typedef G4SecondLevel oneAtomTable;
typedef G4ThirdLevel allAtomTable;

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

class G4LowEnergyPhotoElectric : public G4VDiscreteProcess

{
  
public:
  
  G4LowEnergyPhotoElectric(const G4String& processName ="LowEnPhotoElec");
  
 ~G4LowEnergyPhotoElectric();

  G4bool IsApplicable(const G4ParticleDefinition&);
  
  void SetCutForLowEnSecPhotons(G4double);

  //  void SetCutForLowEnSecElectrons(G4double);

  void BuildPhysicsTable(const G4ParticleDefinition& PhotonType);
  
  G4double GetMeanFreePath(const G4Track& aTrack, 
			   G4double previousStepSize, 
			   G4ForceCondition* condition);

  G4double GetCrossSection(G4DynamicParticle* aDynamicGamma,
			    G4Element* anElement);

  inline G4double GetTransitionShell(G4int k){return(thePrimShVec(k));};

  G4VParticleChange* PostStepDoIt(const G4Track& aTrack, const G4Step& aStep);
  
protected:  

  virtual G4double ComputeCrossSection(const G4double AtomicNumber,
				       const G4double IncEnergy);  
  void BuildCrossSectionTable();
  void BuildShellCrossSectionTable();
  void BuildBindingEnergyTable();
  void BuildFluorTransitionTable();
  void BuildMeanFreePathTable();
  void BuildZVec();

private:

  G4int SelectRandomShell(const G4int AtomIndex, const G4double IncEnergy);
  
  G4Element* SelectRandomAtom(const G4DynamicParticle* aDynamicPhoton, 
			      G4Material* aMaterial);

  G4bool SelectRandomTransition(G4int, G4double*, const oneAtomTable*);

private:
  
  // hide assignment operator as private 
  G4LowEnergyPhotoElectric& operator=(const G4LowEnergyPhotoElectric &right);
  G4LowEnergyPhotoElectric(const G4LowEnergyPhotoElectric& );
     
private:

  G4SecondLevel* theCrossSectionTable;    
  G4PhysicsTable* theMeanFreePathTable;

  allAtomTable* allAtomShellCrossSec;
  allAtomTable* theFluorTransitionTable;
  G4SecondLevel* theBindingEnergyTable;   
  G4DataVector thePrimShVec;
  G4Data* ZNumVec;
  G4Data* ZNumVecFluor;

  G4LowEnergyUtilities util;

  G4double LowestEnergyLimit;      
  G4double HighestEnergyLimit;     
  G4int NumbBinTable;              
  G4double CutForLowEnergySecondaryPhotons;
  G4double MeanFreePath;           
};

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

#include "G4LowEnergyPhotoElectric.icc"

#endif