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//
// -------------------------------------------------------------------
//
// GEANT4 Class header file
//
//
// File name:     G4eBremsstrahlungModel
//
// Author:        Vladimir Ivanchenko on base of Laszlo Urban code
// 
// Creation date: 07.01.2002
//
// Modifications: 

//
// Class Description: 
//
// Implementation of energy loss for gamma emission by electrons and 
// positrons

// -------------------------------------------------------------------
//

#ifndef G4eBremsstrahlungModel_h
#define G4eBremsstrahlungModel_h 1

#include "G4VEmModel.hh"

class G4eBremsstrahlungModel : public G4VEmModel
{

public:

  G4eBremsstrahlungModel(const G4ParticleDefinition* p = 0);

  ~G4eBremsstrahlungModel();

  G4double HighEnergyLimit(const G4ParticleDefinition* p,
                           const G4Material*);
 
  G4double LowEnergyLimit(const G4ParticleDefinition* p,
                          const G4Material*);

  void SetHighEnergyLimit(const G4Material*, G4double e) {highKinEnergy = e;};
 
  void SetLowEnergyLimit(const G4Material*, G4double e) {lowKinEnergy = e;};

  G4double MinEnergyCut(const G4ParticleDefinition*,
                        const G4Material*);
 
  G4bool IsInCharge(const G4ParticleDefinition*,
	            const G4Material*);

  G4double ComputeDEDX(const G4Material*,
                       const G4ParticleDefinition*,
                             G4double kineticEnergy,
                             G4double cutEnergy);

  G4double CrossSection(const G4Material*,
                        const G4ParticleDefinition*,
                              G4double kineticEnergy,
                              G4double cutEnergy,
                              G4double maxEnergy);

  G4std::vector<G4DynamicParticle*>* SampleSecondary(
                                const G4Material*,
                                const G4DynamicParticle*,
                                      G4double tmin,
                                      G4double maxEnergy);
  
  void   SetLPMflag(G4bool val) {theLPMflag = val;};
  G4bool LPMflag() const {return theLPMflag;};

  virtual G4double MaxSecondaryEnergy(
				const G4DynamicParticle* dynParticle); 
protected:

  virtual G4double MaxSecondaryEnergy(const G4ParticleDefinition*,
    				            G4double kineticEnergy); 

private:

  void SetParticle(const G4ParticleDefinition* p);

  G4double ComputeBremLoss(G4double Z, G4double tkin, G4double cut, G4double x);  

  G4double PositronCorrFactorLoss(G4double Z, G4double tkin, G4double cut);

  G4double PositronCorrFactorSigma(G4double Z, G4double tkin, G4double cut);

  G4double CrossSectionPerAtom(G4double tkin, G4double Z, G4double cut);

  void ComputePartialSumSigma(const G4Material* material, G4double tkin,
                                                          G4double cut);

  const G4Element* SelectRandomAtom(const G4Material* material) const;

  G4double SupressionFunction(const G4Material* material, G4double tkin, 
                                    G4double gammaEnergy);

  G4double ScreenFunction1(G4double ScreenVariable);

  G4double ScreenFunction2(G4double ScreenVariable);

  // hide assignment operator 
  G4eBremsstrahlungModel & operator=(const  G4eBremsstrahlungModel &right);
  G4eBremsstrahlungModel(const  G4eBremsstrahlungModel&);

  const G4ParticleDefinition* particle;
  G4double highKinEnergy;
  G4double lowKinEnergy;
  G4double minThreshold;
  G4double probsup;
  G4double MigdalConstant;
  G4double LPMconstant;
  G4bool   isElectron;
  G4bool   theLPMflag;
  const G4Material* oldMaterial;
  G4std::vector<G4DataVector*> partialSumSigma;

};

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

inline G4double G4eBremsstrahlungModel::ScreenFunction1(G4double ScreenVariable)

// compute the value of the screening function 3*PHI1 - PHI2

{
   G4double screenVal;

   if (ScreenVariable > 1.)
     screenVal = 42.24 - 8.368*log(ScreenVariable+0.952);
   else
     screenVal = 42.392 - ScreenVariable* (7.796 - 1.961*ScreenVariable);

   return screenVal;
} 

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

inline 
G4double G4eBremsstrahlungModel::ScreenFunction2(G4double ScreenVariable)

// compute the value of the screening function 1.5*PHI1 - 0.5*PHI2

{
   G4double screenVal;

   if (ScreenVariable > 1.)
     screenVal = 42.24 - 8.368*log(ScreenVariable+0.952);
   else
     screenVal = 41.734 - ScreenVariable* (6.484 - 1.250*ScreenVariable);

   return screenVal;
} 

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

inline 
G4double G4eBremsstrahlungModel::MaxSecondaryEnergy(
				 const G4DynamicParticle* dynParticle)
{
  return dynParticle->GetKineticEnergy();
} 

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

inline 
G4double G4eBremsstrahlungModel::MaxSecondaryEnergy(
                                 const G4ParticleDefinition*,
    				       G4double kineticEnergy)
{
  return kineticEnergy;
}

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

#endif