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// $Id$
//
// Authors: G.Depaola & F.Longo
//

#ifndef G4LivermorePolarizedGammaConversionModel_h
#define G4LivermorePolarizedGammaConversionModel_h 1

#include "G4VEmModel.hh"
#include "G4LPhysicsFreeVector.hh"

//#include "G4Electron.hh"
//#include "G4Positron.hh"
class G4ParticleChangeForGamma;



class G4LivermorePolarizedGammaConversionModel : public G4VEmModel
{

public:

  G4LivermorePolarizedGammaConversionModel(const G4ParticleDefinition* p = 0, 
					     const G4String& nam = "LivermorePolarizedGammaConversion");
  
  virtual ~G4LivermorePolarizedGammaConversionModel();
  
  virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&);

  virtual void InitialiseLocal(const G4ParticleDefinition*, 
			       G4VEmModel* masterModel);
  
  virtual void InitialiseForElement(const G4ParticleDefinition*, G4int Z);

  virtual G4double ComputeCrossSectionPerAtom(
					      const G4ParticleDefinition*,
					      G4double kinEnergy, 
					      G4double Z, 
					      G4double A=0, 
					      G4double cut=0,
					      G4double emax=DBL_MAX);
  
  virtual void SampleSecondaries(std::vector<G4DynamicParticle*>*,
				 const G4MaterialCutsCouple*,
				 const G4DynamicParticle*,
				 G4double tmin,
				 G4double maxEnergy);

  virtual G4double MinPrimaryEnergy(const G4Material*,
				    const G4ParticleDefinition*,
				    G4double); 
  
private:
  
  G4ParticleChangeForGamma* fParticleChange;

  G4double lowEnergyLimit;  
  
  //  G4double highEnergyLimit; 
  G4bool isInitialised;
  G4int verboseLevel;


  void ReadData(size_t Z, const char* path = 0);
  
  G4double ScreenFunction1(G4double screenVariable);
  G4double ScreenFunction2(G4double screenVariable);
  
  // specific methods for polarization 
  
  G4ThreeVector GetRandomPolarization(G4ThreeVector& direction0); // Random Polarization
  G4ThreeVector GetPerpendicularPolarization(const G4ThreeVector& direction0, const G4ThreeVector& polarization0) const;
  G4ThreeVector SetPerpendicularVector(G4ThreeVector& a); // temporary
  void SystemOfRefChange(G4ThreeVector& direction0, G4ThreeVector& direction1, 
			 G4ThreeVector& polarization0);

  // Gamma Conversion methods 


  G4double SetPhi(G4double);
  G4double SetPsi(G4double, G4double); //

  void SetTheta(G4double*, G4double*, G4double);

  G4double Poli(G4double , G4double, G4double, G4double);
  G4double Fln(G4double, G4double, G4double);

  G4double Encu(G4double*, G4double*, G4double);

  G4double Flor(G4double*, G4double);
  G4double Glor(G4double*, G4double);

  G4double Fdlor(G4double*, G4double);
  G4double Fintlor(G4double*, G4double);
  G4double Finvlor(G4double*, G4double,G4double);

  G4double Ftan(G4double*, G4double);

  //G4double Gtan(G4double*, G4double);

  G4double Fdtan(G4double*, G4double);
  G4double Finttan(G4double*, G4double);
  G4double Finvtan(G4double*, G4double, G4double);

  G4double smallEnergy;
  G4double Psi, Phi;

  
  G4LivermorePolarizedGammaConversionModel & operator=(const  G4LivermorePolarizedGammaConversionModel &right);
  G4LivermorePolarizedGammaConversionModel(const  G4LivermorePolarizedGammaConversionModel&);

  static G4int maxZ;
  static G4LPhysicsFreeVector* data[100]; // 100 because Z range is 1-99

};

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

#endif
