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// $Id: G4LivermorePolarizedGammaConversionModel.hh,v 1.1 2009/10/30 14:52:05 flongo Exp $
// GEANT4 tag $Name: geant4-09-04-ref-00 $
//

#ifndef G4LivermorePolarizedGammaConversionModel_h
#define G4LivermorePolarizedGammaConversionModel_h 1

#include "G4VEmModel.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4ParticleChangeForGamma.hh"
#include "G4CrossSectionHandler.hh"
#include "G4LogLogInterpolation.hh"
#include "G4CompositeEMDataSet.hh"
#include "G4ProductionCutsTable.hh"
#include "G4ForceCondition.hh"


class G4LivermorePolarizedGammaConversionModel : public G4VEmModel
{

public:

  G4LivermorePolarizedGammaConversionModel(const G4ParticleDefinition* p = 0, 
		                   const G4String& nam = "LivermorePolarizedGammaConversion");

  virtual ~G4LivermorePolarizedGammaConversionModel();

  virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&);

  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);

protected:

  G4ParticleChangeForGamma* fParticleChange;

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

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

  G4VEMDataSet* meanFreePathTable;
  G4VCrossSectionHandler* crossSectionHandler;


  // 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); //

  G4double ScreenFunction1(G4double screenVariable);
  G4double ScreenFunction2(G4double screenVariable);
  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&);

};

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#endif