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// $Id: G4LivermorePolarizedRayleighModel.hh,v 1.3 2009/05/02 15:20:52 sincerti Exp $
// GEANT4 tag $Name: geant4-09-04-beta-cand-01 $
//

#ifndef G4LivermorePolarizedRayleighModel_h
#define G4LivermorePolarizedRayleighModel_h 1

#include "G4VEmModel.hh"
#include "G4ParticleChangeForGamma.hh"
#include "G4CrossSectionHandler.hh"
#include "G4LogLogInterpolation.hh"
#include "G4CompositeEMDataSet.hh"
#include "G4Gamma.hh"

class G4LivermorePolarizedRayleighModel : public G4VEmModel
{

public:

  G4LivermorePolarizedRayleighModel(const G4ParticleDefinition* p = 0, 
		     const G4String& nam = "LivermorePolarizedRayleigh");

  virtual ~G4LivermorePolarizedRayleighModel();

  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;

private:

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

  G4VCrossSectionHandler* crossSectionHandler;
  G4VEMDataSet* formFactorData;

  //   Generates \f$cos \left ( \theta\right )\f$ of the scattered photon
  //   incomingPhotonEnergy The energy of the incoming photon
  //   zAtom Atomic number
  //   \f$cos \left ( \theta\right )\f$
  G4double GenerateCosTheta(G4double incomingPhotonEnergy, G4int zAtom) const;
   
  //   Generates \f$\phi\f$ of the scattered photon
  //   cosTheta \f$cos \left ( \theta\right )\f$ of the scattered photon
  //    \f$\phi\f$
  G4double GeneratePhi(G4double cosTheta) const;

  //   Generates the polarization direction \f$\beta\f$ in the plane x, y relative to the x direction
  //   \f$\beta\f$
  G4double GeneratePolarizationAngle(void) const;
 
  G4ThreeVector GetPhotonPolarization(const G4DynamicParticle&  photon);

  G4LivermorePolarizedRayleighModel & operator=(const  G4LivermorePolarizedRayleighModel &right);
  G4LivermorePolarizedRayleighModel(const  G4LivermorePolarizedRayleighModel&);

};

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#endif
