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// $Id$
//
// -------------------------------------------------------------------
//
// GEANT4 Class header file
//
//
// File name:     G4eCoulombScatteringModel
//
// Author:        Vladimir Ivanchenko 
//
// Creation date: 19.02.2006
//
// Modifications:
// 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the
//          logic of building - only elements from G4ElementTable
// 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim
// 19.08.06 V.Ivanchenko add inline function ScreeningParameter and
//                       make some members protected
// 09.10.07 V.Ivanchenko reorganized methods, add cut dependence in scattering off e- 
// 09.06.08 V.Ivanchenko add SelectIsotope and sampling of the recoil ion 
// 17.06.09 C.Consoalndi modified SetupTarget method - remove kinFactor
// 27.05.10 V.Ivanchenko added G4WentzelOKandVIxSection class to
//              compute cross sections and sample scattering angle
//				       
//
// Class Description:
//
// Implementation of eCoulombScattering of pointlike charge particle 
// on Atomic Nucleus for interval of scattering anles in Lab system 
// thetaMin - ThetaMax, nucleus recoil is neglected.
//   The model based on analysis of J.M.Fernandez-Varea et al. 
// NIM B73(1993)447 originated from G.Wentzel Z.Phys. 40(1927)590 with 
// screening parameter from H.A.Bethe Phys. Rev. 89 (1953) 1256.
// 

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

#ifndef G4eCoulombScatteringModel_h
#define G4eCoulombScatteringModel_h 1

#include "G4VEmModel.hh"
#include "globals.hh"
#include "G4MaterialCutsCouple.hh"
#include "G4WentzelOKandVIxSection.hh"

class G4ParticleChangeForGamma;
class G4ParticleDefinition;
class G4ParticleTable;
class G4NistManager;

class G4eCoulombScatteringModel : public G4VEmModel
{

public:

  G4eCoulombScatteringModel(const G4String& nam = "eCoulombScattering");
 
  virtual ~G4eCoulombScatteringModel();

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

  virtual G4double ComputeCrossSectionPerAtom(
                                const G4ParticleDefinition*,
				G4double kinEnergy, 
				G4double Z, 
				G4double A, 
				G4double cut,
				G4double emax);

  virtual void SampleSecondaries(std::vector<G4DynamicParticle*>*,
				 const G4MaterialCutsCouple*,
				 const G4DynamicParticle*,
				 G4double tmin,
				 G4double maxEnergy);

  // defines low energy limit of the model
  inline void SetLowEnergyThreshold(G4double val);

  // user definition of low-energy threshold of recoil
  inline void SetRecoilThreshold(G4double eth);

protected:

  inline void DefineMaterial(const G4MaterialCutsCouple*);

  inline void SetupParticle(const G4ParticleDefinition*);

private:

  // hide assignment operator
  G4eCoulombScatteringModel & operator=(const G4eCoulombScatteringModel &right);
  G4eCoulombScatteringModel(const  G4eCoulombScatteringModel&);

protected:
 
  G4ParticleTable*          theParticleTable;
  G4ParticleChangeForGamma* fParticleChange;
  G4WentzelOKandVIxSection* wokvi;
  G4NistManager*            fNistManager;

  const std::vector<G4double>* pCuts;

  const G4MaterialCutsCouple* currentCouple;
  const G4Material*           currentMaterial;
  G4int                       currentMaterialIndex;

  G4double                  cosThetaMin;
  G4double                  cosThetaMax;
  G4double                  cosTetMinNuc;
  G4double                  cosTetMaxNuc;
  G4double                  recoilThreshold;
  G4double                  elecRatio;
  G4double                  mass;

  // projectile
  const G4ParticleDefinition* particle;
  const G4ParticleDefinition* theProton;

  G4double                  lowEnergyThreshold;

private:

  G4bool                    isInitialised;             
};

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

inline
void G4eCoulombScatteringModel::DefineMaterial(const G4MaterialCutsCouple* cup) 
{ 
  if(cup != currentCouple) {
    currentCouple = cup;
    currentMaterial = cup->GetMaterial();
    currentMaterialIndex = currentCouple->GetIndex(); 
  }
}

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

inline 
void G4eCoulombScatteringModel::SetupParticle(const G4ParticleDefinition* p)
{
  // Initialise mass and charge
  if(p != particle) {
    particle = p;
    mass = particle->GetPDGMass();
    wokvi->SetupParticle(p);
  }
}

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

inline void G4eCoulombScatteringModel::SetLowEnergyThreshold(G4double val)
{
  lowEnergyThreshold = val;
}

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

inline void G4eCoulombScatteringModel::SetRecoilThreshold(G4double eth)
{
  recoilThreshold = eth;
}

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

#endif