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//	G4ScreeningMottCrossSection.hh
//-------------------------------------------------------------------
//
// GEANT4 Class header file
//
// File name:    G4ScreeningMottCrossSection
//
// Author:      Cristina Consolandi
//
// Creation date: 20.10.2011 
//
// Class Description:
//      Computation of electron Coulomb Scattering Cross Section. 
// 	Suitable for high energy electrons and light target materials.
//
// Reference:
//     M.J. Boschini et al.
//    "Non Ionizing Energy Loss induced by Electrons in the Space Environment"
//     Proc. of the 13th International Conference on Particle Physics and Advanced Technology 
//     (13th ICPPAT, Como 3-7/10/2011), World Scientific (Singapore).
// 
// 
//       1) Mott Differential Cross Section Approximation:  
//       W. A. McKinley and H. Fashbach, Phys. Rev. 74, (1948) 1759.
//       2) Screening coefficient: 
//       vomn G. Moliere, Z. Naturforsh A2 (1947), 133-145; A3 (1948), 78.
//       3) Nuclear Form Factor: 
//       A.V. Butkevich et al. Nucl. Instr. and Meth. in Phys. Res. A 488 (2002), 282-294.
//       
// ----------------------------------------------------------------------------------------

//
#ifndef G4ScreeningMottCrossSection_h
#define G4ScreeningMottCrossSection_h 1

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

#include "globals.hh"
#include "G4Material.hh"
#include "G4Element.hh"
#include "G4ElementVector.hh"
#include "G4NistManager.hh"
#include "G4ThreeVector.hh"
#include "G4Pow.hh"
#include "G4LossTableManager.hh"

class G4ParticleDefinition;

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

class G4ScreeningMottCrossSection
{

public:

  	G4ScreeningMottCrossSection();

  	virtual ~G4ScreeningMottCrossSection();

   	void Initialise(const G4ParticleDefinition*, G4double cosThetaLim);

	G4double GetScreeningAngle();
	void SetScreeningCoefficient();


               
  	inline void SetupParticle(const G4ParticleDefinition*);
 	void SetupKinematic(G4double kinEnergy ,G4double Z);

        G4double NuclearCrossSection();
        G4ThreeVector GetNewDirection();

	inline G4double GetMom2CM()const;
	inline G4double GetMom2Lab()const;
	inline G4double GetTrec() const;
        inline G4double GetScreeningCoefficient() const;
        inline G4double GetTotalCross() const;

        G4double McFcorrection(G4double);
        G4double FormFactor2ExpHof(G4double);
        G4double GetScatteringAngle();
        G4double AngleDistribution(G4double);


private:

 	G4ScreeningMottCrossSection & operator=(const  G4ScreeningMottCrossSection &right);
  	G4ScreeningMottCrossSection(const  G4ScreeningMottCrossSection&);


  	G4NistManager*  fNistManager;		

	G4double 		TotalCross;

	//cost - min - max 
        G4double                cosThetaMin;// def 1.0
        G4double                cosThetaMax;// def -1.0

	G4double      		cosTetMinNuc;
        G4double		cosTetMaxNuc;


	//energy cut
  	G4double                ecut;	    
   	G4double                etag;	    

	// projectile........................
 	const G4ParticleDefinition* particle;

 	G4double                spin;	   
  	G4double                mass;	   

	//lab of incedent particle 
        G4double                tkinLab;
        G4double                momLab2;
        G4double                invbetaLab2;

	//relative system with nucleus
	G4double 		mu_rel;
 	G4double                tkin;	   
  	G4double                mom2;	   
  	G4double                invbeta2;	   
	G4double		beta;
	G4double		gamma;


  	// target nucleus
  	G4double                targetZ;    
	G4double 		targetA;
  	G4double                targetMass; 
	G4double 		Trec;
 	G4double 		As; 

	//constants
	G4double                 alpha;
  	G4double                 htc2;
        G4double                 e2;

};


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

inline void G4ScreeningMottCrossSection::SetupParticle(const G4ParticleDefinition* p)
{
  	particle = p;
  	mass = particle->GetPDGMass();
  	spin = particle->GetPDGSpin();
  		if(0.0 != spin) { spin = 0.5; }
  	tkin = 0.0;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....


inline G4double G4ScreeningMottCrossSection::GetMom2CM() const
{
	return mom2;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....


inline G4double G4ScreeningMottCrossSection::GetMom2Lab() const
{
        return momLab2;
}


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

inline G4double G4ScreeningMottCrossSection::GetTrec() const
{
        return Trec;
}

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

inline G4double G4ScreeningMottCrossSection::GetScreeningCoefficient() const
{
	return As;
}


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

inline G4double G4ScreeningMottCrossSection::GetTotalCross() const
{
	return TotalCross;
}

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

#endif