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// $Id$
//
// Author: Luciano Pandola
//
// History:
// -----------
// 29 Oct 2008   L. Pandola   1st implementation. Migration from EM process 
//                            to EM model
//
// -------------------------------------------------------------------
//
// Class description:
// Low Energy Electromagnetic Physics, Positron Annihilation 
// with Penelope Model
// -------------------------------------------------------------------

#ifndef G4PENELOPEANNIHILATIONMODEL_HH
#define G4PENELOPEANNIHILATIONMODEL_HH 1

#include "globals.hh"
#include "G4VEmModel.hh"
#include "G4DataVector.hh"
#include "G4ParticleChangeForGamma.hh"

class G4ParticleDefinition;
class G4DynamicParticle;
class G4MaterialCutsCouple;
class G4Material;

class G4PenelopeAnnihilationModel : public G4VEmModel 
{
public:
  
  G4PenelopeAnnihilationModel(const G4ParticleDefinition* p=0,
			 const G4String& processName ="PenAnnih");
  
  virtual ~G4PenelopeAnnihilationModel();

  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);

  void SetVerbosityLevel(G4int lev){verboseLevel = lev;};
  G4int GetVerbosityLevel(){return verboseLevel;};

protected:
  G4ParticleChangeForGamma* fParticleChange;

private:
  G4double ComputeCrossSectionPerElectron(G4double energy);

  G4PenelopeAnnihilationModel & operator=(const G4PenelopeAnnihilationModel &right);
  G4PenelopeAnnihilationModel(const G4PenelopeAnnihilationModel&);

  G4int verboseLevel;
  G4bool isInitialised;

  G4double fIntrinsicLowEnergyLimit;
  G4double fIntrinsicHighEnergyLimit;

  //Stored here so it is not recalculated every time
  G4double fPielr2;
};

#endif