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// $Id$
//
// -------------------------------------------------------------------
//
// GEANT4 Class header file
//
//
// File name:     G4ionEffectiveCharge
//
// Author:        Vladimir Ivanchenko
//
// Creation date: 03.07.2004
//
// Modifications:
//
//
// Class Description:
//
// This class manages the simulation of effective charge of ions 
// in the assumption of equilibrium between ion shelss and media.
// J.F.Ziegler and J.M.Manoyan, The stopping of ions in compaunds,
// Nucl. Inst. & Meth. in Phys. Res. B35 (1988) 215-228.
//

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

#ifndef G4ionEffectiveCharge_h
#define G4ionEffectiveCharge_h 1

#include "globals.hh"
#include "G4ParticleDefinition.hh"

class G4Material;
class G4NistManager;

class G4ionEffectiveCharge 
{

public:

  G4ionEffectiveCharge();

  virtual ~G4ionEffectiveCharge();

  G4double EffectiveChargeSquareRatio(
                           const G4ParticleDefinition* p,
                           const G4Material* material,
			         G4double kineticEnergy);

  G4double EffectiveCharge(const G4ParticleDefinition* p,
                           const G4Material* material,
			         G4double kineticEnergy);

private:

  // hide assignment operator
  G4ionEffectiveCharge & operator=(const G4ionEffectiveCharge &right);
  G4ionEffectiveCharge(const G4ionEffectiveCharge&);

  G4NistManager*              nist;

  const G4ParticleDefinition* lastPart;
  const G4Material*           lastMat;
  G4double                    lastKinEnergy;

  G4double                    chargeCorrection;
  G4double                    effCharge;

  G4double                    energyHighLimit;
  G4double                    energyLowLimit;
  G4double                    energyBohr;
  G4double                    massFactor;
  G4double                    minCharge;
};

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

inline G4double G4ionEffectiveCharge::EffectiveChargeSquareRatio(
                           const G4ParticleDefinition* p,
                           const G4Material* material,
			         G4double kineticEnergy)
{
  G4double charge = effCharge;
  if( kineticEnergy != lastKinEnergy || material != lastMat || p != lastPart) {
    charge = EffectiveCharge(p,material,kineticEnergy);
  }
  charge *= chargeCorrection/CLHEP::eplus;

  return charge*charge;
}

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#endif