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// $Id: G4EnergyLossForExtrapolator.hh,v 1.12 2008/11/13 14:14:07 vnivanch Exp $
// GEANT4 tag $Name: geant4-09-03-cand-01 $
//
//---------------------------------------------------------------------------
//
// ClassName:    G4EnergyLossForExtrapolator
//  
// Description:  This class provide calculation of energy loss, fluctuation, 
//               and msc angle
//
// Author:       09.12.04 V.Ivanchenko 
//
// Modification: 
// 08-04-05 Rename Propogator -> Extrapolator
// 16-03-06 Add muon tables
// 21-03-06 Add verbosity defined in the constructor and Initialisation
//          start only when first public method is called (V.Ivanchenko)
// 03-05-06 Remove unused pointer G4Material* from number of methods (VI)
// 28-07-07 Add maxEnergyTransfer for computation of energy loss (VI)
//
//----------------------------------------------------------------------------
//

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#ifndef G4EnergyLossForExtrapolator_h
#define G4EnergyLossForExtrapolator_h 1


#include "globals.hh"
#include "G4PhysicsTable.hh"
#include <vector>

class G4ParticleDefinition;
class G4Material;
class G4MaterialCutsCouple;
class G4ProductionCuts;

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class G4EnergyLossForExtrapolator 
{
public:
  G4EnergyLossForExtrapolator(G4int verb = 1);

  ~G4EnergyLossForExtrapolator();

  G4double ComputeDEDX(G4double kinEnergy, const G4ParticleDefinition*);

  G4double ComputeRange(G4double kinEnergy, const G4ParticleDefinition*);

  G4double ComputeEnergy(G4double range, const G4ParticleDefinition*);

  G4double EnergyAfterStep(G4double kinEnergy, G4double step, 
			   const G4Material*, const G4ParticleDefinition*);

  G4double EnergyBeforeStep(G4double kinEnergy, G4double step, 
	        	    const G4Material*, const G4ParticleDefinition*);

  G4double TrueStepLength(G4double kinEnergy, G4double step,
			  const G4Material*, const G4ParticleDefinition* part);

  inline G4double EnergyAfterStep(G4double kinEnergy, G4double step, 
				  const G4Material*, const G4String& particleName);

  inline G4double EnergyBeforeStep(G4double kinEnergy, G4double step, 
				   const G4Material*, const G4String& particleName);

  inline G4double AverageScatteringAngle(G4double kinEnergy, G4double step, 
					 const G4Material*, 
					 const G4ParticleDefinition* part);

  inline G4double AverageScatteringAngle(G4double kinEnergy, G4double step, 
					 const G4Material*, 
					 const G4String& particleName);

  inline G4double ComputeTrueStep(const G4Material*, const G4ParticleDefinition* part, 
				  G4double kinEnergy, G4double stepLength);

  inline G4double EnergyDispersion(G4double kinEnergy, G4double step, 
				   const G4Material*, const G4ParticleDefinition*);

  inline G4double EnergyDispersion(G4double kinEnergy, G4double step, 
				   const G4Material*, const G4String& particleName);

  inline void SetVerbose(G4int val);

  inline void SetMinKinEnergy(G4double);

  inline void SetMaxKinEnergy(G4double);

  inline void SetMaxEnergyTransfer(G4double);
   
private:

  void Initialisation();

  G4bool SetupKinematics(const G4ParticleDefinition*, const G4Material*, 
			 G4double kinEnergy);

  G4PhysicsTable* PrepareTable();

  const G4ParticleDefinition* FindParticle(const G4String& name);

  void ComputeElectronDEDX(const G4ParticleDefinition* part, G4PhysicsTable* table); 

  void ComputeMuonDEDX(const G4ParticleDefinition* part, G4PhysicsTable* table); 

  void ComputeProtonDEDX(const G4ParticleDefinition* part, G4PhysicsTable* table); 

  void ComputeTrasportXS(const G4ParticleDefinition* part, G4PhysicsTable* table);

  inline G4double ComputeValue(G4double x, const G4PhysicsTable* table);

  // hide assignment operator
  G4EnergyLossForExtrapolator & operator=(const G4EnergyLossForExtrapolator &right);
  G4EnergyLossForExtrapolator(const G4EnergyLossForExtrapolator&);

  const G4ParticleDefinition* currentParticle;
  const G4ParticleDefinition* electron;
  const G4ParticleDefinition* positron;
  const G4ParticleDefinition* muonPlus;
  const G4ParticleDefinition* muonMinus;
  const G4ParticleDefinition* proton;

  G4ProductionCuts*        cuts;
  std::vector<const G4MaterialCutsCouple*> couples;

  G4String currentParticleName;

  G4PhysicsTable*          dedxElectron;
  G4PhysicsTable*          dedxPositron;
  G4PhysicsTable*          dedxMuon;
  G4PhysicsTable*          dedxProton;
  G4PhysicsTable*          rangeElectron;
  G4PhysicsTable*          rangePositron;
  G4PhysicsTable*          rangeMuon;
  G4PhysicsTable*          rangeProton;
  G4PhysicsTable*          invRangeElectron;
  G4PhysicsTable*          invRangePositron;
  G4PhysicsTable*          invRangeMuon;
  G4PhysicsTable*          invRangeProton;
  G4PhysicsTable*          mscElectron;

  const G4Material* currentMaterial;
  G4int       index;
  G4double    electronDensity;
  G4double    radLength;
  G4double    mass;
  G4double    charge2;
  G4double    kineticEnergy;
  G4double    gam;
  G4double    bg2;
  G4double    beta2;
  G4double    tmax;

  G4double    linLossLimit;
  G4double    emin;
  G4double    emax;
  G4double    maxEnergyTransfer;

  G4int       nbins;
  G4int       nmat;
  G4int       verbose;
  G4bool      isInitialised;
};

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inline G4double G4EnergyLossForExtrapolator::EnergyAfterStep(G4double kinEnergy, 
							     G4double step, 
							     const G4Material* mat, 
							     const G4String& name)
{
  return EnergyAfterStep(kinEnergy,step,mat,FindParticle(name));
}

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

inline G4double G4EnergyLossForExtrapolator::EnergyBeforeStep(G4double kinEnergy, 
							      G4double step, 
							      const G4Material* mat, 
							      const G4String& name)
{
  return EnergyBeforeStep(kinEnergy,step,mat,FindParticle(name));
}

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inline G4double G4EnergyLossForExtrapolator::AverageScatteringAngle(G4double kinEnergy, 
								    G4double step, 
								    const G4Material* mat, 
								    const G4String& name)
{
  return AverageScatteringAngle(kinEnergy,step,mat,FindParticle(name));
}

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

inline G4double 
G4EnergyLossForExtrapolator::EnergyDispersion(G4double kinEnergy, 
					      G4double step, 
					      const G4Material* mat, 
					      const G4String& name)
{
  return EnergyDispersion(kinEnergy,step,mat,FindParticle(name));
}

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inline G4double 
G4EnergyLossForExtrapolator::AverageScatteringAngle(G4double kinEnergy, 
						    G4double stepLength, 
						    const G4Material* mat, 
						    const G4ParticleDefinition* part)
{
  G4double theta = 0.0;
  if(SetupKinematics(part, mat, kinEnergy)) {
    G4double t = stepLength/radLength;
    G4double y = std::max(0.001, t); 
    theta = 19.23*MeV*std::sqrt(charge2*t)*(1.0 + 0.038*std::log(y))/(beta2*gam*mass);
  }
  return theta;
}

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

inline G4double 
G4EnergyLossForExtrapolator::ComputeTrueStep(const G4Material* mat, 
					     const G4ParticleDefinition* part,
					     G4double kinEnergy, 
					     G4double stepLength)
{
  G4double theta = AverageScatteringAngle(kinEnergy,stepLength,mat,part);
  return stepLength*std::sqrt(1.0 + 0.625*theta*theta);
} 

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
  
inline 
G4double G4EnergyLossForExtrapolator::EnergyDispersion(G4double kinEnergy, 
						       G4double stepLength, 
						       const G4Material* mat, 
						       const G4ParticleDefinition* part)
{
  G4double sig2 = 0.0;
  if(SetupKinematics(part, mat, kinEnergy)) {
    G4double step = ComputeTrueStep(mat,part,kinEnergy,stepLength);
    sig2 = (1.0/beta2 - 0.5)*twopi_mc2_rcl2*tmax*step*electronDensity*charge2;
  }
  return sig2;
}

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

inline G4double G4EnergyLossForExtrapolator::ComputeValue(G4double x, 
							  const G4PhysicsTable* table)
{
  G4double res = 0.0;
  G4bool b;
  if(table) res = ((*table)[index])->GetValue(x, b);
  return res;
}

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

inline void G4EnergyLossForExtrapolator::SetVerbose(G4int val) 
{
  verbose = val;
}

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

inline void G4EnergyLossForExtrapolator::SetMinKinEnergy(G4double val)
{
  emin = val;
}

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

inline void G4EnergyLossForExtrapolator::SetMaxKinEnergy(G4double val)
{
  emax = val;
}

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inline void G4EnergyLossForExtrapolator::SetMaxEnergyTransfer(G4double val)
{
  maxEnergyTransfer = val;
}

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

#endif

