G4KleinNishinaCompton Class Reference

#include <G4KleinNishinaCompton.hh>

Inheritance diagram for G4KleinNishinaCompton:

Public Member Functions
	G4KleinNishinaCompton (const G4ParticleDefinition *p=0, const G4String &nam="Klein-Nishina")
virtual	~G4KleinNishinaCompton ()
virtual void	Initialise (const G4ParticleDefinition *, const G4DataVector &)
virtual void	InitialiseLocal (const G4ParticleDefinition *, G4VEmModel *masterModel)
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)
Public Member Functions inherited from G4VEmModel
	G4VEmModel (const G4String &nam)
virtual	~G4VEmModel ()
virtual void	InitialiseForMaterial (const G4ParticleDefinition *, const G4Material *)
virtual void	InitialiseForElement (const G4ParticleDefinition *, G4int Z)
virtual G4double	ComputeDEDXPerVolume (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=DBL_MAX)
virtual G4double	CrossSectionPerVolume (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
virtual G4double	ChargeSquareRatio (const G4Track &)
virtual G4double	GetChargeSquareRatio (const G4ParticleDefinition *, const G4Material *, G4double kineticEnergy)
virtual G4double	GetParticleCharge (const G4ParticleDefinition *, const G4Material *, G4double kineticEnergy)
virtual void	StartTracking (G4Track *)
virtual void	CorrectionsAlongStep (const G4MaterialCutsCouple *, const G4DynamicParticle *, G4double &eloss, G4double &niel, G4double length)
virtual G4double	Value (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy)
virtual G4double	MinPrimaryEnergy (const G4Material *, const G4ParticleDefinition *, G4double cut=0.0)
virtual G4double	MinEnergyCut (const G4ParticleDefinition *, const G4MaterialCutsCouple *)
virtual void	SetupForMaterial (const G4ParticleDefinition *, const G4Material *, G4double kineticEnergy)
virtual void	DefineForRegion (const G4Region *)
void	InitialiseElementSelectors (const G4ParticleDefinition *, const G4DataVector &)
std::vector < G4EmElementSelector * > *	GetElementSelectors ()
void	SetElementSelectors (std::vector< G4EmElementSelector * > *)
G4double	ComputeDEDX (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=DBL_MAX)
G4double	CrossSection (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
G4double	ComputeMeanFreePath (const G4ParticleDefinition *, G4double kineticEnergy, const G4Material *, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *, const G4Element *, G4double kinEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
G4int	SelectIsotopeNumber (const G4Element *)
const G4Element *	SelectRandomAtom (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
const G4Element *	SelectRandomAtom (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
G4int	SelectRandomAtomNumber (const G4Material *)
void	SetParticleChange (G4VParticleChange *, G4VEmFluctuationModel *f=0)
void	SetCrossSectionTable (G4PhysicsTable *, G4bool isLocal)
G4ElementData *	GetElementData ()
G4PhysicsTable *	GetCrossSectionTable ()
G4VEmFluctuationModel *	GetModelOfFluctuations ()
G4VEmAngularDistribution *	GetAngularDistribution ()
void	SetAngularDistribution (G4VEmAngularDistribution *)
G4double	HighEnergyLimit () const
G4double	LowEnergyLimit () const
G4double	HighEnergyActivationLimit () const
G4double	LowEnergyActivationLimit () const
G4double	PolarAngleLimit () const
G4double	SecondaryThreshold () const
G4bool	LPMFlag () const
G4bool	DeexcitationFlag () const
G4bool	ForceBuildTableFlag () const
G4bool	UseAngularGeneratorFlag () const
void	SetAngularGeneratorFlag (G4bool)
void	SetHighEnergyLimit (G4double)
void	SetLowEnergyLimit (G4double)
void	SetActivationHighEnergyLimit (G4double)
void	SetActivationLowEnergyLimit (G4double)
G4bool	IsActive (G4double kinEnergy)
void	SetPolarAngleLimit (G4double)
void	SetSecondaryThreshold (G4double)
void	SetLPMFlag (G4bool val)
void	SetDeexcitationFlag (G4bool val)
void	SetForceBuildTable (G4bool val)
void	SetMasterThread (G4bool val)
G4bool	IsMaster () const
G4double	MaxSecondaryKinEnergy (const G4DynamicParticle *dynParticle)
const G4String &	GetName () const
void	SetCurrentCouple (const G4MaterialCutsCouple *)
const G4Element *	GetCurrentElement () const

Protected Attributes
G4ParticleDefinition *	theGamma
G4ParticleDefinition *	theElectron
G4ParticleChangeForGamma *	fParticleChange
G4double	lowestGammaEnergy
Protected Attributes inherited from G4VEmModel
G4ElementData *	fElementData
G4VParticleChange *	pParticleChange
G4PhysicsTable *	xSectionTable
const std::vector< G4double > *	theDensityFactor
const std::vector< G4int > *	theDensityIdx
size_t	idxTable

Additional Inherited Members
Protected Member Functions inherited from G4VEmModel
G4ParticleChangeForLoss *	GetParticleChangeForLoss ()
G4ParticleChangeForGamma *	GetParticleChangeForGamma ()
virtual G4double	MaxSecondaryEnergy (const G4ParticleDefinition *, G4double kineticEnergy)
const G4MaterialCutsCouple *	CurrentCouple () const
void	SetCurrentElement (const G4Element *)

Detailed Description

Definition at line 58 of file G4KleinNishinaCompton.hh.

Constructor & Destructor Documentation

G4KleinNishinaCompton::G4KleinNishinaCompton	(	const G4ParticleDefinition *	p = 0,
		const G4String &	nam = "Klein-Nishina"
	)

Definition at line 70 of file G4KleinNishinaCompton.cc.

References G4Electron::Electron(), python.hepunit::eV, fParticleChange, G4Gamma::Gamma(), lowestGammaEnergy, theElectron, and theGamma.

  : G4VEmModel(nam)
{
  theGamma = G4Gamma::Gamma();
  theElectron = G4Electron::Electron();
  lowestGammaEnergy = 1.0*eV;
  fParticleChange = 0;
}

G4KleinNishinaCompton::~G4KleinNishinaCompton ( )

virtual

Definition at line 82 of file G4KleinNishinaCompton.cc.

{}

Member Function Documentation

G4double G4KleinNishinaCompton::ComputeCrossSectionPerAtom ( const G4ParticleDefinition *  , G4double  kinEnergy, G4double  Z, G4double  A, G4double  cut, G4double  emax  )

virtual

Reimplemented from G4VEmModel.

Reimplemented in G4PolarizedComptonModel.

Definition at line 104 of file G4KleinNishinaCompton.cc.

References test::a, test::b, test::c, plottest35::c1, python.hepunit::electron_mass_c2, G4Exp(), G4Log(), python.hepunit::keV, and G4INCL::Math::max().

Referenced by G4PolarizedComptonModel::ComputeCrossSectionPerAtom().

{
  G4double xSection = 0.0 ;
  if ( Z < 0.9999 )                 return xSection;
  if ( GammaEnergy < 0.1*keV      ) return xSection;
  //  if ( GammaEnergy > (100.*GeV/Z) ) return xSection;

  static const G4double a = 20.0 , b = 230.0 , c = 440.0;
       
  G4double p1Z = Z*(d1 + e1*Z + f1*Z*Z), p2Z = Z*(d2 + e2*Z + f2*Z*Z),
           p3Z = Z*(d3 + e3*Z + f3*Z*Z), p4Z = Z*(d4 + e4*Z + f4*Z*Z);

  G4double T0  = 15.0*keV; 
  if (Z < 1.5) T0 = 40.0*keV; 

  G4double X   = max(GammaEnergy, T0) / electron_mass_c2;
  xSection = p1Z*G4Log(1.+2.*X)/X
               + (p2Z + p3Z*X + p4Z*X*X)/(1. + a*X + b*X*X + c*X*X*X);
        
  //  modification for low energy. (special case for Hydrogen)
  if (GammaEnergy < T0) {
    G4double dT0 = 1.*keV;
    X = (T0+dT0) / electron_mass_c2 ;
    G4double sigma = p1Z*G4Log(1.+2*X)/X
                    + (p2Z + p3Z*X + p4Z*X*X)/(1. + a*X + b*X*X + c*X*X*X);
    G4double   c1 = -T0*(sigma-xSection)/(xSection*dT0);             
    G4double   c2 = 0.150; 
    if (Z > 1.5) c2 = 0.375-0.0556*G4Log(Z);
    G4double    y = G4Log(GammaEnergy/T0);
    xSection *= G4Exp(-y*(c1+c2*y));          
  }
  //  G4cout << "e= " << GammaEnergy << " Z= " << Z << " cross= " << xSection << G4endl;
  return xSection;
}

void G4KleinNishinaCompton::Initialise ( const G4ParticleDefinition *  p, const G4DataVector &  cuts  )

virtual

Implements G4VEmModel.

Definition at line 87 of file G4KleinNishinaCompton.cc.

References fParticleChange, G4VEmModel::GetParticleChangeForGamma(), G4VEmModel::InitialiseElementSelectors(), and G4VEmModel::IsMaster().

{
  if(IsMaster()) { InitialiseElementSelectors(p, cuts); }
  if(!fParticleChange) { fParticleChange = GetParticleChangeForGamma(); }
}

void G4KleinNishinaCompton::InitialiseLocal ( const G4ParticleDefinition *  , G4VEmModel *  masterModel  )

virtual

Reimplemented from G4VEmModel.

Definition at line 96 of file G4KleinNishinaCompton.cc.

References G4VEmModel::GetElementSelectors(), and G4VEmModel::SetElementSelectors().

{
  SetElementSelectors(masterModel->GetElementSelectors());
}

void G4KleinNishinaCompton::SampleSecondaries ( std::vector< G4DynamicParticle * > *  fvect, const G4MaterialCutsCouple *  , const G4DynamicParticle *  aDynamicGamma, G4double  tmin, G4double  maxEnergy  )

virtual

Implements G4VEmModel.

Reimplemented in G4PolarizedComptonModel, and MyKleinNishinaCompton.

Definition at line 145 of file G4KleinNishinaCompton.cc.

References DBL_MIN, python.hepunit::electron_mass_c2, fParticleChange, fStopAndKill, G4Exp(), G4Log(), G4UniformRand, G4DynamicParticle::GetKineticEnergy(), G4DynamicParticle::GetMomentumDirection(), lowestGammaEnergy, G4VParticleChange::ProposeLocalEnergyDeposit(), G4ParticleChangeForGamma::ProposeMomentumDirection(), G4VParticleChange::ProposeTrackStatus(), CLHEP::Hep3Vector::rotateUz(), G4ParticleChangeForGamma::SetProposedKineticEnergy(), theElectron, python.hepunit::twopi, and CLHEP::Hep3Vector::unit().

{
  // The scattered gamma energy is sampled according to Klein - Nishina formula.
  // The random number techniques of Butcher & Messel are used 
  // (Nuc Phys 20(1960),15).
  // Note : Effects due to binding of atomic electrons are negliged.
 
  G4double gamEnergy0 = aDynamicGamma->GetKineticEnergy();

  // extra protection
  if(gamEnergy0 < lowestGammaEnergy) {
    fParticleChange->ProposeTrackStatus(fStopAndKill);
    fParticleChange->ProposeLocalEnergyDeposit(gamEnergy0);
    fParticleChange->SetProposedKineticEnergy(0.0);
    return;
  }

  G4double E0_m = gamEnergy0 / electron_mass_c2 ;

  G4ThreeVector gamDirection0 = aDynamicGamma->GetMomentumDirection();

  //
  // sample the energy rate of the scattered gamma 
  //

  G4double epsilon, epsilonsq, onecost, sint2, greject ;

  G4double eps0       = 1./(1. + 2.*E0_m);
  G4double epsilon0sq = eps0*eps0;
  G4double alpha1     = - G4Log(eps0);
  G4double alpha2     = 0.5*(1.- epsilon0sq);

  do {
    if ( alpha1/(alpha1+alpha2) > G4UniformRand() ) {
      epsilon   = G4Exp(-alpha1*G4UniformRand());   // eps0**r
      epsilonsq = epsilon*epsilon; 

    } else {
      epsilonsq = epsilon0sq + (1.- epsilon0sq)*G4UniformRand();
      epsilon   = sqrt(epsilonsq);
    };

    onecost = (1.- epsilon)/(epsilon*E0_m);
    sint2   = onecost*(2.-onecost);
    greject = 1. - epsilon*sint2/(1.+ epsilonsq);

  } while (greject < G4UniformRand());
 
  //
  // scattered gamma angles. ( Z - axis along the parent gamma)
  //

  if(sint2 < 0.0) { sint2 = 0.0; }
  G4double cosTeta = 1. - onecost; 
  G4double sinTeta = sqrt (sint2);
  G4double Phi     = twopi * G4UniformRand();

  //
  // update G4VParticleChange for the scattered gamma
  //
   
  G4ThreeVector gamDirection1(sinTeta*cos(Phi), sinTeta*sin(Phi), cosTeta);
  gamDirection1.rotateUz(gamDirection0);
  G4double gamEnergy1 = epsilon*gamEnergy0;
  if(gamEnergy1 > lowestGammaEnergy) {
    fParticleChange->ProposeMomentumDirection(gamDirection1);
    fParticleChange->SetProposedKineticEnergy(gamEnergy1);
  } else { 
    fParticleChange->ProposeTrackStatus(fStopAndKill);
    fParticleChange->ProposeLocalEnergyDeposit(gamEnergy1);
    fParticleChange->SetProposedKineticEnergy(0.0);
  }

  //
  // kinematic of the scattered electron
  //

  G4double eKinEnergy = gamEnergy0 - gamEnergy1;

  if(eKinEnergy > DBL_MIN) {
    G4ThreeVector eDirection = gamEnergy0*gamDirection0 - gamEnergy1*gamDirection1;
    eDirection = eDirection.unit();

    // create G4DynamicParticle object for the electron.
    G4DynamicParticle* dp = new G4DynamicParticle(theElectron,eDirection,eKinEnergy);
    fvect->push_back(dp);
  }
}

Field Documentation

G4ParticleChangeForGamma* G4KleinNishinaCompton::fParticleChange

protected

Definition at line 91 of file G4KleinNishinaCompton.hh.

Referenced by G4KleinNishinaCompton(), Initialise(), MyKleinNishinaCompton::SampleSecondaries(), G4PolarizedComptonModel::SampleSecondaries(), and SampleSecondaries().

G4double G4KleinNishinaCompton::lowestGammaEnergy

protected

Definition at line 92 of file G4KleinNishinaCompton.hh.

Referenced by G4KleinNishinaCompton(), G4PolarizedComptonModel::SampleSecondaries(), and SampleSecondaries().

G4ParticleDefinition* G4KleinNishinaCompton::theElectron

protected

Definition at line 90 of file G4KleinNishinaCompton.hh.

Referenced by G4KleinNishinaCompton(), MyKleinNishinaCompton::SampleSecondaries(), G4PolarizedComptonModel::SampleSecondaries(), and SampleSecondaries().

G4ParticleDefinition* G4KleinNishinaCompton::theGamma

protected

Definition at line 89 of file G4KleinNishinaCompton.hh.

Referenced by G4KleinNishinaCompton().

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The documentation for this class was generated from the following files:

• G4KleinNishinaCompton.hh
• G4KleinNishinaCompton.cc