G4HeatedKleinNishinaCompton Class Reference

#include <G4HeatedKleinNishinaCompton.hh>

Inheritance diagram for G4HeatedKleinNishinaCompton:

Public Member Functions
	G4HeatedKleinNishinaCompton (const G4ParticleDefinition *p=0, const G4String &nam="Heated-Klein-Nishina")
virtual	~G4HeatedKleinNishinaCompton ()
virtual void	Initialise (const G4ParticleDefinition *, const G4DataVector &)
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)
void	SetElectronTemperature (G4double t)
G4double	GetElectronTemperature ()
Public Member Functions inherited from G4VEmModel
	G4VEmModel (const G4String &nam)
virtual	~G4VEmModel ()
virtual void	InitialiseLocal (const G4ParticleDefinition *, G4VEmModel *masterModel)
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
G4double	fTemperature
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 59 of file G4HeatedKleinNishinaCompton.hh.

Constructor & Destructor Documentation

G4HeatedKleinNishinaCompton::G4HeatedKleinNishinaCompton	(	const G4ParticleDefinition *	p = 0,
		const G4String &	nam = "Heated-Klein-Nishina"
	)

Definition at line 66 of file G4HeatedKleinNishinaCompton.cc.

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

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

G4HeatedKleinNishinaCompton::~G4HeatedKleinNishinaCompton ( )

virtual

Definition at line 79 of file G4HeatedKleinNishinaCompton.cc.

{}

Member Function Documentation

G4double G4HeatedKleinNishinaCompton::ComputeCrossSectionPerAtom ( const G4ParticleDefinition *  , G4double  kinEnergy, G4double  Z, G4double  A, G4double  cut, G4double  emax  )

virtual

Reimplemented from G4VEmModel.

Definition at line 94 of file G4HeatedKleinNishinaCompton.cc.

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

{
  G4double xSection = 0.0 ;
  if ( Z < 0.9999 )                 return xSection;
  if ( GammaEnergy < 0.01*keV      ) return xSection;
  //  if ( GammaEnergy > (100.*GeV/Z) ) return xSection;

  static const G4double a = 20.0 , b = 230.0 , c = 440.0;
  
  static const G4double
    d1= 2.7965e-1*barn, d2=-1.8300e-1*barn, d3= 6.7527   *barn, d4=-1.9798e+1*barn,
    e1= 1.9756e-5*barn, e2=-1.0205e-2*barn, e3=-7.3913e-2*barn, e4= 2.7079e-2*barn,
    f1=-3.9178e-7*barn, f2= 6.8241e-5*barn, f3= 6.0480e-5*barn, f4= 3.0274e-4*barn;
     
  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*std::log(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*log(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*log(Z);
    G4double    y = log(GammaEnergy/T0);
    xSection *= exp(-y*(c1+c2*y));          
  }
  //  G4cout << "e= " << GammaEnergy << " Z= " << Z << " cross= " << xSection << G4endl;
  return xSection;
}

G4double G4HeatedKleinNishinaCompton::GetElectronTemperature ( )

inline

Definition at line 86 of file G4HeatedKleinNishinaCompton.hh.

{return fTemperature;};

void G4HeatedKleinNishinaCompton::Initialise ( const G4ParticleDefinition *  , const G4DataVector &    )

virtual

Implements G4VEmModel.

Definition at line 84 of file G4HeatedKleinNishinaCompton.cc.

References fParticleChange, and G4VEmModel::GetParticleChangeForGamma().

{
  if(!fParticleChange) fParticleChange = GetParticleChangeForGamma();
}

void G4HeatedKleinNishinaCompton::SampleSecondaries ( std::vector< G4DynamicParticle * > *  fvect, const G4MaterialCutsCouple *  , const G4DynamicParticle *  aDynamicGamma, G4double  tmin, G4double  maxEnergy  )

virtual

Implements G4VEmModel.

Definition at line 142 of file G4HeatedKleinNishinaCompton.cc.

References CLHEP::HepLorentzVector::boost(), CLHEP::HepLorentzVector::boostVector(), DBL_MIN, python.hepunit::electron_mass_c2, fParticleChange, fStopAndKill, fTemperature, G4RandomDirection(), G4UniformRand, G4DynamicParticle::Get4Momentum(), G4VParticleChange::GetLocalEnergyDeposit(), lowestGammaEnergy, CLHEP::Hep3Vector::mag(), G4VParticleChange::ProposeLocalEnergyDeposit(), G4ParticleChangeForGamma::ProposeMomentumDirection(), G4VParticleChange::ProposeTrackStatus(), CLHEP::Hep3Vector::rotateUz(), G4ParticleChangeForGamma::SetProposedKineticEnergy(), G4INCL::DeJongSpin::shoot(), CLHEP::HepLorentzVector::t(), theElectron, python.hepunit::twopi, CLHEP::Hep3Vector::unit(), and CLHEP::HepLorentzVector::vect().

{
  // 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.

  // We start to prepare a heated electron from Maxwell distribution. 
  // Then we try to boost to the electron rest frame and make scattering.
  // The final step is to recover new gamma 4momentum in the lab frame

  G4double eMomentumC2   = G4RandGamma::shoot(1.5,1.);
  eMomentumC2          *= 2*electron_mass_c2*fTemperature; // electron (pc)^2
  G4ThreeVector eMomDir = G4RandomDirection();
  eMomDir              *= std::sqrt(eMomentumC2);
  G4double eEnergy      = std::sqrt(eMomentumC2+electron_mass_c2*electron_mass_c2);
  G4LorentzVector electron4v = G4LorentzVector(eMomDir,eEnergy);
  G4ThreeVector bst = electron4v.boostVector();

  G4LorentzVector gamma4v = aDynamicGamma->Get4Momentum();
  gamma4v.boost(-bst);

  G4ThreeVector gammaMomV = gamma4v.vect();
  G4double  gamEnergy0    = gammaMomV.mag();
 
 
  // G4double gamEnergy0 = aDynamicGamma->GetKineticEnergy();
  G4double E0_m = gamEnergy0 / electron_mass_c2 ;

  // G4ThreeVector gamDirection0 = /aDynamicGamma->GetMomentumDirection();

  G4ThreeVector gamDirection0 = gammaMomV/gamEnergy0;
  
  // sample the energy rate of the scattered gamma in the electron rest frame
  //

  G4double epsilon, epsilonsq, onecost, sint2, greject ;

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

  do 
  {
    if ( alpha1/(alpha1+alpha2) > G4UniformRand() ) 
    {
      epsilon   = exp(-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)
  //

  G4double cosTeta = 1. - onecost; 
  G4double sinTeta = sqrt (sint2);
  G4double Phi     = twopi * G4UniformRand();
  G4double dirx    = sinTeta*cos(Phi), diry = sinTeta*sin(Phi), dirz = cosTeta;

  //
  // update G4VParticleChange for the scattered gamma
  //
   
  G4ThreeVector gamDirection1 ( dirx,diry,dirz );
  gamDirection1.rotateUz(gamDirection0);
  G4double gamEnergy1  = epsilon*gamEnergy0;
  gamDirection1       *= gamEnergy1;

  G4LorentzVector gamma4vfinal = G4LorentzVector(gamDirection1,gamEnergy1);

  
  // kinematic of the scattered electron
  //

  G4double eKinEnergy = gamEnergy0 - gamEnergy1;
  G4ThreeVector eDirection = gamEnergy0*gamDirection0 - gamEnergy1*gamDirection1;
  eDirection = eDirection.unit();
  G4double eFinalMom = std::sqrt(eKinEnergy*(eKinEnergy+2*electron_mass_c2));
  eDirection *= eFinalMom;
  G4LorentzVector e4vfinal = G4LorentzVector(eDirection,gamEnergy1+electron_mass_c2);
  
  gamma4vfinal.boost(bst);
  e4vfinal.boost(bst);

  gamDirection1 = gamma4vfinal.vect();
  gamEnergy1 = gamDirection1.mag(); 
  gamDirection1 /= gamEnergy1;




  fParticleChange->SetProposedKineticEnergy(gamEnergy1);

  if( gamEnergy1 > lowestGammaEnergy ) 
  {
    gamDirection1 /= gamEnergy1;
    fParticleChange->ProposeMomentumDirection(gamDirection1);
  } 
  else 
  { 
    fParticleChange->ProposeTrackStatus(fStopAndKill);
    gamEnergy1 += fParticleChange->GetLocalEnergyDeposit();
    fParticleChange->ProposeLocalEnergyDeposit(gamEnergy1);
  }

  eKinEnergy = e4vfinal.t()-electron_mass_c2;

  if( eKinEnergy > DBL_MIN ) 
  {
    // create G4DynamicParticle object for the electron.
    eDirection = e4vfinal.vect();
    G4double eFinMomMag = eDirection.mag();
    eDirection /= eFinMomMag;
    G4DynamicParticle* dp = new G4DynamicParticle(theElectron,eDirection,eKinEnergy);
    fvect->push_back(dp);
  }
}

void G4HeatedKleinNishinaCompton::SetElectronTemperature ( G4double  t )

inline

Definition at line 85 of file G4HeatedKleinNishinaCompton.hh.

References fTemperature.

{fTemperature=t;};

Field Documentation

G4ParticleChangeForGamma* G4HeatedKleinNishinaCompton::fParticleChange

protected

Definition at line 92 of file G4HeatedKleinNishinaCompton.hh.

Referenced by G4HeatedKleinNishinaCompton(), Initialise(), and SampleSecondaries().

G4double G4HeatedKleinNishinaCompton::fTemperature

protected

Definition at line 94 of file G4HeatedKleinNishinaCompton.hh.

Referenced by G4HeatedKleinNishinaCompton(), SampleSecondaries(), and SetElectronTemperature().

G4double G4HeatedKleinNishinaCompton::lowestGammaEnergy

protected

Definition at line 93 of file G4HeatedKleinNishinaCompton.hh.

Referenced by G4HeatedKleinNishinaCompton(), and SampleSecondaries().

G4ParticleDefinition* G4HeatedKleinNishinaCompton::theElectron

protected

Definition at line 91 of file G4HeatedKleinNishinaCompton.hh.

Referenced by G4HeatedKleinNishinaCompton(), and SampleSecondaries().

G4ParticleDefinition* G4HeatedKleinNishinaCompton::theGamma

protected

Definition at line 86 of file G4HeatedKleinNishinaCompton.hh.

Referenced by G4HeatedKleinNishinaCompton().

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

• G4HeatedKleinNishinaCompton.hh
• G4HeatedKleinNishinaCompton.cc