#include <G4MollerBhabhaModel.hh>

Inheritance diagram for G4MollerBhabhaModel:

Collaboration diagram for G4MollerBhabhaModel:

Public Member Functions
	G4MollerBhabhaModel (const G4ParticleDefinition *p=nullptr, const G4String &nam="MollerBhabha")

virtual	~G4MollerBhabhaModel ()

virtual void	Initialise (const G4ParticleDefinition *, const G4DataVector &) override

virtual G4double	ComputeCrossSectionPerElectron (const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy, G4double maxEnergy)

virtual G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *, G4double kineticEnergy, G4double Z, G4double A, G4double cutEnergy, G4double maxEnergy) override

virtual G4double	CrossSectionPerVolume (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy, G4double maxEnergy) override

virtual G4double	ComputeDEDXPerVolume (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy) override

virtual void	SampleSecondaries (std::vector< G4DynamicParticle * > , const G4MaterialCutsCouple , const G4DynamicParticle *, G4double tmin, G4double maxEnergy) override

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	GetPartialCrossSection (const G4Material , G4int level, const G4ParticleDefinition , G4double kineticEnergy)

virtual G4double	ComputeCrossSectionPerShell (const G4ParticleDefinition *, G4int Z, G4int shellIdx, G4double kinEnergy, 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 *)

virtual void	ModelDescription (std::ostream &outFile) const

void	InitialiseElementSelectors (const G4ParticleDefinition *, const G4DataVector &)

std::vector < G4EmElementSelector * > *	GetElementSelectors ()

void	SetElementSelectors (std::vector< G4EmElementSelector * > *)

virtual 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=nullptr)

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

const G4Isotope *	GetCurrentIsotope () const

G4bool	IsLocked () const

void	SetLocked (G4bool)

Protected Member Functions
virtual G4double	MaxSecondaryEnergy (const G4ParticleDefinition *, G4double kinEnergy) final

void	SetParticle (const G4ParticleDefinition *p)

Protected Member Functions inherited from G4VEmModel
G4ParticleChangeForLoss *	GetParticleChangeForLoss ()

G4ParticleChangeForGamma *	GetParticleChangeForGamma ()

const G4MaterialCutsCouple *	CurrentCouple () const

void	SetCurrentElement (const G4Element *)

Protected Attributes
const G4ParticleDefinition *	particle

G4ParticleDefinition *	theElectron

G4ParticleChangeForLoss *	fParticleChange

G4bool	isElectron

G4double	twoln10

G4double	lowLimit

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
Static Protected Attributes inherited from G4VEmModel
static const G4double	inveplus = 1.0/CLHEP::eplus

Detailed Description

Definition at line 63 of file G4MollerBhabhaModel.hh.

Constructor & Destructor Documentation

G4MollerBhabhaModel::G4MollerBhabhaModel	(	const G4ParticleDefinition *	p = `nullptr`,
		const G4String &	nam = `"MollerBhabha"`
	)

explicit

Definition at line 76 of file G4MollerBhabhaModel.cc.

   : G4VEmModel(nam),
     particle(nullptr),
     isElectron(true),
     twoln10(2.0*G4Log(10.0)),
     lowLimit(0.02*keV),
     isInitialised(false)
 {
   theElectron = G4Electron::Electron();
   if(p) { SetParticle(p); }
   fParticleChange = nullptr;
 }

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G4MollerBhabhaModel::~G4MollerBhabhaModel ( )

virtual

Definition at line 92 of file G4MollerBhabhaModel.cc.

93 {}

Member Function Documentation

G4double G4MollerBhabhaModel::ComputeCrossSectionPerAtom	(	const G4ParticleDefinition *	p,
		G4double	kineticEnergy,
		G4double	Z,
		G4double	A,
		G4double	cutEnergy,
		G4double	maxEnergy
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 178 of file G4MollerBhabhaModel.cc.

 {
   return Z*ComputeCrossSectionPerElectron(p,kineticEnergy,cutEnergy,maxEnergy);
 }

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G4double G4MollerBhabhaModel::ComputeCrossSectionPerElectron	(	const G4ParticleDefinition *	p,
		G4double	kineticEnergy,
		G4double	cutEnergy,
		G4double	maxEnergy
	)

virtual

Reimplemented in G4PolarizedMollerBhabhaModel.

Definition at line 124 of file G4MollerBhabhaModel.cc.

 {
   if(!particle) { SetParticle(p); }
 
   G4double cross = 0.0;
   G4double tmax = MaxSecondaryEnergy(p, kineticEnergy);
   tmax = std::min(maxEnergy, tmax);
   //G4cout << "E= " << kineticEnergy << " cut= " << cutEnergy 
   //         << " Emax= " << tmax << G4endl;
   if(cutEnergy < tmax) {
 
     G4double xmin  = cutEnergy/kineticEnergy;
     G4double xmax  = tmax/kineticEnergy;
     G4double tau   = kineticEnergy/electron_mass_c2;
     G4double gam   = tau + 1.0;
     G4double gamma2= gam*gam;
     G4double beta2 = tau*(tau + 2)/gamma2;
 
     //Moller (e-e-) scattering
     if (isElectron) {
 
       G4double gg = (2.0*gam - 1.0)/gamma2;
       cross = ((xmax - xmin)*(1.0 - gg + 1.0/(xmin*xmax)
                               + 1.0/((1.0-xmin)*(1.0 - xmax)))
             - gg*G4Log( xmax*(1.0 - xmin)/(xmin*(1.0 - xmax)) ) ) / beta2;
 
     //Bhabha (e+e-) scattering
     } else {
 
       G4double y   = 1.0/(1.0 + gam);
       G4double y2  = y*y;
       G4double y12 = 1.0 - 2.0*y;
       G4double b1  = 2.0 - y2;
       G4double b2  = y12*(3.0 + y2);
       G4double y122= y12*y12;
       G4double b4  = y122*y12;
       G4double b3  = b4 + y122;
 
       cross = (xmax - xmin)*(1.0/(beta2*xmin*xmax) + b2
             - 0.5*b3*(xmin + xmax)
             + b4*(xmin*xmin + xmin*xmax + xmax*xmax)/3.0)
             - b1*G4Log(xmax/xmin);
     }
 
     cross *= twopi_mc2_rcl2/kineticEnergy;
   }
   return cross;
 }

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G4double G4MollerBhabhaModel::ComputeDEDXPerVolume	(	const G4Material *	material,
		const G4ParticleDefinition *	p,
		G4double	kineticEnergy,
		G4double	cutEnergy
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 203 of file G4MollerBhabhaModel.cc.

 {
   if(nullptr == particle) { SetParticle(p); }
   // calculate the dE/dx due to the ionization by Seltzer-Berger formula
   // checl low-energy limit
   G4double electronDensity = material->GetElectronDensity();
   
   G4double Zeff  = material->GetIonisation()->GetZeffective();
   G4double th    = 0.25*sqrt(Zeff)*keV;
   G4double tkin = std::max(kineticEnergy, th);
  
   G4double tau   = tkin/electron_mass_c2;
   G4double gam   = tau + 1.0;
   G4double gamma2= gam*gam;
   G4double bg2   = tau*(tau + 2);
   G4double beta2 = bg2/gamma2;
 
   G4double eexc  = material->GetIonisation()->GetMeanExcitationEnergy();
   eexc          /= electron_mass_c2;
   G4double eexc2 = eexc*eexc; 
 
   G4double d = std::min(cut, MaxSecondaryEnergy(p, tkin))/electron_mass_c2;
   G4double dedx;
 
   // electron
   if (isElectron) {
 
     dedx = G4Log(2.0*(tau + 2.0)/eexc2) - 1.0 - beta2
          + G4Log((tau-d)*d) + tau/(tau-d)
          + (0.5*d*d + (2.0*tau + 1.)*G4Log(1. - d/tau))/gamma2;
    
   //positron
   } else {
 
     G4double d2 = d*d*0.5;
     G4double d3 = d2*d/1.5;
     G4double d4 = d3*d*0.75;
     G4double y  = 1.0/(1.0 + gam);
     dedx = G4Log(2.0*(tau + 2.0)/eexc2) + G4Log(tau*d)
          - beta2*(tau + 2.0*d - y*(3.0*d2 
          + y*(d - d3 + y*(d2 - tau*d3 + d4))))/tau;
   } 
 
   //density correction 
   G4double x = G4Log(bg2)/twoln10;
   dedx -= material->GetIonisation()->DensityCorrection(x); 
 
   // now you can compute the total ionization loss
   dedx *= twopi_mc2_rcl2*electronDensity/beta2;
   if (dedx < 0.0) { dedx = 0.0; }
  
   // lowenergy extrapolation
  
   if (kineticEnergy < th) {
     x = kineticEnergy/th;
     if(x > 0.25) { dedx /= sqrt(x); }
     else { dedx *= 1.4*sqrt(x)/(0.1 + x); }
   }
   return dedx;
 }

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G4double G4MollerBhabhaModel::CrossSectionPerVolume	(	const G4Material *	material,
		const G4ParticleDefinition *	p,
		G4double	kineticEnergy,
		G4double	cutEnergy,
		G4double	maxEnergy
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 190 of file G4MollerBhabhaModel.cc.

 {
   G4double eDensity = material->GetElectronDensity();
   return eDensity*ComputeCrossSectionPerElectron(p,kinEnergy,cutEnergy,maxEnergy);
 }

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void G4MollerBhabhaModel::Initialise	(	const G4ParticleDefinition *	p,
		const G4DataVector &
	)

overridevirtual

Implements G4VEmModel.

Definition at line 107 of file G4MollerBhabhaModel.cc.

 {
   if(!particle) { SetParticle(p); }
 
   if(isInitialised) { return; }
 
   isInitialised = true;
   fParticleChange = GetParticleChangeForLoss();
   if(UseAngularGeneratorFlag() && !GetAngularDistribution()) {
     SetAngularDistribution(new G4DeltaAngle());
   }
 }

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G4double G4MollerBhabhaModel::MaxSecondaryEnergy	(	const G4ParticleDefinition *	,
		G4double	kinEnergy
	)

finalprotectedvirtual

Reimplemented from G4VEmModel.

Definition at line 97 of file G4MollerBhabhaModel.cc.

 {
   G4double tmax = kinEnergy;
   if(isElectron) { tmax *= 0.5; }
   return tmax;
 }

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void G4MollerBhabhaModel::SampleSecondaries	(	std::vector< G4DynamicParticle * > *	vdp,
		const G4MaterialCutsCouple *	couple,
		const G4DynamicParticle *	dp,
		G4double	tmin,
		G4double	maxEnergy
	)

overridevirtual

Implements G4VEmModel.

Reimplemented in G4PolarizedMollerBhabhaModel.

Definition at line 271 of file G4MollerBhabhaModel.cc.

 {
   G4double kineticEnergy = dp->GetKineticEnergy();
   //G4cout << "G4MollerBhabhaModel::SampleSecondaries: E= " << kineticEnergy
   //       << " in " << couple->GetMaterial()->GetName() << G4endl;
   G4double tmax;
   G4double tmin = cutEnergy;  
   if(isElectron) { 
     tmax = 0.5*kineticEnergy; 
   } else {
     tmax = kineticEnergy; 
   }
   if(maxEnergy < tmax) { tmax = maxEnergy; }
   if(tmin >= tmax) { return; }
 
   G4double energy = kineticEnergy + electron_mass_c2;
   G4double xmin   = tmin/kineticEnergy;
   G4double xmax   = tmax/kineticEnergy;
   G4double gam    = energy/electron_mass_c2;
   G4double gamma2 = gam*gam;
   G4double beta2  = 1.0 - 1.0/gamma2;
   G4double x, z, grej;
   CLHEP::HepRandomEngine* rndmEngine = G4Random::getTheEngine();
   G4double rndm[2];
 
   //Moller (e-e-) scattering
   if (isElectron) {
 
     G4double gg = (2.0*gam - 1.0)/gamma2;
     G4double y = 1.0 - xmax;
     grej = 1.0 - gg*xmax + xmax*xmax*(1.0 - gg + (1.0 - gg*y)/(y*y));
 
     do {
       rndmEngine->flatArray(2, rndm);
       x = xmin*xmax/(xmin*(1.0 - rndm[0]) + xmax*rndm[0]);
       y = 1.0 - x;
       z = 1.0 - gg*x + x*x*(1.0 - gg + (1.0 - gg*y)/(y*y));
       /*
       if(z > grej) {
         G4cout << "G4MollerBhabhaModel::SampleSecondary Warning! "
                << "Majorant " << grej << " < "
                << z << " for x= " << x
                << " e-e- scattering"
                << G4endl;
       }
       */
       // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
     } while(grej * rndm[1] > z);
 
   //Bhabha (e+e-) scattering
   } else {
 
     G4double y   = 1.0/(1.0 + gam);
     G4double y2  = y*y;
     G4double y12 = 1.0 - 2.0*y;
     G4double b1  = 2.0 - y2;
     G4double b2  = y12*(3.0 + y2);
     G4double y122= y12*y12;
     G4double b4  = y122*y12;
     G4double b3  = b4 + y122;
 
     y    = xmax*xmax;
     grej = 1.0 + (y*y*b4 - xmin*xmin*xmin*b3 + y*b2 - xmin*b1)*beta2; 
     do {
       rndmEngine->flatArray(2, rndm);
       x = xmin*xmax/(xmin*(1.0 - rndm[0]) + xmax*rndm[0]);
       y = x*x;
       z = 1.0 + (y*y*b4 - x*y*b3 + y*b2 - x*b1)*beta2; 
       /*
       if(z > grej) {
         G4cout << "G4MollerBhabhaModel::SampleSecondary Warning! "
                << "Majorant " << grej << " < "
                << z << " for x= " << x
                << " e+e- scattering"
                << G4endl;
       }
       */
       // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
     } while(grej * rndm[1] > z);
   }
 
   G4double deltaKinEnergy = x * kineticEnergy;
 
   G4ThreeVector deltaDirection;
 
   if(UseAngularGeneratorFlag()) {
     const G4Material* mat =  couple->GetMaterial();
     G4int Z = SelectRandomAtomNumber(mat);
 
     deltaDirection = 
       GetAngularDistribution()->SampleDirection(dp, deltaKinEnergy, Z, mat);
 
   } else {
  
     G4double deltaMomentum =
       sqrt(deltaKinEnergy * (deltaKinEnergy + 2.0*electron_mass_c2));
     G4double cost = deltaKinEnergy * (energy + electron_mass_c2) /
       (deltaMomentum * dp->GetTotalMomentum());
     if(cost > 1.0) { cost = 1.0; }
     G4double sint = sqrt((1.0 - cost)*(1.0 + cost));
 
     G4double phi = twopi * rndmEngine->flat() ;
 
     deltaDirection.set(sint*cos(phi),sint*sin(phi), cost) ;
     deltaDirection.rotateUz(dp->GetMomentumDirection());
   }  
 
   // create G4DynamicParticle object for delta ray
   G4DynamicParticle* delta = 
     new G4DynamicParticle(theElectron,deltaDirection,deltaKinEnergy);
   vdp->push_back(delta);
 
   // primary change
   kineticEnergy -= deltaKinEnergy;
   G4ThreeVector finalP = dp->GetMomentum() - delta->GetMomentum();
   finalP               = finalP.unit();
 
   fParticleChange->SetProposedKineticEnergy(kineticEnergy);
   fParticleChange->SetProposedMomentumDirection(finalP);
 }

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void G4MollerBhabhaModel::SetParticle ( const G4ParticleDefinition * p )

inlineprotected

Definition at line 133 of file G4MollerBhabhaModel.hh.

 {
   particle = p;
   if(p != theElectron) { isElectron = false; }
 }

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Member Data Documentation

G4ParticleChangeForLoss* G4MollerBhabhaModel::fParticleChange

protected

Definition at line 115 of file G4MollerBhabhaModel.hh.

G4bool G4MollerBhabhaModel::isElectron

protected

Definition at line 117 of file G4MollerBhabhaModel.hh.

G4double G4MollerBhabhaModel::lowLimit

protected

Definition at line 119 of file G4MollerBhabhaModel.hh.

const G4ParticleDefinition* G4MollerBhabhaModel::particle

protected

Definition at line 113 of file G4MollerBhabhaModel.hh.

G4ParticleDefinition* G4MollerBhabhaModel::theElectron

protected

Definition at line 114 of file G4MollerBhabhaModel.hh.

G4double G4MollerBhabhaModel::twoln10

protected

Definition at line 118 of file G4MollerBhabhaModel.hh.

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

geant4.10.03.p01/source/processes/electromagnetic/standard/include/G4MollerBhabhaModel.hh
geant4.10.03.p01/source/processes/electromagnetic/standard/src/G4MollerBhabhaModel.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation