#include <G4MuPairProductionModel.hh>

Inheritance diagram for G4MuPairProductionModel:

Public Member Functions
	G4MuPairProductionModel (const G4ParticleDefinition *p=nullptr, const G4String &nam="muPairProd")

virtual	~G4MuPairProductionModel ()

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

virtual void	InitialiseLocal (const G4ParticleDefinition , G4VEmModel masterModel) override

virtual G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *, G4double kineticEnergy, G4double Z, G4double A, 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

virtual G4double	MinPrimaryEnergy (const G4Material , const G4ParticleDefinition , G4double) override

void	SetLowestKineticEnergy (G4double e)

void	SetParticle (const G4ParticleDefinition *)

G4MuPairProductionModel &	operator= (const G4MuPairProductionModel &right)=delete

	G4MuPairProductionModel (const G4MuPairProductionModel &)=delete

Public Member Functions inherited from G4VEmModel
	G4VEmModel (const G4String &nam)

virtual	~G4VEmModel ()

virtual void	Initialise (const G4ParticleDefinition *, const G4DataVector &)=0

virtual void	SampleSecondaries (std::vector< G4DynamicParticle * > , const G4MaterialCutsCouple , const G4DynamicParticle *, G4double tmin=0.0, G4double tmax=DBL_MAX)=0

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

virtual G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *, G4double kinEnergy, G4double Z, G4double A=0., G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

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)

const G4Element *	SelectRandomAtom (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

const G4Element *	SelectTargetAtom (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double logKineticEnergy, 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 *)

G4int	SelectIsotopeNumber (const G4Element *)

void	SetParticleChange (G4VParticleChange , G4VEmFluctuationModel f=nullptr)

void	SetCrossSectionTable (G4PhysicsTable *, G4bool isLocal)

G4ElementData *	GetElementData ()

G4PhysicsTable *	GetCrossSectionTable ()

G4VEmFluctuationModel *	GetModelOfFluctuations ()

G4VEmAngularDistribution *	GetAngularDistribution ()

G4VEmModel *	GetTripletModel ()

void	SetTripletModel (G4VEmModel *)

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) const

void	SetPolarAngleLimit (G4double)

void	SetSecondaryThreshold (G4double)

void	SetLPMFlag (G4bool val)

void	SetDeexcitationFlag (G4bool val)

void	SetForceBuildTable (G4bool val)

void	SetFluctuationFlag (G4bool val)

void	SetMasterThread (G4bool val)

G4bool	IsMaster () const

void	SetUseBaseMaterials (G4bool val)

G4bool	UseBaseMaterials () 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)

G4VEmModel &	operator= (const G4VEmModel &right)=delete

	G4VEmModel (const G4VEmModel &)=delete

Protected Member Functions
G4double	ComputMuPairLoss (G4double Z, G4double tkin, G4double cut, G4double tmax)

G4double	ComputeMicroscopicCrossSection (G4double tkin, G4double Z, G4double cut)

virtual G4double	ComputeDMicroscopicCrossSection (G4double tkin, G4double Z, G4double pairEnergy)

G4double	MaxSecondaryEnergyForElement (G4double kineticEnergy, G4double Z)

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 *)

Protected Attributes
const G4ParticleDefinition *	particle

G4NistManager *	nist

G4double	factorForCross

G4double	sqrte

G4double	particleMass

G4double	z13

G4double	z23

G4double	lnZ

G4int	currentZ

G4ParticleDefinition *	theElectron

G4ParticleDefinition *	thePositron

G4ParticleChangeForLoss *	fParticleChange

G4double	minPairEnergy

G4double	lowestKinEnergy

G4int	nYBinPerDecade

size_t	nbiny

size_t	nbine

G4double	ymin

G4double	dy

G4double	emin

G4double	emax

G4bool	fTableToFile

Protected Attributes inherited from G4VEmModel
G4ElementData *	fElementData

G4VParticleChange *	pParticleChange

G4PhysicsTable *	xSectionTable

const G4Material *	pBaseMaterial

const std::vector< G4double > *	theDensityFactor

const std::vector< G4int > *	theDensityIdx

size_t	idxTable

G4bool	lossFlucFlag

G4double	inveplus

G4double	pFactor

Detailed Description

Definition at line 71 of file G4MuPairProductionModel.hh.

Constructor & Destructor Documentation

◆ G4MuPairProductionModel() [1/2]

G4MuPairProductionModel::G4MuPairProductionModel	(	const G4ParticleDefinition *	p = `nullptr`,
		const G4String &	nam = `"muPairProd"`
	)

explicit

Definition at line 112 of file G4MuPairProductionModel.cc.

  : G4VEmModel(nam),
    particle(nullptr),
    factorForCross(4.*fine_structure_const*fine_structure_const
                   *classic_electr_radius*classic_electr_radius/(3.*pi)),
    sqrte(sqrt(G4Exp(1.))),
    currentZ(0),
    fParticleChange(nullptr),
    minPairEnergy(4.*electron_mass_c2),
    lowestKinEnergy(1.0*GeV),
    nYBinPerDecade(4),
    nbiny(1000),
    nbine(0),
    ymin(-5.),
    dy(0.005),
    fTableToFile(false)
{
  nist = G4NistManager::Instance();
 
  theElectron = G4Electron::Electron();
  thePositron = G4Positron::Positron();
 
  particleMass = lnZ = z13 = z23 = 0.;
 
  // setup lowest limit dependent on particle mass
  if(p) { 
    SetParticle(p); 
    lowestKinEnergy = std::max(lowestKinEnergy,p->GetPDGMass()*8.0); 
  }
  emin = lowestKinEnergy;
  emax = 10.*TeV;
  SetAngularDistribution(new G4ModifiedMephi());
}

◆ ~G4MuPairProductionModel()

G4MuPairProductionModel::~G4MuPairProductionModel ( )

virtual

Definition at line 149 of file G4MuPairProductionModel.cc.

150{}

◆ G4MuPairProductionModel() [2/2]

G4MuPairProductionModel::G4MuPairProductionModel ( const G4MuPairProductionModel & )

delete

Member Function Documentation

◆ ComputeCrossSectionPerAtom()

G4double G4MuPairProductionModel::ComputeCrossSectionPerAtom	(	const G4ParticleDefinition *	,
		G4double	kineticEnergy,
		G4double	Z,
		G4double	A,
		G4double	cutEnergy,
		G4double	maxEnergy
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 447 of file G4MuPairProductionModel.cc.

{
  G4double cross = 0.0;
  if (kineticEnergy <= lowestKinEnergy) { return cross; }
 
  G4double maxPairEnergy = MaxSecondaryEnergyForElement(kineticEnergy, Z);
  G4double tmax = std::min(maxEnergy, maxPairEnergy);
  G4double cut  = std::max(cutEnergy, minPairEnergy);
  if (cut >= tmax) { return cross; }
 
  cross = ComputeMicroscopicCrossSection(kineticEnergy, Z, cut);
  if(tmax < kineticEnergy) {
    cross -= ComputeMicroscopicCrossSection(kineticEnergy, Z, tmax);
  }
  return cross;
}

◆ ComputeDEDXPerVolume()

G4double G4MuPairProductionModel::ComputeDEDXPerVolume	(	const G4Material *	material,
		const G4ParticleDefinition *	,
		G4double	kineticEnergy,
		G4double	cutEnergy
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 208 of file G4MuPairProductionModel.cc.

{
  G4double dedx = 0.0;
  if (cutEnergy <= minPairEnergy || kineticEnergy <= lowestKinEnergy)
    { return dedx; }
 
  const G4ElementVector* theElementVector = material->GetElementVector();
  const G4double* theAtomicNumDensityVector =
                                   material->GetAtomicNumDensityVector();
 
  //  loop for elements in the material
  for (size_t i=0; i<material->GetNumberOfElements(); ++i) {
     G4double Z = (*theElementVector)[i]->GetZ();
     G4double tmax = MaxSecondaryEnergyForElement(kineticEnergy, Z);
     G4double loss = ComputMuPairLoss(Z, kineticEnergy, cutEnergy, tmax);
     dedx += loss*theAtomicNumDensityVector[i];
  }
  dedx = std::max(dedx, 0.0);
  return dedx;
}

◆ ComputeDMicroscopicCrossSection()

G4double G4MuPairProductionModel::ComputeDMicroscopicCrossSection	(	G4double	tkin,
		G4double	Z,
		G4double	pairEnergy
	)

protectedvirtual

Definition at line 310 of file G4MuPairProductionModel.cc.

{
  static const G4double bbbtf= 183. ;
  static const G4double bbbh = 202.4 ;
  static const G4double g1tf = 1.95e-5 ;
  static const G4double g2tf = 5.3e-5 ;
  static const G4double g1h  = 4.4e-5 ;
  static const G4double g2h  = 4.8e-5 ;
 
  if (pairEnergy <= 4.0 * electron_mass_c2)
    return 0.0;
 
  G4double totalEnergy  = tkin + particleMass;
  G4double residEnergy  = totalEnergy - pairEnergy;
 
  if (residEnergy <= 0.75*sqrte*z13*particleMass)
    return 0.0;
 
  G4double a0 = 1.0 / (totalEnergy * residEnergy);
  G4double alf = 4.0 * electron_mass_c2 / pairEnergy;
  G4double rt = sqrt(1.0 - alf);
  G4double delta = 6.0 * particleMass * particleMass * a0;
  G4double tmnexp = alf/(1.0 + rt) + delta*rt;
 
  if(tmnexp >= 1.0) { return 0.0; }
 
  G4double tmn = G4Log(tmnexp);
 
  G4double massratio      = particleMass/electron_mass_c2;
  G4double massratio2     = massratio*massratio;
  G4double inv_massratio2 = 1.0 / massratio2;
 
  // zeta calculation
  G4double bbb,g1,g2;
  if( Z < 1.5 ) { bbb = bbbh ; g1 = g1h ; g2 = g2h ; }
  else          { bbb = bbbtf; g1 = g1tf; g2 = g2tf; }
 
  G4double zeta = 0.0;
  G4double z1exp = totalEnergy / (particleMass + g1*z23*totalEnergy);
 
  // 35.221047195922 is the root of zeta1(x) = 0.073 * log(x) - 0.26, so the
  // condition below is the same as zeta1 > 0.0, but without calling log(x)
  if (z1exp > 35.221047195922)
  {
    G4double z2exp = totalEnergy / (particleMass + g2*z13*totalEnergy);
    zeta = (0.073 * G4Log(z1exp) - 0.26) / (0.058 * G4Log(z2exp) - 0.14);
  }
 
  G4double z2 = Z*(Z+zeta);
  G4double screen0 = 2.*electron_mass_c2*sqrte*bbb/(z13*pairEnergy);
  G4double beta = 0.5*pairEnergy*pairEnergy*a0;
  G4double xi0 = 0.5*massratio2*beta;
 
  // Gaussian integration in ln(1-ro) ( with 8 points)
  G4double rho[8];
  G4double rho2[8];
  G4double xi[8];
  G4double xi1[8];
  G4double xii[8];
 
  for (G4int i = 0; i < 8; ++i)
  {
    rho[i] = G4Exp(tmn*xgi[i]) - 1.0; // rho = -asymmetry
    rho2[i] = rho[i] * rho[i];
    xi[i] = xi0*(1.0-rho2[i]);
    xi1[i] = 1.0 + xi[i];
    xii[i] = 1.0 / xi[i];
  }
 
  G4double ye1[8];
  G4double ym1[8];
 
  G4double b40 = 4.0 * beta;
  G4double b62 = 6.0 * beta + 2.0;
 
  for (G4int i = 0; i < 8; ++i)
  {
    G4double yeu = (b40 + 5.0) + (b40 - 1.0) * rho2[i];
    G4double yed = b62 * G4Log(3.0 + xii[i]) + (2.0 * beta - 1.0) * rho2[i] - b40;
 
    G4double ymu = b62 * (1.0 + rho2[i]) + 6.0;
    G4double ymd = (b40 + 3.0) * (1.0 + rho2[i]) * G4Log(3.0 + xi[i]) + 2.0 - 3.0 * rho2[i];
 
    ye1[i] = 1.0 + yeu / yed;
    ym1[i] = 1.0 + ymu / ymd;
  }
 
  G4double be[8];
  G4double bm[8];
 
  for(G4int i = 0; i < 8; ++i)
  {
    if(xi[i] <= 1000.0) {
      be[i] = ((2.0 + rho2[i]) * (1.0 + beta) + xi[i] * (3.0 + rho2[i])) *
                G4Log(1.0 + xii[i]) + (1.0 - rho2[i] - beta) / xi1[i] - (3.0 + rho2[i]);
    } else {
      be[i] = 0.5 * (3.0 - rho2[i] + 2.0 * beta * (1.0 + rho2[i])) * xii[i];
    }
 
    if(xi[i] >= 0.001) {
      G4double a10 = (1.0 + 2.0 * beta) * (1.0 - rho2[i]);
      bm[i] = ((1.0 + rho2[i]) * (1.0 + 1.5 * beta) - a10 * xii[i]) * G4Log(xi1[i]) +
                xi[i] * (1.0 - rho2[i] - beta) / xi1[i] + a10;
    } else {
      bm[i] = 0.5 * (5.0 - rho2[i] + beta * (3.0 + rho2[i])) * xi[i];
    }
  }
 
  G4double sum = 0.0;
 
  for (G4int i = 0; i < 8; ++i)
  {
    G4double screen = screen0*xi1[i]/(1.0-rho2[i]) ;
    G4double ale = G4Log(bbb/z13*sqrt(xi1[i]*ye1[i])/(1.+screen*ye1[i])) ;
    G4double cre = 0.5*G4Log(1.+2.25*z23*xi1[i]*ye1[i]*inv_massratio2) ;
 
    G4double fe = (ale-cre)*be[i];
    fe *= (fe > 0.0);
 
    G4double alm_crm = G4Log(bbb*massratio/(1.5*z23*(1.+screen*ym1[i])));
    G4double fm = alm_crm*bm[i];
    fm *= (fm > 0.0) * inv_massratio2;
 
    sum += wgi[i]*(1.0 + rho[i])*(fe+fm);
  }
 
  return -tmn*sum*factorForCross*z2*residEnergy/(totalEnergy*pairEnergy);
}

Referenced by ComputeMicroscopicCrossSection(), and ComputMuPairLoss().

◆ ComputeMicroscopicCrossSection()

G4double G4MuPairProductionModel::ComputeMicroscopicCrossSection	(	G4double	tkin,
		G4double	Z,
		G4double	cut
	)

protected

Definition at line 272 of file G4MuPairProductionModel.cc.

{
  G4double cross = 0.;
  G4double tmax = MaxSecondaryEnergyForElement(tkin, Z);
  G4double cut  = std::max(cutEnergy, minPairEnergy);
  if (tmax <= cut) { return cross; }
 
  //  G4double ak1=6.9 ;
  // G4double ak2=1.0 ;
  G4double aaa = G4Log(cut);
  G4double bbb = G4Log(tmax);
  G4int kkk = (G4int)((bbb-aaa)/ak1 + ak2);
  if(kkk > 8) { kkk = 8; }
  else if (kkk < 1) { kkk = 1; }
 
  G4double hhh = (bbb-aaa)/G4double(kkk);
  G4double x = aaa;
 
  for(G4int l=0; l<kkk; ++l)
  {
    for(G4int i=0; i<8; ++i)
    {
      G4double ep = G4Exp(x + xgi[i]*hhh);
      cross += ep*wgi[i]*ComputeDMicroscopicCrossSection(tkin, Z, ep);
    }
    x += hhh;
  }
 
  cross *= hhh;
  cross = std::max(cross, 0.0);
  return cross;
}

Referenced by ComputeCrossSectionPerAtom().

◆ ComputMuPairLoss()

G4double G4MuPairProductionModel::ComputMuPairLoss	(	G4double	Z,
		G4double	tkin,
		G4double	cut,
		G4double	tmax
	)

protected

Definition at line 235 of file G4MuPairProductionModel.cc.

{
  G4double loss = 0.0;
 
  G4double cut = std::min(cutEnergy,tmax);
  if(cut <= minPairEnergy) { return loss; }
 
  // calculate the rectricted loss
  // numerical integration in log(PairEnergy)
  G4double aaa = G4Log(minPairEnergy);
  G4double bbb = G4Log(cut);
 
  G4int    kkk = (G4int)((bbb-aaa)/ak1+ak2);
  if (kkk > 8)      { kkk = 8; }
  else if (kkk < 1) { kkk = 1; }
 
  G4double hhh = (bbb-aaa)/(G4double)kkk;
  G4double x = aaa;
 
  for (G4int l=0 ; l<kkk; ++l) {
    for (G4int ll=0; ll<8; ++ll)
    {
      G4double ep = G4Exp(x+xgi[ll]*hhh);
      loss += wgi[ll]*ep*ep*ComputeDMicroscopicCrossSection(tkin, Z, ep);
    }
    x += hhh;
  }
  loss *= hhh;
  loss = std::max(loss, 0.0);
  return loss;
}

Referenced by ComputeDEDXPerVolume().

◆ Initialise()

void G4MuPairProductionModel::Initialise	(	const G4ParticleDefinition *	p,
		const G4DataVector &	cuts
	)

overridevirtual

Implements G4VEmModel.

Definition at line 163 of file G4MuPairProductionModel.cc.

{ 
  SetParticle(p); 
  if(!fParticleChange) { fParticleChange = GetParticleChangeForLoss(); }
 
  // for low-energy application this process should not work
  if(lowestKinEnergy >= HighEnergyLimit()) { return; }
 
  // define scale of internal table for each thread only once
  if(0 == nbine) {
    emin = std::max(lowestKinEnergy, LowEnergyLimit());
    emax = std::max(HighEnergyLimit(), emin*2);
    nbine = size_t(nYBinPerDecade*std::log10(emax/emin));
    if(nbine < 3) { nbine = 3; }
 
    ymin = G4Log(minPairEnergy/emin);
    dy   = -ymin/G4double(nbiny);
  }
 
  if(IsMaster() && p == particle) { 
    if(!fElementData) { 
      fElementData = new G4ElementData();
      G4bool dataFile = G4EmParameters::Instance()->RetrieveMuDataFromFile();
      if(dataFile)  { dataFile = RetrieveTables(); }
      if(!dataFile) { MakeSamplingTables(); }
      if(fTableToFile) { StoreTables(); }
    }    
    InitialiseElementSelectors(p, cuts); 
  }
}

◆ InitialiseLocal()

void G4MuPairProductionModel::InitialiseLocal	(	const G4ParticleDefinition *	p,
		G4VEmModel *	masterModel
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 197 of file G4MuPairProductionModel.cc.

{
  if(p == particle && lowestKinEnergy < HighEnergyLimit()) {
    SetElementSelectors(masterModel->GetElementSelectors());
    fElementData = masterModel->GetElementData();
  }
}

◆ MaxSecondaryEnergyForElement()

G4double G4MuPairProductionModel::MaxSecondaryEnergyForElement	(	G4double	kineticEnergy,
		G4double	Z
	)

inlineprotected

Definition at line 199 of file G4MuPairProductionModel.hh.

{
  G4int Z = G4lrint(ZZ);
  if(Z != currentZ) {
    currentZ = Z;
    z13 = nist->GetZ13(Z);
    z23 = z13*z13;
    lnZ = nist->GetLOGZ(Z);
  }
  return kineticEnergy + particleMass*(1.0 - 0.75*sqrte*z13);
}

Referenced by ComputeCrossSectionPerAtom(), ComputeDEDXPerVolume(), ComputeMicroscopicCrossSection(), and SampleSecondaries().

◆ MinPrimaryEnergy()

G4double G4MuPairProductionModel::MinPrimaryEnergy	(	const G4Material *	,
		const G4ParticleDefinition *	,
		G4double	cut
	)

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 154 of file G4MuPairProductionModel.cc.

{
  return std::max(lowestKinEnergy,cut);
}

◆ operator=()

G4MuPairProductionModel & G4MuPairProductionModel::operator= ( const G4MuPairProductionModel & right )

delete

◆ SampleSecondaries()

void G4MuPairProductionModel::SampleSecondaries	(	std::vector< G4DynamicParticle * > *	vdp,
		const G4MaterialCutsCouple *	couple,
		const G4DynamicParticle *	aDynamicParticle,
		G4double	tmin,
		G4double	maxEnergy
	)

overridevirtual

Implements G4VEmModel.

Definition at line 540 of file G4MuPairProductionModel.cc.

{
  G4double kinEnergy = aDynamicParticle->GetKineticEnergy();
  //G4cout << "------- G4MuPairProductionModel::SampleSecondaries E(MeV)= " 
  //         << kinEnergy << "  " 
  //         << aDynamicParticle->GetDefinition()->GetParticleName() << G4endl;
  G4double totalEnergy   = kinEnergy + particleMass;
  G4double totalMomentum = 
    sqrt(kinEnergy*(kinEnergy + 2.0*particleMass));
 
  G4ThreeVector partDirection = aDynamicParticle->GetMomentumDirection();
 
  // select randomly one element constituing the material
  const G4Element* anElement = SelectRandomAtom(couple,particle,kinEnergy);
 
  // define interval of energy transfer
  G4double maxPairEnergy = MaxSecondaryEnergyForElement(kinEnergy, 
                                                        anElement->GetZ());
  G4double maxEnergy     = std::min(tmax, maxPairEnergy);
  G4double minEnergy     = std::max(tmin, minPairEnergy);
 
  if(minEnergy >= maxEnergy) { return; }
  //G4cout << "emin= " << minEnergy << " emax= " << maxEnergy 
  // << " minPair= " << minPairEnergy << " maxpair= " << maxPairEnergy 
  //    << " ymin= " << ymin << " dy= " << dy << G4endl;
 
  G4double coeff = G4Log(minPairEnergy/kinEnergy)/ymin;
 
  // compute limits 
  G4double yymin = G4Log(minEnergy/kinEnergy)/coeff;
  G4double yymax = G4Log(maxEnergy/kinEnergy)/coeff;
 
  //G4cout << "yymin= " << yymin << "  yymax= " << yymax << G4endl;
 
  // units should not be used, bacause table was built without
  G4double logTkin = G4Log(kinEnergy/MeV);
 
  // sample e-e+ energy, pair energy first
 
  // select sample table via Z
  G4int iz1(0), iz2(0);
  for(G4int iz=0; iz<nzdat; ++iz) { 
    if(currentZ == zdat[iz]) {
      iz1 = iz2 = currentZ; 
      break;
    } else if(currentZ < zdat[iz]) {
      iz2 = zdat[iz];
      if(iz > 0) { iz1 = zdat[iz-1]; }
      else { iz1 = iz2; }
      break;
    } 
  }
  if(0 == iz1) { iz1 = iz2 = zdat[nzdat-1]; }
 
  G4double pairEnergy = 0.0;
  G4int count = 0;
  //G4cout << "start loop Z1= " << iz1 << " Z2= " << iz2 << G4endl;
  do {
    ++count;
    // sampling using only one random number
    G4double rand = G4UniformRand();
  
    G4double x = FindScaledEnergy(iz1, rand, logTkin, yymin, yymax);
    if(iz1 != iz2) {
      G4double x2 = FindScaledEnergy(iz2, rand, logTkin, yymin, yymax);
      G4double lz1= nist->GetLOGZ(iz1);
      G4double lz2= nist->GetLOGZ(iz2);
      //G4cout << count << ".  x= " << x << "  x2= " << x2 
      //             << " Z1= " << iz1 << " Z2= " << iz2 << G4endl;
      x += (x2 - x)*(lnZ - lz1)/(lz2 - lz1);
    }
    //G4cout << "x= " << x << "  coeff= " << coeff << G4endl;
    pairEnergy = kinEnergy*G4Exp(x*coeff);
    
    // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
  } while((pairEnergy < minEnergy || pairEnergy > maxEnergy) && 10 > count);
 
  //G4cout << "## pairEnergy(GeV)= " << pairEnergy/GeV 
  //         << " Etot(GeV)= " << totalEnergy/GeV << G4endl; 
 
  // sample r=(E+-E-)/pairEnergy  ( uniformly .....)
  G4double rmax =
    (1.-6.*particleMass*particleMass/(totalEnergy*(totalEnergy-pairEnergy)))
                                       *sqrt(1.-minPairEnergy/pairEnergy);
  G4double r = rmax * (-1.+2.*G4UniformRand()) ;
 
  // compute energies from pairEnergy,r
  G4double eEnergy = (1.-r)*pairEnergy*0.5;
  G4double pEnergy = pairEnergy - eEnergy;
 
  // Sample angles 
  G4ThreeVector eDirection, pDirection;
  //
  GetAngularDistribution()->SamplePairDirections(aDynamicParticle, 
                                                 eEnergy, pEnergy,
                                                 eDirection, pDirection);
  // create G4DynamicParticle object for e+e-
  eEnergy = std::max(eEnergy - CLHEP::electron_mass_c2, 0.0);
  pEnergy = std::max(pEnergy - CLHEP::electron_mass_c2, 0.0);
  G4DynamicParticle* aParticle1 =
    new G4DynamicParticle(theElectron,eDirection,eEnergy);
  G4DynamicParticle* aParticle2 = 
    new G4DynamicParticle(thePositron,pDirection,pEnergy);
  // Fill output vector
  vdp->push_back(aParticle1);
  vdp->push_back(aParticle2);
 
  // primary change
  kinEnergy -= pairEnergy;
  partDirection *= totalMomentum;
  partDirection -= (aParticle1->GetMomentum() + aParticle2->GetMomentum());
  partDirection = partDirection.unit();
 
  // if energy transfer is higher than threshold (very high by default)
  // then stop tracking the primary particle and create a new secondary
  if (pairEnergy > SecondaryThreshold()) {
    fParticleChange->ProposeTrackStatus(fStopAndKill);
    fParticleChange->SetProposedKineticEnergy(0.0);
    G4DynamicParticle* newdp = 
      new G4DynamicParticle(particle, partDirection, kinEnergy);
    vdp->push_back(newdp);
  } else { // continue tracking the primary e-/e+ otherwise
    fParticleChange->SetProposedMomentumDirection(partDirection);
    fParticleChange->SetProposedKineticEnergy(kinEnergy);
  }
  //G4cout << "-- G4MuPairProductionModel::SampleSecondaries done" << G4endl; 
}

◆ SetLowestKineticEnergy()

void G4MuPairProductionModel::SetLowestKineticEnergy ( G4double e )

inline

Definition at line 180 of file G4MuPairProductionModel.hh.

{
  lowestKinEnergy = e;
}

Referenced by G4ePairProduction::InitialiseEnergyLossProcess(), and G4MuPairProduction::InitialiseEnergyLossProcess().

◆ SetParticle()

void G4MuPairProductionModel::SetParticle ( const G4ParticleDefinition * p )

inline

Definition at line 188 of file G4MuPairProductionModel.hh.

{
  if(!particle) {
    particle = p;
    particleMass = particle->GetPDGMass();
  }
}

Referenced by G4MuPairProductionModel(), and Initialise().

Member Data Documentation

◆ currentZ

G4int G4MuPairProductionModel::currentZ

protected

Definition at line 157 of file G4MuPairProductionModel.hh.

Referenced by MaxSecondaryEnergyForElement(), and SampleSecondaries().

◆ dy

G4double G4MuPairProductionModel::dy

protected

Definition at line 171 of file G4MuPairProductionModel.hh.

Referenced by Initialise().

◆ emax

G4double G4MuPairProductionModel::emax

protected

Definition at line 173 of file G4MuPairProductionModel.hh.

Referenced by G4MuPairProductionModel(), and Initialise().

◆ emin

G4double G4MuPairProductionModel::emin

protected

Definition at line 172 of file G4MuPairProductionModel.hh.

Referenced by G4MuPairProductionModel(), and Initialise().

◆ factorForCross

G4double G4MuPairProductionModel::factorForCross

protected

Definition at line 151 of file G4MuPairProductionModel.hh.

Referenced by ComputeDMicroscopicCrossSection().

◆ fParticleChange

G4ParticleChangeForLoss* G4MuPairProductionModel::fParticleChange

protected

Definition at line 161 of file G4MuPairProductionModel.hh.

Referenced by Initialise(), and SampleSecondaries().

◆ fTableToFile

G4bool G4MuPairProductionModel::fTableToFile

protected

Definition at line 175 of file G4MuPairProductionModel.hh.

Referenced by Initialise().

◆ lnZ

G4double G4MuPairProductionModel::lnZ

protected

Definition at line 156 of file G4MuPairProductionModel.hh.

Referenced by G4MuPairProductionModel(), MaxSecondaryEnergyForElement(), and SampleSecondaries().

◆ lowestKinEnergy

G4double G4MuPairProductionModel::lowestKinEnergy

protected

Definition at line 164 of file G4MuPairProductionModel.hh.

Referenced by ComputeCrossSectionPerAtom(), ComputeDEDXPerVolume(), G4MuPairProductionModel(), Initialise(), InitialiseLocal(), MinPrimaryEnergy(), and SetLowestKineticEnergy().

◆ minPairEnergy

G4double G4MuPairProductionModel::minPairEnergy

protected

Definition at line 163 of file G4MuPairProductionModel.hh.

Referenced by ComputeCrossSectionPerAtom(), ComputeDEDXPerVolume(), ComputeMicroscopicCrossSection(), ComputMuPairLoss(), Initialise(), and SampleSecondaries().

◆ nbine

size_t G4MuPairProductionModel::nbine

protected

Definition at line 169 of file G4MuPairProductionModel.hh.

Referenced by Initialise().

◆ nbiny

size_t G4MuPairProductionModel::nbiny

protected

Definition at line 168 of file G4MuPairProductionModel.hh.

Referenced by Initialise().

◆ nist

G4NistManager* G4MuPairProductionModel::nist

protected

Definition at line 149 of file G4MuPairProductionModel.hh.

Referenced by G4MuPairProductionModel(), MaxSecondaryEnergyForElement(), and SampleSecondaries().

◆ nYBinPerDecade

G4int G4MuPairProductionModel::nYBinPerDecade

protected

Definition at line 167 of file G4MuPairProductionModel.hh.

Referenced by Initialise().

◆ particle

const G4ParticleDefinition* G4MuPairProductionModel::particle

protected

Definition at line 148 of file G4MuPairProductionModel.hh.

Referenced by Initialise(), InitialiseLocal(), SampleSecondaries(), and SetParticle().

◆ particleMass

G4double G4MuPairProductionModel::particleMass

protected

Definition at line 153 of file G4MuPairProductionModel.hh.

Referenced by ComputeDMicroscopicCrossSection(), G4MuPairProductionModel(), MaxSecondaryEnergyForElement(), SampleSecondaries(), and SetParticle().

◆ sqrte

G4double G4MuPairProductionModel::sqrte

protected

Definition at line 152 of file G4MuPairProductionModel.hh.

Referenced by ComputeDMicroscopicCrossSection(), and MaxSecondaryEnergyForElement().

◆ theElectron

G4ParticleDefinition* G4MuPairProductionModel::theElectron

protected

Definition at line 159 of file G4MuPairProductionModel.hh.

Referenced by G4MuPairProductionModel(), and SampleSecondaries().

◆ thePositron

G4ParticleDefinition* G4MuPairProductionModel::thePositron

protected

Definition at line 160 of file G4MuPairProductionModel.hh.

Referenced by G4MuPairProductionModel(), and SampleSecondaries().

◆ ymin

G4double G4MuPairProductionModel::ymin

protected

Definition at line 170 of file G4MuPairProductionModel.hh.

Referenced by Initialise(), and SampleSecondaries().

◆ z13

G4double G4MuPairProductionModel::z13

protected

Definition at line 154 of file G4MuPairProductionModel.hh.

Referenced by ComputeDMicroscopicCrossSection(), G4MuPairProductionModel(), and MaxSecondaryEnergyForElement().

◆ z23

G4double G4MuPairProductionModel::z23

protected

Definition at line 155 of file G4MuPairProductionModel.hh.

Referenced by ComputeDMicroscopicCrossSection(), G4MuPairProductionModel(), and MaxSecondaryEnergyForElement().

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

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ G4MuPairProductionModel() [1/2]

◆ ~G4MuPairProductionModel()

◆ G4MuPairProductionModel() [2/2]

Member Function Documentation

◆ ComputeCrossSectionPerAtom()

◆ ComputeDEDXPerVolume()

◆ ComputeDMicroscopicCrossSection()

◆ ComputeMicroscopicCrossSection()

◆ ComputMuPairLoss()

◆ Initialise()

◆ InitialiseLocal()

◆ MaxSecondaryEnergyForElement()

◆ MinPrimaryEnergy()

◆ operator=()

◆ SampleSecondaries()

◆ SetLowestKineticEnergy()

◆ SetParticle()

Member Data Documentation

◆ currentZ

◆ dy

◆ emax

◆ emin

◆ factorForCross

◆ fParticleChange

◆ fTableToFile

◆ lnZ

◆ lowestKinEnergy

◆ minPairEnergy

◆ nbine

◆ nbiny

◆ nist

◆ nYBinPerDecade

◆ particle

◆ particleMass

◆ sqrte

◆ theElectron

◆ thePositron

◆ ymin

◆ z13

◆ z23