G4mplIonisationModel Class Reference

#include <G4mplIonisationModel.hh>

Inheritance diagram for G4mplIonisationModel:

Public Member Functions
	G4mplIonisationModel (G4double mCharge, const G4String &nam="mplIonisation")
virtual	~G4mplIonisationModel ()
virtual void	Initialise (const G4ParticleDefinition *, const G4DataVector &)
virtual G4double	ComputeDEDXPerVolume (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy)
virtual void	SampleSecondaries (std::vector< G4DynamicParticle * > *, const G4MaterialCutsCouple *, const G4DynamicParticle *, G4double tmin, G4double maxEnergy)
virtual G4double	SampleFluctuations (const G4Material *, const G4DynamicParticle *, G4double &tmax, G4double &length, G4double &meanLoss)
virtual G4double	Dispersion (const G4Material *, const G4DynamicParticle *, G4double &tmax, G4double &length)
void	SetParticle (const G4ParticleDefinition *p)

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Detailed Description

Definition at line 57 of file G4mplIonisationModel.hh.

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Constructor & Destructor Documentation

G4mplIonisationModel::G4mplIonisationModel	(	G4double	mCharge,
		const G4String &	nam = "mplIonisation"
	)

Definition at line 67 of file G4mplIonisationModel.cc.

References G4INCL::Math::pi.

  : G4VEmModel(nam),G4VEmFluctuationModel(nam),
  magCharge(mCharge),
  twoln10(log(100.0)),
  betalow(0.01),
  betalim(0.1),
  beta2lim(betalim*betalim),
  bg2lim(beta2lim*(1.0 + beta2lim))
{
  nmpl         = G4int(abs(magCharge) * 2 * fine_structure_const + 0.5);
  if(nmpl > 6)      { nmpl = 6; }
  else if(nmpl < 1) { nmpl = 1; }
  pi_hbarc2_over_mc2 = pi * hbarc * hbarc / electron_mass_c2;
  chargeSquare = magCharge * magCharge;
  dedxlim = 45.*nmpl*nmpl*GeV*cm2/g;
  fParticleChange = 0;
  monopole = 0;
  mass = 0.0;
}

G4mplIonisationModel::~G4mplIonisationModel

(

)

[virtual]

Definition at line 89 of file G4mplIonisationModel.cc.

{}

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Member Function Documentation

G4double G4mplIonisationModel::ComputeDEDXPerVolume	(	const G4Material *	,
		const G4ParticleDefinition *	,
		G4double	kineticEnergy,
		G4double	cutEnergy
	)			[virtual]

Reimplemented from G4VEmModel.

Definition at line 117 of file G4mplIonisationModel.cc.

References G4InuclParticleNames::gam, G4Material::GetDensity(), and SetParticle().

{
  if(!monopole) { SetParticle(p); }
  G4double tau   = kineticEnergy / mass;
  G4double gam   = tau + 1.0;
  G4double bg2   = tau * (tau + 2.0);
  G4double beta2 = bg2 / (gam * gam);
  G4double beta  = sqrt(beta2);

  // low-energy asymptotic formula
  G4double dedx  = dedxlim*beta*material->GetDensity();

  // above asymptotic
  if(beta > betalow) {

    // high energy
    if(beta >= betalim) {
      dedx = ComputeDEDXAhlen(material, bg2);

    } else {

      G4double dedx1 = dedxlim*betalow*material->GetDensity();
      G4double dedx2 = ComputeDEDXAhlen(material, bg2lim);

      // extrapolation between two formula 
      G4double kapa2 = beta - betalow;
      G4double kapa1 = betalim - beta;
      dedx = (kapa1*dedx1 + kapa2*dedx2)/(kapa1 + kapa2);
    }
  }
  return dedx;
}

G4double G4mplIonisationModel::Dispersion	(	const G4Material *	,
		const G4DynamicParticle *	,
		G4double &	tmax,
		G4double &	length
	)			[virtual]

Implements G4VEmFluctuationModel.

Definition at line 233 of file G4mplIonisationModel.cc.

References G4InuclParticleNames::gam, G4Material::GetElectronDensity(), and G4DynamicParticle::GetKineticEnergy().

Referenced by SampleFluctuations().

{
  G4double siga = 0.0;
  G4double tau   = dp->GetKineticEnergy()/mass;
  if(tau > 0.0) { 
    G4double electronDensity = material->GetElectronDensity();
    G4double gam   = tau + 1.0;
    G4double invbeta2 = (gam*gam)/(tau * (tau+2.0));
    siga  = (invbeta2 - 0.5) * twopi_mc2_rcl2 * tmax * length
      * electronDensity * chargeSquare;
  }
  return siga;
}

void G4mplIonisationModel::Initialise	(	const G4ParticleDefinition *	,
		const G4DataVector &
	)			[virtual]

Implements G4VEmModel.

Definition at line 108 of file G4mplIonisationModel.cc.

References G4VEmModel::GetParticleChangeForLoss(), and SetParticle().

{
  if(!monopole) { SetParticle(p); }
  if(!fParticleChange) { fParticleChange = GetParticleChangeForLoss(); }
}

G4double G4mplIonisationModel::SampleFluctuations	(	const G4Material *	,
		const G4DynamicParticle *	,
		G4double &	tmax,
		G4double &	length,
		G4double &	meanLoss
	)			[virtual]

Implements G4VEmFluctuationModel.

Definition at line 205 of file G4mplIonisationModel.cc.

References Dispersion(), and G4UniformRand.

{
  G4double siga = Dispersion(material,dp,tmax,length);
  G4double loss = meanLoss;
  siga = sqrt(siga);
  G4double twomeanLoss = meanLoss + meanLoss;

  if(twomeanLoss < siga) {
    G4double x;
    do {
      loss = twomeanLoss*G4UniformRand();
      x = (loss - meanLoss)/siga;
    } while (1.0 - 0.5*x*x < G4UniformRand());
  } else {
    do {
      loss = G4RandGauss::shoot(meanLoss,siga);
    } while (0.0 > loss || loss > twomeanLoss);
  }
  return loss;
}

void G4mplIonisationModel::SampleSecondaries	(	std::vector< G4DynamicParticle * > *	,
		const G4MaterialCutsCouple *	,
		const G4DynamicParticle *	,
		G4double	tmin,
		G4double	maxEnergy
	)			[virtual]

Implements G4VEmModel.

Definition at line 196 of file G4mplIonisationModel.cc.

{}

void G4mplIonisationModel::SetParticle

(

const G4ParticleDefinition *

p

)

Definition at line 94 of file G4mplIonisationModel.cc.

References G4ParticleDefinition::GetPDGMass(), G4VEmModel::HighEnergyLimit(), G4VEmModel::LowEnergyLimit(), G4VEmModel::SetHighEnergyLimit(), and G4VEmModel::SetLowEnergyLimit().

Referenced by ComputeDEDXPerVolume(), and Initialise().

{
  monopole = p;
  mass     = monopole->GetPDGMass();
  G4double emin = 
    std::min(LowEnergyLimit(),0.1*mass*(1/sqrt(1 - betalow*betalow) - 1)); 
  G4double emax = 
    std::max(HighEnergyLimit(),10*mass*(1/sqrt(1 - beta2lim) - 1)); 
  SetLowEnergyLimit(emin);
  SetHighEnergyLimit(emax);
}

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

• G4mplIonisationModel.hh
• G4mplIonisationModel.cc

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