Gabriele Cosmo
227 lines
7.3 KiB
C++
227 lines
7.3 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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//
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// -------------------------------------------------------------------
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//
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// GEANT4 Class file
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//
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//
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// File name: G4hBetheBlochModel
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//
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// Author: V.Ivanchenko (Vladimir.Ivanchenko@cern.ch)
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//
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// Creation date: 20 July 2000
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//
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// Modifications:
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// 20/07/2000 V.Ivanchenko First implementation
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// 03/10/2000 V.Ivanchenko clean up accoding to CodeWizard
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//
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// Class Description:
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//
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// Bethe-Bloch ionisation model
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//
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// Class Description: End
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//
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// -------------------------------------------------------------------
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//
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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#include "G4hBetheBlochModel.hh"
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#include "G4DynamicParticle.hh"
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#include "G4ParticleDefinition.hh"
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#include "G4Material.hh"
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#include "globals.hh"
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4hBetheBlochModel::G4hBetheBlochModel(const G4String& name)
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: G4VLowEnergyModel(name),
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lowEnergyLimit(1.*MeV),
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highEnergyLimit(100.*GeV),
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twoln10(2.*log(10.)),
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bg2lim(0.0169),
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taulim(8.4146e-3)
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{;}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4hBetheBlochModel::~G4hBetheBlochModel()
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{;}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::TheValue(const G4DynamicParticle* particle,
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const G4Material* material)
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{
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G4double energy = particle->GetKineticEnergy() ;
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G4double particleMass = particle->GetMass() ;
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G4double eloss = BetheBlochFormula(material,energy,particleMass) ;
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return eloss ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::TheValue(const G4ParticleDefinition* aParticle,
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const G4Material* material,
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G4double kineticEnergy)
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{
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G4double particleMass = aParticle->GetPDGMass() ;
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G4double eloss = BetheBlochFormula(material,kineticEnergy,particleMass) ;
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return eloss ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::HighEnergyLimit(
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const G4ParticleDefinition* aParticle,
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const G4Material* material) const
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{
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return highEnergyLimit ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::LowEnergyLimit(
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const G4ParticleDefinition* aParticle,
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const G4Material* material) const
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{
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G4double taul = (material->GetIonisation()->GetTaul())*
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(aParticle->GetPDGMass()) ;
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return taul ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::HighEnergyLimit(
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const G4ParticleDefinition* aParticle) const
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{
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return highEnergyLimit ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::LowEnergyLimit(
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const G4ParticleDefinition* aParticle) const
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{
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return lowEnergyLimit ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4bool G4hBetheBlochModel::IsInCharge(const G4DynamicParticle* particle,
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const G4Material* material) const
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{
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return true ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4bool G4hBetheBlochModel::IsInCharge(const G4ParticleDefinition* aParticle,
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const G4Material* material) const
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{
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return true ;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4hBetheBlochModel::BetheBlochFormula(
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const G4Material* material,
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G4double kineticEnergy,
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G4double particleMass) const
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{
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// This member function is applied normally to proton/antiproton
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G4double ionloss ;
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G4double rateMass = electron_mass_c2/particleMass ;
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G4double taul = material->GetIonisation()->GetTaul() ;
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G4double tau = kineticEnergy/particleMass ; // tau is relative energy
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// It is not normal case for this function
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// for low energy parametrisation have to be applied
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if ( tau < taul ) tau = taul ;
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// some local variables
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G4double gamma,bg2,beta2,tmax,x,delta,sh ;
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G4double electronDensity = material->GetElectronDensity();
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G4double eexc = material->GetIonisation()->GetMeanExcitationEnergy();
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G4double eexc2 = eexc*eexc ;
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G4double cden = material->GetIonisation()->GetCdensity();
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G4double mden = material->GetIonisation()->GetMdensity();
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G4double aden = material->GetIonisation()->GetAdensity();
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G4double x0den = material->GetIonisation()->GetX0density();
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G4double x1den = material->GetIonisation()->GetX1density();
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G4double* shellCorrectionVector =
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material->GetIonisation()->GetShellCorrectionVector();
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gamma = tau + 1.0 ;
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bg2 = tau*(tau+2.0) ;
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beta2 = bg2/(gamma*gamma) ;
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tmax = 2.*electron_mass_c2*bg2/(1.+2.*gamma*rateMass+rateMass*rateMass) ;
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ionloss = log(2.0*electron_mass_c2*bg2*tmax/eexc2)-2.0*beta2 ;
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// density correction
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x = log(bg2)/twoln10 ;
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if ( x < x0den ) {
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delta = 0.0 ;
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} else {
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delta = twoln10*x - cden ;
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if ( x < x1den ) delta += aden*pow((x1den-x),mden) ;
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}
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// shell correction
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sh = 0.0 ;
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x = 1.0 ;
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if ( bg2 > bg2lim ) {
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for (G4int k=0; k<=2; k++) {
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x *= bg2 ;
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sh += shellCorrectionVector[k]/x;
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}
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} else {
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for (G4int k=0; k<=2; k++) {
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x *= bg2lim ;
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sh += shellCorrectionVector[k]/x;
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}
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sh *= log(tau/taul)/log(taulim/taul) ;
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}
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// now compute the total ionization loss
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ionloss -= delta + sh ;
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ionloss *= twopi_mc2_rcl2*electronDensity/beta2 ;
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if ( ionloss < 0.0) ionloss = 0.0 ;
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return ionloss;
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}
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