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geant4/source/processes/electromagnetic/standard/src/G4PhotoElectricEffect52.cc
T
Gabriele Cosmo fe73f43734 Import Geant4 8.2.0 source tree
2016-06-09 14:55:03 +02:00

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//
// ********************************************************************
// * License and Disclaimer *
// * *
// * The Geant4 software is copyright of the Copyright Holders of *
// * the Geant4 Collaboration. It is provided under the terms and *
// * conditions of the Geant4 Software License, included in the file *
// * LICENSE and available at http://cern.ch/geant4/license . These *
// * include a list of copyright holders. *
// * *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work make any representation or warranty, express or implied, *
// * regarding this software system or assume any liability for its *
// * use. Please see the license in the file LICENSE and URL above *
// * for the full disclaimer and the limitation of liability. *
// * *
// * This code implementation is the result of the scientific and *
// * technical work of the GEANT4 collaboration. *
// * By using, copying, modifying or distributing the software (or *
// * any work based on the software) you agree to acknowledge its *
// * use in resulting scientific publications, and indicate your *
// * acceptance of all terms of the Geant4 Software license. *
// ********************************************************************
//
//
// $Id: G4PhotoElectricEffect52.cc,v 1.3 2006/10/16 15:26:49 vnivanch Exp $
// GEANT4 tag $Name: geant4-08-02 $
//
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
// 12-06-96, Added SelectRandomAtom() method, by M.Maire
// 21-06-96, SetCuts implementation, M.Maire
// 17-09-96, PartialSumSigma(i)
// split of ComputeBindingEnergy, M.Maire
// 08-01-97, crossection table + meanfreepath table, M.Maire
// 13-03-97, adapted for the new physics scheme, M.Maire
// 28-03-97, protection in BuildPhysicsTable, M.Maire
// 04-06-98, in DoIt, secondary production condition:
// range > std::min(threshold,safety)
// 13-08-98, new methods SetBining() PrintInfo()
// 17-11-98, use table of Atomic shells in PostStepDoIt
// 06-01-99, use Sandia crossSection below 50 keV, V.Grichine mma
// 20-05-99, protection against very low energy photons ,L.Urban
// 08-06-99, removed this above protection from the DoIt. mma
// 21-06-00, in DoIt, killing photon: aParticleChange.SetEnergyChange(0.); mma
// 22-06-00, in DoIt, absorbe very low energy photon (back to 20-05-99); mma
// 22-02-01, back to 08-06-99 after correc in SandiaTable (materials-V03-00-05)
// 28-05-01, V.Ivanchenko minor changes to provide ANSI -wall compilation
// 13-07-01, DoIt: suppression of production cut of the electron (mma)
// 06-08-01, new methods Store/Retrieve PhysicsTable (mma)
// 06-08-01, BuildThePhysicsTable() called from constructor (mma)
// 17-09-01, migration of Materials to pure STL (mma)
// 20-09-01, DoIt: fminimalEnergy of generated electron = 1*eV (mma)
// 01-10-01, come back to BuildPhysicsTable(const G4ParticleDefinition&)
// 10-01-02, moved few function from icc to cc
// 17-04-02, Keep only Sandia crossSections. Remove BuildPhysicsTables.
// Simplify public interface (mma)
// 29-04-02, Generate theta angle of the photoelectron from Sauter-Gavrila
// distribution (mma)
// 15-01-03, photoelectron theta ditribution : return costeta=1 if gamma>5
// (helmut burkhardt)
// 04-05-05, Add 52 to class name (V.Ivanchenko)
//
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
#include "G4PhotoElectricEffect52.hh"
#include "G4UnitsTable.hh"
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
using namespace std;
G4PhotoElectricEffect52::G4PhotoElectricEffect52(const G4String& processName,
G4ProcessType type):G4VDiscreteProcess (processName, type),
fminimalEnergy(1*eV)
{ PrintInfoDefinition();}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
// destructor
G4PhotoElectricEffect52::~G4PhotoElectricEffect52()
{ }
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
inline G4bool G4PhotoElectricEffect52::IsApplicable(const G4ParticleDefinition&
particle)
{
return ( &particle == G4Gamma::Gamma() );
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
G4double G4PhotoElectricEffect52::ComputeCrossSectionPerAtom(G4double GammaEnergy,
G4double AtomicNumber)
// returns the photoElectric cross Section in GEANT4 internal units
{
G4double* SandiaCof
= G4SandiaTable::GetSandiaCofPerAtom((int)AtomicNumber,GammaEnergy);
G4double energy2 = GammaEnergy*GammaEnergy, energy3 = GammaEnergy*energy2,
energy4 = energy2*energy2;
return SandiaCof[0]/GammaEnergy + SandiaCof[1]/energy2 +
SandiaCof[2]/energy3 + SandiaCof[3]/energy4;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
G4double G4PhotoElectricEffect52::ComputeMeanFreePath(G4double GammaEnergy,
G4Material* aMaterial)
// returns the gamma mean free path in GEANT4 internal units
{
G4double* SandiaCof = aMaterial->GetSandiaTable()
->GetSandiaCofForMaterial(GammaEnergy);
G4double energy2 = GammaEnergy*GammaEnergy, energy3 = GammaEnergy*energy2,
energy4 = energy2*energy2;
G4double SIGMA = SandiaCof[0]/GammaEnergy + SandiaCof[1]/energy2 +
SandiaCof[2]/energy3 + SandiaCof[3]/energy4;
return SIGMA > DBL_MIN ? 1./SIGMA : DBL_MAX;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
inline G4double G4PhotoElectricEffect52::GetMeanFreePath(const G4Track& aTrack,
G4double,
G4ForceCondition*)
// returns the gamma mean free path in GEANT4 internal units
{
G4double GammaEnergy = aTrack.GetDynamicParticle()->GetKineticEnergy();
G4double* SandiaCof = aTrack.GetMaterial()->GetSandiaTable()
->GetSandiaCofForMaterial(GammaEnergy);
G4double energy2 = GammaEnergy*GammaEnergy, energy3 = GammaEnergy*energy2,
energy4 = energy2*energy2;
G4double SIGMA = SandiaCof[0]/GammaEnergy + SandiaCof[1]/energy2 +
SandiaCof[2]/energy3 + SandiaCof[3]/energy4;
MeanFreePath = SIGMA > DBL_MIN ? 1./SIGMA : DBL_MAX;
return MeanFreePath;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
G4VParticleChange* G4PhotoElectricEffect52::PostStepDoIt(const G4Track& aTrack,
const G4Step& aStep)
//
// Generate an electron resulting of a photo electric effect.
// The incident photon disappear.
// GEANT4 internal units
//
{ aParticleChange.Initialize(aTrack);
G4Material* aMaterial = aTrack.GetMaterial();
const G4DynamicParticle* aDynamicPhoton = aTrack.GetDynamicParticle();
G4double PhotonEnergy = aDynamicPhoton->GetKineticEnergy();
G4ParticleMomentum PhotonDirection = aDynamicPhoton->GetMomentumDirection();
// select randomly one element constituing the material.
G4Element* anElement = SelectRandomAtom(aDynamicPhoton, aMaterial);
//
// Photo electron
//
G4int NbOfShells = anElement->GetNbOfAtomicShells();
G4int i=0;
while ((i<NbOfShells)&&(PhotonEnergy<anElement->GetAtomicShell(i))) i++;
if (i==NbOfShells) return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
G4double ElecKineEnergy = PhotonEnergy - anElement->GetAtomicShell(i);
if (ElecKineEnergy > fminimalEnergy)
{
// direction of the photo electron
//
G4double cosTeta = ElecThetaDistribution(ElecKineEnergy);
G4double sinTeta = sqrt(1.-cosTeta*cosTeta);
G4double Phi = twopi * G4UniformRand();
G4double dirx = sinTeta*cos(Phi),diry = sinTeta*sin(Phi),dirz = cosTeta;
G4ThreeVector ElecDirection(dirx,diry,dirz);
ElecDirection.rotateUz(PhotonDirection);
//
G4DynamicParticle* aElectron = new G4DynamicParticle (
G4Electron::Electron(),ElecDirection, ElecKineEnergy);
aParticleChange.SetNumberOfSecondaries(1);
aParticleChange.AddSecondary(aElectron);
}
else
{
ElecKineEnergy = 0.;
aParticleChange.SetNumberOfSecondaries(0);
}
//
// Kill the incident photon
//
aParticleChange.ProposeLocalEnergyDeposit(PhotonEnergy-ElecKineEnergy);
aParticleChange.ProposeEnergy(0.);
aParticleChange.ProposeTrackStatus(fStopAndKill);
// Reset NbOfInteractionLengthLeft and return aParticleChange
return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
G4Element* G4PhotoElectricEffect52::SelectRandomAtom(
const G4DynamicParticle* aDynamicPhoton,
G4Material* aMaterial)
{
// select randomly 1 element within the material
const G4int NumberOfElements = aMaterial->GetNumberOfElements();
const G4ElementVector* theElementVector = aMaterial->GetElementVector();
if (NumberOfElements == 1) return (*theElementVector)[0];
G4double GammaEnergy = aDynamicPhoton->GetKineticEnergy();
const G4double* NbOfAtomsPerVolume = aMaterial->GetVecNbOfAtomsPerVolume();
G4double PartialSumSigma = 0. ;
G4double rval = G4UniformRand();
for ( G4int elm=0 ; elm < NumberOfElements ; elm++ )
{PartialSumSigma += NbOfAtomsPerVolume[elm] *
ComputeCrossSectionPerAtom(GammaEnergy,
(*theElementVector)[elm]->GetZ());
if (rval<=PartialSumSigma*MeanFreePath) return ((*theElementVector)[elm]);
}
return ((*theElementVector)[NumberOfElements-1]);
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
G4double G4PhotoElectricEffect52::ElecThetaDistribution(G4double kineEnergy)
{
// Compute Theta distribution of the emitted electron, with respect to the
// incident Gamma.
// The Sauter-Gavrila distribution for the K-shell is used.
//
G4double costeta = 1.;
G4double gamma = 1. + kineEnergy/electron_mass_c2;
if (gamma > 5.) return costeta;
G4double beta = sqrt(gamma*gamma-1.)/gamma;
G4double b = 0.5*gamma*(gamma-1.)*(gamma-2);
G4double rndm,term,greject,grejsup;
if (gamma < 2.) grejsup = gamma*gamma*(1.+b-beta*b);
else grejsup = gamma*gamma*(1.+b+beta*b);
do { rndm = 1.-2*G4UniformRand();
costeta = (rndm+beta)/(rndm*beta+1.);
term = 1.-beta*costeta;
greject = (1.-costeta*costeta)*(1.+b*term)/(term*term);
} while(greject < G4UniformRand()*grejsup);
return costeta;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
void G4PhotoElectricEffect52::PrintInfoDefinition()
{
G4String comments = "Total cross sections from Sandia parametrisation. ";
G4cout << G4endl << GetProcessName() << ": " << comments << G4endl;
G4cout << " WARNING: This process is obsolete and will be soon removed"
<< G4endl;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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