Gabriele Cosmo
160 lines
6.1 KiB
C++
160 lines
6.1 KiB
C++
//
|
|
// ********************************************************************
|
|
// * DISCLAIMER *
|
|
// * *
|
|
// * The following disclaimer summarizes all the specific disclaimers *
|
|
// * of contributors to this software. The specific disclaimers,which *
|
|
// * govern, are listed with their locations in: *
|
|
// * http://cern.ch/geant4/license *
|
|
// * *
|
|
// * 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. *
|
|
// * *
|
|
// * This code implementation is the intellectual property of the *
|
|
// * GEANT4 collaboration. *
|
|
// * By copying, distributing or modifying the Program (or any work *
|
|
// * based on the Program) you indicate your acceptance of this *
|
|
// * statement, and all its terms. *
|
|
// ********************************************************************
|
|
//
|
|
//
|
|
// $Id: G4RToEConvForGamma.cc,v 1.1 2003/09/19 14:47:01 gcosmo Exp $
|
|
// GEANT4 tag $Name: geant4-06-00-patch-01 $
|
|
//
|
|
//
|
|
// --------------------------------------------------------------
|
|
// GEANT 4 class implementation file/ History:
|
|
// 5 Oct. 2002, H.Kuirashige : Structure created based on object model
|
|
// --------------------------------------------------------------
|
|
|
|
#include "G4RToEConvForGamma.hh"
|
|
#include "G4ParticleDefinition.hh"
|
|
#include "G4ParticleTable.hh"
|
|
#include "G4Material.hh"
|
|
#include "G4PhysicsLogVector.hh"
|
|
|
|
#include "G4ios.hh"
|
|
#include <iomanip>
|
|
#include <strstream>
|
|
|
|
G4RToEConvForGamma::G4RToEConvForGamma() : G4VRangeToEnergyConverter()
|
|
{
|
|
theParticle = G4ParticleTable::GetParticleTable()->FindParticle("gamma");
|
|
if (theParticle ==0) {
|
|
#ifdef G4VERBOSE
|
|
if (GetVerboseLevel()>0) {
|
|
G4cout << " G4RToEConvForGamma::G4RToEConvForGamma() ";
|
|
G4cout << " Gamma is not defined !!" << G4endl;
|
|
}
|
|
#endif
|
|
}
|
|
TotBin = 100;
|
|
}
|
|
|
|
G4RToEConvForGamma::~G4RToEConvForGamma()
|
|
{
|
|
}
|
|
|
|
|
|
// ***********************************************************************
|
|
// ******************* BuildAbsorptionLengthVector ***********************
|
|
// ***********************************************************************
|
|
void G4RToEConvForGamma::BuildAbsorptionLengthVector(
|
|
const G4Material* aMaterial,
|
|
G4double ,
|
|
G4double ,
|
|
G4RangeVector* absorptionLengthVector )
|
|
{
|
|
// fill the absorption length vector for this material
|
|
// absorption length is defined here as
|
|
//
|
|
// absorption length = 5./ macroscopic absorption cross section
|
|
//
|
|
const G4CrossSectionTable* aCrossSectionTable = (G4CrossSectionTable*)(theLossTable);
|
|
const G4ElementVector* elementVector = aMaterial->GetElementVector();
|
|
const G4double* atomicNumDensityVector = aMaterial->GetAtomicNumDensityVector();
|
|
|
|
// fill absorption length vector
|
|
G4int NumEl = aMaterial->GetNumberOfElements();
|
|
G4double absorptionLengthMax = 0.0;
|
|
for (size_t ibin=0; ibin<size_t(TotBin); ibin++) {
|
|
G4double lowEdgeEnergy = absorptionLengthVector->GetLowEdgeEnergy(ibin);
|
|
|
|
G4double SIGMA = 0. ;
|
|
|
|
for (size_t iel=0; iel<size_t(NumEl); iel++) {
|
|
G4bool isOut;
|
|
G4int IndEl = (*elementVector)[iel]->GetIndex();
|
|
SIGMA += atomicNumDensityVector[iel]*
|
|
(*aCrossSectionTable)[IndEl]->GetValue(lowEdgeEnergy,isOut);
|
|
}
|
|
// absorption length=5./SIGMA
|
|
absorptionLengthVector->PutValue(ibin, 5./SIGMA);
|
|
if (absorptionLengthMax < 5./SIGMA ) absorptionLengthMax = 5./SIGMA;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
// ***********************************************************************
|
|
// ********************** ComputeCrossSection ****************************
|
|
// ***********************************************************************
|
|
G4double G4RToEConvForGamma::ComputeCrossSection(G4double AtomicNumber,
|
|
G4double KineticEnergy) const
|
|
{
|
|
// Compute the "absorption" cross section of the photon "absorption"
|
|
// cross section means here the sum of the cross sections of the
|
|
// pair production, Compton scattering and photoelectric processes
|
|
static G4double Z;
|
|
const G4double t1keV = 1.*keV;
|
|
const G4double t200keV = 200.*keV;
|
|
const G4double t100MeV = 100.*MeV;
|
|
|
|
static G4double s200keV, s1keV;
|
|
static G4double tmin, tlow;
|
|
static G4double smin, slow;
|
|
static G4double cmin, clow, chigh;
|
|
// compute Z dependent quantities in the case of a new AtomicNumber
|
|
if(abs(AtomicNumber-Z)>0.1) {
|
|
Z = AtomicNumber;
|
|
G4double Zsquare = Z*Z;
|
|
G4double Zlog = log(Z);
|
|
G4double Zlogsquare = Zlog*Zlog;
|
|
|
|
s200keV = (0.2651-0.1501*Zlog+0.02283*Zlogsquare)*Zsquare;
|
|
tmin = (0.552+218.5/Z+557.17/Zsquare)*MeV;
|
|
smin = (0.01239+0.005585*Zlog-0.000923*Zlogsquare)*exp(1.5*Zlog);
|
|
cmin=log(s200keV/smin)/(log(tmin/t200keV)*log(tmin/t200keV));
|
|
tlow = 0.2*exp(-7.355/sqrt(Z))*MeV;
|
|
slow = s200keV*exp(0.042*Z*log(t200keV/tlow)*log(t200keV/tlow));
|
|
s1keV = 300.*Zsquare;
|
|
clow =log(s1keV/slow)/log(tlow/t1keV);
|
|
|
|
chigh=(7.55e-5-0.0542e-5*Z)*Zsquare*Z/log(t100MeV/tmin);
|
|
}
|
|
|
|
// calculate the cross section (using an approximate empirical formula)
|
|
G4double s;
|
|
if ( KineticEnergy<tlow ) {
|
|
if(KineticEnergy<t1keV) s = slow*exp(clow*log(tlow/t1keV));
|
|
else s = slow*exp(clow*log(tlow/KineticEnergy));
|
|
|
|
} else if ( KineticEnergy<t200keV ) {
|
|
s = s200keV
|
|
* exp(0.042*Z*log(t200keV/KineticEnergy)*log(t200keV/KineticEnergy));
|
|
|
|
} else if( KineticEnergy<tmin ){
|
|
s = smin
|
|
* exp(cmin*log(tmin/KineticEnergy)*log(tmin/KineticEnergy));
|
|
|
|
} else {
|
|
s = smin + chigh*log(KineticEnergy/tmin);
|
|
|
|
}
|
|
return s * barn;
|
|
}
|
|
|