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geant4/source/processes/hadronic/cross_sections/include/G4ElectroNuclearCrossSection.hh
T
Gabriele Cosmo 1d812b78b1 Import Geant4 6.1.0 source tree
2016-06-09 10:49:58 +02:00

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//
// ********************************************************************
// * 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. *
// ********************************************************************
//
//
// GEANT4 tag $Name: gcross-V05-02-01 $
//
//
// GEANT4 physics class: G4ElectroNuclearCrossSection -- header file
// M.V. Kossov, ITEP(Moscow), 24-OCT-01
// The last update: M.V. Kossov, CERN/ITEP (Moscow) 25-Sept-03
//
#ifndef G4ElectroNuclearCrossSection_h
#define G4ElectroNuclearCrossSection_h 1
#include "G4VCrossSectionDataSet.hh"
#include "G4DynamicParticle.hh"
#include "G4Element.hh"
#include "G4ParticleTable.hh"
#include "G4NucleiProperties.hh"
#include "G4NucleiPropertiesTable.hh"
#include <vector>
#include "Randomize.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
class G4ElectroNuclearCrossSection : public G4VCrossSectionDataSet
{
public:
G4ElectroNuclearCrossSection() // Constructor @@??
{
//theHadronCrossSections = G4HadronCrossSections::Instance();
}
~G4ElectroNuclearCrossSection() {}
G4bool IsApplicable(const G4DynamicParticle* aParticle, const G4Element* )
{
//return theHadronCrossSections->IsApplicable(aParticle, anElement);
// Possible prototype
G4bool result = false;
if( aParticle->GetDefinition()==G4Electron::ElectronDefinition()) result = true;
if( aParticle->GetDefinition()==G4Positron::PositronDefinition()) result = true;
return result;
}
G4double GetCrossSection(const G4DynamicParticle* aParticle, const G4Element* anElement,
G4double T=0.);
G4double GetEquivalentPhotonEnergy();
G4double GetVirtualFactor(G4double nu, G4double Q2);
G4double GetEquivalentPhotonQ2(G4double nu);
void BuildPhysicsTable(const G4ParticleDefinition&) {}
void DumpPhysicsTable(const G4ParticleDefinition&) {}
private:
G4int GetFunctions(G4double a, G4double* x, G4double* y, G4double* z);
//G4double LinearFit(G4double X, G4int N, const G4double* XN, const G4double* YN);
G4double ThresholdEnergy(G4int Z, G4int N);
G4double HighEnergyJ1(G4double lE);
G4double HighEnergyJ2(G4double lE);
G4double HighEnergyJ3(G4double lE);
G4double SolveTheEquation(G4double f);
G4double Fun(G4double x);
G4double DFun(G4double x);
// Body
private:
static G4int lastN; // The last N of calculated nucleus
static G4int lastZ; // The last Z of calculated nucleus
static G4int lastF; // Last used in the cross section TheFirstBin
static G4double* lastJ1; // Pointer to the last array of the J1 function
static G4double* lastJ2; // Pointer to the last array of the J2 function
static G4double* lastJ3; // Pointer to the last array of the J3 function
static G4int lastL; // Last used in the cross section TheLastBin
static G4double lastE; // Last used in the cross section Energy
static G4double lastTH; // Last value of the Energy Threshold
static G4double lastSig; // Last value of the Cross Section
static G4double lastG; // Last value of gamma=lnE-ln(me)
static G4double lastH; // Last value of the High energy A-dependence
};
// Gives the threshold energy for different nuclei (min of p- and n-threshold)
inline G4double G4ElectroNuclearCrossSection::ThresholdEnergy(G4int Z, G4int N)
{
// CHIPS - Direct GEANT
//static const G4double mNeut = G4QPDGCode(2112).GetMass();
//static const G4double mProt = G4QPDGCode(2212).GetMass();
static const G4double mNeut = G4NucleiProperties::GetNuclearMass(1,0);
static const G4double mProt = G4NucleiProperties::GetNuclearMass(1,1);
// ---------
static const G4double infEn = 9.e27;
G4int A=Z+N;
if(A<1) return infEn;
else if(A==1) return 134.9766; // Pi0 threshold for the nucleon
// CHIPS - Direct GEANT
//G4double mT= G4QPDGCode(111).GetNuclMass(Z,N,0);
G4double mT= 0.;
if(G4NucleiPropertiesTable::IsInTable(Z,A)) mT=G4NucleiProperties::GetNuclearMass(A,Z);
else return 0.; // If it is not in the Table of Stable Nuclei, then the Threshold=0
// ---------
G4double mP= infEn;
//if(Z) mP= G4QPDGCode(111).GetNuclMass(Z-1,N,0);
if(Z&&G4NucleiPropertiesTable::IsInTable(Z-1,A-1)) mP=G4NucleiProperties::GetNuclearMass(A-1,Z-1);
else return infEn;
G4double mN= infEn;
//if(N) mN= G4QPDGCode(111).GetNuclMass(Z,N-1,0);
if(N&&G4NucleiPropertiesTable::IsInTable(Z,A-1)) mN=G4NucleiProperties::GetNuclearMass(A-1,Z);
else return infEn;
G4double dP= mP+mProt-mT;
G4double dN= mN+mNeut-mT;
if(dP<dN)dN=dP;
return dN;
}
inline G4double G4ElectroNuclearCrossSection::DFun(G4double x)// Parametrization of the PhotoNucCS
{
static const G4double shd=1.0734; // HE PomShadowing(D)
static const G4double poc=0.0375; // HE Pomeron coefficient
static const G4double pos=16.5; // HE Pomeron shift
static const G4double reg=.11; // HE Reggeon slope
static const G4double mel=0.5109989; // Mass of an electron in MeV
static const G4double lmel=log(mel); // Log of an electron mass
G4double y=exp(x-lastG-lmel); // y for the x
G4double flux=lastG*(2.-y*(2.-y))-1.; // flux factor
return (poc*(x-pos)+shd*exp(-reg*x))*flux;
}
inline G4double G4ElectroNuclearCrossSection::Fun(G4double x) // Integrated PhoNuc cross section
{
G4double dlg1=lastG+lastG-1.;
G4double lgoe=lastG/lastE;
G4double HE2=HighEnergyJ2(x);
return dlg1*HighEnergyJ1(x)-lgoe*(HE2+HE2-HighEnergyJ3(x)/lastE);
}
inline G4double G4ElectroNuclearCrossSection::HighEnergyJ1(G4double lEn)
{
static const G4double le=log(50000.); // log(E0)
static const G4double le2=le*le; // log(E0)^2
static const G4double a=.0375; // a
static const G4double ha=a*.5; // a/2
static const G4double ab=a*16.5; // a*b
static const G4double d=0.11; // d
static const G4double cd=1.0734/d; // c/d
static const G4double ele=exp(-d*le); // E0^(-d)
return ha*(lEn*lEn-le2)-ab*(lEn-le)-cd*(exp(-d*lEn)-ele);
}
inline G4double G4ElectroNuclearCrossSection::HighEnergyJ2(G4double lEn)
{
static const G4double e=50000.; // E0
static const G4double le=log(e); // log(E0)
static const G4double le1=(le-1.)*e; // (log(E0)-1)*E0
static const G4double a=.0375; // a
static const G4double ab=a*16.5; // a*b
static const G4double d=1.-0.11; // 1-d
static const G4double cd=1.0734/d; // c/(1-d)
static const G4double ele=exp(d*le); // E0^(1-d)
G4double En=exp(lEn);
return a*((lEn-1.)*En-le1)-ab*(En-e)+cd*(exp(d*lEn)-ele);
}
inline G4double G4ElectroNuclearCrossSection::HighEnergyJ3(G4double lEn)
{
static const G4double e=50000.; // E0
static const G4double le=log(e); // log(E0)
static const G4double e2=e*e; // E0^2
static const G4double leh=(le-.5)*e2; // (log(E0)-.5)*E0^2
static const G4double ha=.0375*.5; // a/2
static const G4double hab=ha*16.5; // a*b/2
static const G4double d=2.-.11; // 2-d
static const G4double cd=1.0734/d; // c/(2-d)
static const G4double ele=exp(d*le); // E0^(2-d)
G4double lastE2=exp(lEn+lEn);
return ha*((lEn-.5)*lastE2-leh)-hab*(lastE2-e2)+cd*(exp(d*lEn)-ele);
}
#endif
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