source: trunk/source/processes/hadronic/cross_sections/include/G4ElectroNuclearCrossSection.hh@ 1201

Last change on this file since 1201 was 1196, checked in by garnier, 16 years ago

update CVS release candidate geant4.9.3.01
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[819]1//
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[1196]27// GEANT4 tag $Name: geant4-09-03-cand-01 $
[819]28//
29//
30// GEANT4 physics class: G4ElectroNuclearCrossSection -- header file
31// M.V. Kossov, ITEP(Moscow), 24-OCT-01
32// The last update: M.V. Kossov, CERN/ITEP (Moscow) 25-Sept-03
33//
34
35#ifndef G4ElectroNuclearCrossSection_h
36#define G4ElectroNuclearCrossSection_h 1
37
38#include "G4VCrossSectionDataSet.hh"
39#include "G4DynamicParticle.hh"
40#include "G4Element.hh"
41#include "G4ParticleTable.hh"
42#include "G4NucleiProperties.hh"
43#include <vector>
44#include "Randomize.hh"
45#include "G4Electron.hh"
46#include "G4Positron.hh"
47
48class G4ElectroNuclearCrossSection : public G4VCrossSectionDataSet
49{
50public:
51
52 G4ElectroNuclearCrossSection();
53 virtual ~G4ElectroNuclearCrossSection();
54
55 G4bool IsApplicable(const G4DynamicParticle* aParticle, const G4Element* )
56 {
57 return IsZAApplicable(aParticle, 0., 0.);
58 }
59
60 G4bool IsZAApplicable(const G4DynamicParticle* aParticle, G4double /*ZZ*/,
61 G4double /*AA*/)
62 {
63 G4bool result = false;
64 if( aParticle->GetDefinition()==G4Electron::ElectronDefinition()) result = true;
65 if( aParticle->GetDefinition()==G4Positron::PositronDefinition()) result = true;
66 return result;
67 }
68
69
70 G4double GetCrossSection(const G4DynamicParticle* aParticle,
71 const G4Element* anElement, G4double T=0.);
72
73 G4double GetIsoZACrossSection(const G4DynamicParticle* aParticle,
74 G4double ZZ, G4double AA, G4double T=0.);
75
76
77 G4double GetEquivalentPhotonEnergy();
78
79 G4double GetVirtualFactor(G4double nu, G4double Q2);
80
81 G4double GetEquivalentPhotonQ2(G4double nu);
82
83 void BuildPhysicsTable(const G4ParticleDefinition&) {}
84
85 void DumpPhysicsTable(const G4ParticleDefinition&) {}
86
87private:
88 G4int GetFunctions(G4double a, G4double* x, G4double* y, G4double* z);
89 //G4double LinearFit(G4double X, G4int N, const G4double* XN, const G4double* YN);
90 G4double ThresholdEnergy(G4int Z, G4int N);
91 G4double HighEnergyJ1(G4double lE);
92 G4double HighEnergyJ2(G4double lE);
93 G4double HighEnergyJ3(G4double lE);
94 G4double SolveTheEquation(G4double f);
95 G4double Fun(G4double x);
96 G4double DFun(G4double x);
97
98// Body
99private:
100 static G4int lastN; // The last N of calculated nucleus
101 static G4int lastZ; // The last Z of calculated nucleus
102 static G4int lastF; // Last used in the cross section TheFirstBin
103 static G4double* lastJ1; // Pointer to the last array of the J1 function
104 static G4double* lastJ2; // Pointer to the last array of the J2 function
105 static G4double* lastJ3; // Pointer to the last array of the J3 function
106 static G4int lastL; // Last used in the cross section TheLastBin
107 static G4double lastE; // Last used in the cross section Energy
108 static G4double lastTH; // Last value of the Energy Threshold
109 static G4double lastSig; // Last value of the Cross Section
110 static G4double lastG; // Last value of gamma=lnE-ln(me)
111 static G4double lastH; // Last value of the High energy A-dependence
112
113 static std::vector <G4double*> J1; // Vector of pointers to the J1 tabulated functions
114 static std::vector <G4double*> J2; // Vector of pointers to the J2 tabulated functions
115 static std::vector <G4double*> J3; // Vector of pointers to the J3 tabulated functions
116};
117
118inline G4double G4ElectroNuclearCrossSection::DFun(G4double x)// Parametrization of the PhotoNucCS
119{
120 static const G4double shd=1.0734; // HE PomShadowing(D)
121 static const G4double poc=0.0375; // HE Pomeron coefficient
122 static const G4double pos=16.5; // HE Pomeron shift
123 static const G4double reg=.11; // HE Reggeon slope
124 static const G4double mel=0.5109989; // Mass of an electron in MeV
125 static const G4double lmel=std::log(mel); // Log of an electron mass
126 G4double y=std::exp(x-lastG-lmel); // y for the x
127 G4double flux=lastG*(2.-y*(2.-y))-1.; // flux factor
128 return (poc*(x-pos)+shd*std::exp(-reg*x))*flux;
129}
130
131inline G4double G4ElectroNuclearCrossSection::Fun(G4double x) // Integrated PhoNuc cross section
132{
133 G4double dlg1=lastG+lastG-1.;
134 G4double lgoe=lastG/lastE;
135 G4double HE2=HighEnergyJ2(x);
136 return dlg1*HighEnergyJ1(x)-lgoe*(HE2+HE2-HighEnergyJ3(x)/lastE);
137}
138
139inline G4double G4ElectroNuclearCrossSection::HighEnergyJ1(G4double lEn)
140{
141 static const G4double le=std::log(50000.); // std::log(E0)
142 static const G4double le2=le*le; // std::log(E0)^2
143 static const G4double a=.0375; // a
144 static const G4double ha=a*.5; // a/2
145 static const G4double ab=a*16.5; // a*b
146 static const G4double d=0.11; // d
147 static const G4double cd=1.0734/d; // c/d
148 static const G4double ele=std::exp(-d*le); // E0^(-d)
149 return ha*(lEn*lEn-le2)-ab*(lEn-le)-cd*(std::exp(-d*lEn)-ele);
150}
151
152inline G4double G4ElectroNuclearCrossSection::HighEnergyJ2(G4double lEn)
153{
154 static const G4double e=50000.; // E0
155 static const G4double le=std::log(e); // std::log(E0)
156 static const G4double le1=(le-1.)*e; // (std::log(E0)-1)*E0
157 static const G4double a=.0375; // a
158 static const G4double ab=a*16.5; // a*b
159 static const G4double d=1.-0.11; // 1-d
160 static const G4double cd=1.0734/d; // c/(1-d)
161 static const G4double ele=std::exp(d*le); // E0^(1-d)
162 G4double En=std::exp(lEn);
163 return a*((lEn-1.)*En-le1)-ab*(En-e)+cd*(std::exp(d*lEn)-ele);
164}
165
166inline G4double G4ElectroNuclearCrossSection::HighEnergyJ3(G4double lEn)
167{
168 static const G4double e=50000.; // E0
169 static const G4double le=std::log(e); // std::log(E0)
170 static const G4double e2=e*e; // E0^2
171 static const G4double leh=(le-.5)*e2; // (std::log(E0)-.5)*E0^2
172 static const G4double ha=.0375*.5; // a/2
173 static const G4double hab=ha*16.5; // a*b/2
174 static const G4double d=2.-.11; // 2-d
175 static const G4double cd=1.0734/d; // c/(2-d)
176 static const G4double ele=std::exp(d*le); // E0^(2-d)
177 G4double lastE2=std::exp(lEn+lEn);
178 return ha*((lEn-.5)*lastE2-leh)-hab*(lastE2-e2)+cd*(std::exp(d*lEn)-ele);
179}
180
181#endif
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