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25 // 25 //
26 // G4RToEConvForGamma class implementation <<
27 // 26 //
28 // Author: H.Kurashige, 05 October 2002 - Firs << 27 // $Id: G4RToEConvForGamma.cc,v 1.6 2009-09-12 12:09:42 kurasige Exp $
29 // ------------------------------------------- << 28 // GEANT4 tag $Name: not supported by cvs2svn $
>> 29 //
>> 30 //
>> 31 // --------------------------------------------------------------
>> 32 // GEANT 4 class implementation file/ History:
>> 33 // 5 Oct. 2002, H.Kuirashige : Structure created based on object model
>> 34 // --------------------------------------------------------------
30 35
31 #include "G4RToEConvForGamma.hh" 36 #include "G4RToEConvForGamma.hh"
32 #include "G4ParticleDefinition.hh" 37 #include "G4ParticleDefinition.hh"
33 #include "G4ParticleTable.hh" 38 #include "G4ParticleTable.hh"
34 #include "G4SystemOfUnits.hh" << 39 #include "G4Material.hh"
35 #include "G4Log.hh" << 40 #include "G4PhysicsLogVector.hh"
36 #include "G4Exp.hh" << 41
37 #include "G4Pow.hh" << 42 #include "G4ios.hh"
38 << 43
39 // ------------------------------------------- << 44 G4RToEConvForGamma::G4RToEConvForGamma() : G4VRangeToEnergyConverter()
40 G4RToEConvForGamma::G4RToEConvForGamma() <<
41 : G4VRangeToEnergyConverter() <<
42 { 45 {
43 theParticle = G4ParticleTable::GetParticleTa << 46 theParticle = G4ParticleTable::GetParticleTable()->FindParticle("gamma");
44 if (theParticle == nullptr) << 47 if (theParticle ==0) {
45 { <<
46 #ifdef G4VERBOSE 48 #ifdef G4VERBOSE
47 if (GetVerboseLevel()>0) << 49 if (GetVerboseLevel()>0) {
48 { << 50 G4cout << " G4RToEConvForGamma::G4RToEConvForGamma() ";
49 G4cout << " G4RToEConvForGamma::G4RToECo << 51 G4cout << " Gamma is not defined !!" << G4endl;
50 G4cout << "Gamma is not defined !!" << G <<
51 } 52 }
52 #endif 53 #endif
53 } 54 }
54 else <<
55 { <<
56 fPDG = theParticle->GetPDGEncoding(); <<
57 } <<
58 } 55 }
59 56
60 // ------------------------------------------- << 57 G4RToEConvForGamma::~G4RToEConvForGamma()
61 G4RToEConvForGamma::~G4RToEConvForGamma() << 58 {
62 {} << 59 }
63 << 60
64 // ------------------------------------------- << 61
65 G4double G4RToEConvForGamma::ComputeValue(cons << 62 // ***********************************************************************
66 cons << 63 // ******************* BuildAbsorptionLengthVector ***********************
>> 64 // ***********************************************************************
>> 65 void G4RToEConvForGamma::BuildAbsorptionLengthVector(
>> 66 const G4Material* aMaterial,
>> 67 G4RangeVector* absorptionLengthVector )
67 { 68 {
68 // Compute the "absorption" cross-section of << 69 // fill the absorption length vector for this material
69 // Cross-section means here the sum of the c << 70 // absorption length is defined here as
70 // pair production, Compton scattering and p << 71 //
71 << 72 // absorption length = 5./ macroscopic absorption cross section
72 const G4double t1keV = 1.*CLHEP::keV; << 73 //
73 const G4double t200keV = 200.*CLHEP::keV; << 74 const G4CrossSectionTable* aCrossSectionTable = (G4CrossSectionTable*)(theLossTable);
74 const G4double t100MeV = 100.*CLHEP::MeV; << 75 const G4ElementVector* elementVector = aMaterial->GetElementVector();
75 << 76 const G4double* atomicNumDensityVector = aMaterial->GetAtomicNumDensityVector();
76 G4double Zsquare = Z*Z; << 77
77 G4double Zlog = G4Pow::GetInstance()->logZ(Z << 78 // fill absorption length vector
78 G4double Zlogsquare = Zlog*Zlog; << 79 G4int NumEl = aMaterial->GetNumberOfElements();
79 << 80 G4double absorptionLengthMax = 0.0;
80 G4double tmin = (0.552+218.5/Z+557.17/Zsquar << 81 for (size_t ibin=0; ibin<size_t(TotBin); ibin++) {
81 G4double tlow = 0.2*G4Exp(-7.355/std::sqrt(Z << 82 G4double SIGMA = 0. ;
82 << 83 for (size_t iel=0; iel<size_t(NumEl); iel++) {
83 G4double smin = (0.01239+0.005585*Zlog-0.000 << 84 G4int IndEl = (*elementVector)[iel]->GetIndex();
84 G4double s200keV = (0.2651-0.1501*Zlog+0.022 << 85 SIGMA += atomicNumDensityVector[iel]*
85 << 86 (*((*aCrossSectionTable)[IndEl]))[ibin];
86 G4double cminlog = G4Log(tmin/t200keV); << 87 }
87 G4double cmin = G4Log(s200keV/smin)/(cminlog << 88 // absorption length=5./SIGMA
88 << 89 absorptionLengthVector->PutValue(ibin, 5./SIGMA);
89 G4double slowlog = G4Log(t200keV/tlow); << 90 if (absorptionLengthMax < 5./SIGMA ) absorptionLengthMax = 5./SIGMA;
90 G4double slow = s200keV * G4Exp(0.042*Z*slow <<
91 G4double logtlow = G4Log(tlow/t1keV); <<
92 G4double clow = G4Log(300.*Zsquare/slow)/log <<
93 G4double chigh = (7.55e-5 - 0.0542e-5*Z)*Zsq <<
94 <<
95 // Calculate the cross-section (using an app <<
96 G4double xs; <<
97 if ( energy < tlow ) <<
98 { <<
99 xs = (energy < t1keV) ? slow*G4Exp(clow*lo <<
100 slow*G4Exp(clow*G4Log(tlow/energy)); <<
101 } <<
102 else if ( energy < t200keV ) <<
103 { <<
104 G4double x = G4Log(t200keV/energy); <<
105 xs = s200keV * G4Exp(0.042*Z*x*x); <<
106 } 91 }
107 else if( energy<tmin ) << 92 }
108 { << 93
109 const G4double x = G4Log(tmin/energy); << 94
110 xs = smin * G4Exp(cmin*x*x); << 95
>> 96 // ***********************************************************************
>> 97 // ********************** ComputeCrossSection ****************************
>> 98 // ***********************************************************************
>> 99 G4double G4RToEConvForGamma::ComputeCrossSection(G4double AtomicNumber,
>> 100 G4double KineticEnergy) const
>> 101 {
>> 102 // Compute the "absorption" cross section of the photon "absorption"
>> 103 // cross section means here the sum of the cross sections of the
>> 104 // pair production, Compton scattering and photoelectric processes
>> 105 static G4double Z;
>> 106 const G4double t1keV = 1.*keV;
>> 107 const G4double t200keV = 200.*keV;
>> 108 const G4double t100MeV = 100.*MeV;
>> 109
>> 110 static G4double s200keV, s1keV;
>> 111 static G4double tmin, tlow;
>> 112 static G4double smin, slow;
>> 113 static G4double cmin, clow, chigh;
>> 114 // compute Z dependent quantities in the case of a new AtomicNumber
>> 115 if(std::abs(AtomicNumber-Z)>0.1) {
>> 116 Z = AtomicNumber;
>> 117 G4double Zsquare = Z*Z;
>> 118 G4double Zlog = std::log(Z);
>> 119 G4double Zlogsquare = Zlog*Zlog;
>> 120
>> 121 s200keV = (0.2651-0.1501*Zlog+0.02283*Zlogsquare)*Zsquare;
>> 122 tmin = (0.552+218.5/Z+557.17/Zsquare)*MeV;
>> 123 smin = (0.01239+0.005585*Zlog-0.000923*Zlogsquare)*std::exp(1.5*Zlog);
>> 124 cmin=std::log(s200keV/smin)/(std::log(tmin/t200keV)*std::log(tmin/t200keV));
>> 125 tlow = 0.2*std::exp(-7.355/std::sqrt(Z))*MeV;
>> 126 slow = s200keV*std::exp(0.042*Z*std::log(t200keV/tlow)*std::log(t200keV/tlow));
>> 127 s1keV = 300.*Zsquare;
>> 128 clow =std::log(s1keV/slow)/std::log(tlow/t1keV);
>> 129
>> 130 chigh=(7.55e-5-0.0542e-5*Z)*Zsquare*Z/std::log(t100MeV/tmin);
111 } 131 }
112 else << 132
113 { << 133 // calculate the cross section (using an approximate empirical formula)
114 xs = smin + chigh*G4Log(energy/tmin); << 134 G4double s;
>> 135 if ( KineticEnergy<tlow ) {
>> 136 if(KineticEnergy<t1keV) s = slow*std::exp(clow*std::log(tlow/t1keV));
>> 137 else s = slow*std::exp(clow*std::log(tlow/KineticEnergy));
>> 138
>> 139 } else if ( KineticEnergy<t200keV ) {
>> 140 s = s200keV
>> 141 * std::exp(0.042*Z*std::log(t200keV/KineticEnergy)*std::log(t200keV/KineticEnergy));
>> 142
>> 143 } else if( KineticEnergy<tmin ){
>> 144 s = smin
>> 145 * std::exp(cmin*std::log(tmin/KineticEnergy)*std::log(tmin/KineticEnergy));
>> 146
>> 147 } else {
>> 148 s = smin + chigh*std::log(KineticEnergy/tmin);
>> 149
115 } 150 }
116 return xs * CLHEP::barn; << 151 return s * barn;
117 } 152 }
118 153
119 // ------------------------------------------- <<
120 154