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26 /// \file medical/fanoCavity/src/MyKleinNishin << 26 // $Id: MyKleinNishinaCompton.cc,v 1.5 2007/10/01 15:19:57 maire Exp $
27 /// \brief Implementation of the MyKleinNishin << 27 // GEANT4 tag $Name: geant4-09-02-patch-04 $
28 // <<
29 // 28 //
30 //....oooOO0OOooo........oooOO0OOooo........oo 29 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
31 //....oooOO0OOooo........oooOO0OOooo........oo 30 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
32 31
33 #include "MyKleinNishinaCompton.hh" 32 #include "MyKleinNishinaCompton.hh"
34 <<
35 #include "DetectorConstruction.hh" 33 #include "DetectorConstruction.hh"
36 #include "MyKleinNishinaMessenger.hh" <<
37 34
38 #include "G4DataVector.hh" <<
39 #include "G4Electron.hh" 35 #include "G4Electron.hh"
40 #include "G4Gamma.hh" 36 #include "G4Gamma.hh"
41 #include "G4ParticleChangeForGamma.hh" <<
42 #include "G4PhysicalConstants.hh" <<
43 #include "Randomize.hh" 37 #include "Randomize.hh"
>> 38 #include "G4DataVector.hh"
>> 39 #include "G4ParticleChangeForGamma.hh"
44 40
45 //....oooOO0OOooo........oooOO0OOooo........oo 41 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
46 42
47 using namespace std; 43 using namespace std;
48 44
49 MyKleinNishinaCompton::MyKleinNishinaCompton(D << 45 MyKleinNishinaCompton::MyKleinNishinaCompton(DetectorConstruction* det,
>> 46 const G4ParticleDefinition*,
50 c 47 const G4String& nam)
51 : G4KleinNishinaCompton(0, nam), fDetector(d << 48 :G4KleinNishinaCompton(0,nam), detector(det)
52 { 49 {
53 fCrossSectionFactor = 1.; << 50 CrossSectionFactor = 1.;
54 fMessenger = new MyKleinNishinaMessenger(thi <<
55 } 51 }
56 52
57 //....oooOO0OOooo........oooOO0OOooo........oo 53 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
58 54
59 MyKleinNishinaCompton::~MyKleinNishinaCompton( 55 MyKleinNishinaCompton::~MyKleinNishinaCompton()
60 { << 56 {}
61 delete fMessenger; <<
62 } <<
63 57
64 //....oooOO0OOooo........oooOO0OOooo........oo 58 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
65 59
66 G4double MyKleinNishinaCompton::CrossSectionPe << 60 G4double MyKleinNishinaCompton::CrossSectionPerVolume(
67 << 61 const G4Material* mat,
68 << 62 const G4ParticleDefinition* part,
>> 63 G4double GammaEnergy,
>> 64 G4double, G4double)
69 { 65 {
70 G4double xsection = G4VEmModel::CrossSection << 66 G4double CrossSection =
>> 67 G4VEmModel::CrossSectionPerVolume(mat,part,GammaEnergy);
71 68
72 return xsection * fCrossSectionFactor; << 69 return CrossSection*CrossSectionFactor;
73 } 70 }
74 //....oooOO0OOooo........oooOO0OOooo........oo 71 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
75 72
76 void MyKleinNishinaCompton::SampleSecondaries( << 73 void MyKleinNishinaCompton::SampleSecondaries(
77 << 74 std::vector<G4DynamicParticle*>* fvect,
78 << 75 const G4MaterialCutsCouple*,
79 << 76 const G4DynamicParticle* aDynamicGamma,
>> 77 G4double,
>> 78 G4double)
80 { 79 {
81 // The scattered gamma energy is sampled acc 80 // The scattered gamma energy is sampled according to Klein - Nishina formula.
82 // The random number techniques of Butcher & << 81 // The random number techniques of Butcher & Messel are used
83 // (Nuc Phys 20(1960),15). 82 // (Nuc Phys 20(1960),15).
84 // Note : Effects due to binding of atomic e 83 // Note : Effects due to binding of atomic electrons are negliged.
85 << 84
86 G4double gamEnergy0 = aDynamicGamma->GetKine 85 G4double gamEnergy0 = aDynamicGamma->GetKineticEnergy();
87 G4double E0_m = gamEnergy0 / electron_mass_c << 86 G4double E0_m = gamEnergy0 / electron_mass_c2 ;
88 87
89 G4ThreeVector gamDirection0 = aDynamicGamma- 88 G4ThreeVector gamDirection0 = aDynamicGamma->GetMomentumDirection();
90 89
91 // 90 //
92 // sample the energy rate of the scattered g << 91 // sample the energy rate of the scattered gamma
93 // 92 //
94 93
95 G4double epsilon, epsilonsq, onecost, sint2, << 94 G4double epsilon, epsilonsq, onecost, sint2, greject ;
96 95
97 G4double eps0 = 1. / (1. + 2. * E0_m); << 96 G4double epsilon0 = 1./(1. + 2.*E0_m);
98 G4double eps0sq = eps0 * eps0; << 97 G4double epsilon0sq = epsilon0*epsilon0;
99 G4double alpha1 = -log(eps0); << 98 G4double alpha1 = - log(epsilon0);
100 G4double alpha2 = 0.5 * (1. - eps0sq); << 99 G4double alpha2 = 0.5*(1.- epsilon0sq);
101 100
102 do { 101 do {
103 if (alpha1 / (alpha1 + alpha2) > G4Uniform << 102 if ( alpha1/(alpha1+alpha2) > G4UniformRand() ) {
104 epsilon = exp(-alpha1 * G4UniformRand()) << 103 epsilon = exp(-alpha1*G4UniformRand()); // epsilon0**r
105 epsilonsq = epsilon * epsilon; << 104 epsilonsq = epsilon*epsilon;
106 } << 105
107 else { << 106 } else {
108 epsilonsq = eps0sq + (1. - eps0sq) * G4U << 107 epsilonsq = epsilon0sq + (1.- epsilon0sq)*G4UniformRand();
109 epsilon = sqrt(epsilonsq); << 108 epsilon = sqrt(epsilonsq);
110 }; 109 };
111 110
112 onecost = (1. - epsilon) / (epsilon * E0_m << 111 onecost = (1.- epsilon)/(epsilon*E0_m);
113 sint2 = onecost * (2. - onecost); << 112 sint2 = onecost*(2.-onecost);
114 greject = 1. - epsilon * sint2 / (1. + eps << 113 greject = 1. - epsilon*sint2/(1.+ epsilonsq);
115 114
116 } while (greject < G4UniformRand()); 115 } while (greject < G4UniformRand());
117 << 116
118 // 117 //
119 // scattered gamma angles. ( Z - axis along 118 // scattered gamma angles. ( Z - axis along the parent gamma)
120 // 119 //
121 120
122 G4double cosTeta = 1. - onecost; << 121 G4double cosTeta = 1. - onecost;
123 G4double sinTeta = sqrt(sint2); << 122 G4double sinTeta = sqrt (sint2);
124 G4double Phi = twopi * G4UniformRand(); << 123 G4double Phi = twopi * G4UniformRand();
125 G4double dirx = sinTeta * cos(Phi), diry = s << 124 G4double dirx = sinTeta*cos(Phi), diry = sinTeta*sin(Phi), dirz = cosTeta;
126 125
127 // 126 //
128 // update G4VParticleChange for the scattere 127 // update G4VParticleChange for the scattered gamma
129 // 128 //
130 // beam regeneration trick : restore inciden 129 // beam regeneration trick : restore incident beam
131 << 130
132 G4ThreeVector gamDirection1(dirx, diry, dirz << 131 G4ThreeVector gamDirection1 ( dirx,diry,dirz );
133 gamDirection1.rotateUz(gamDirection0); 132 gamDirection1.rotateUz(gamDirection0);
134 G4double gamEnergy1 = epsilon * gamEnergy0; << 133 G4double gamEnergy1 = epsilon*gamEnergy0;
135 fParticleChange->SetProposedKineticEnergy(ga 134 fParticleChange->SetProposedKineticEnergy(gamEnergy0);
136 fParticleChange->ProposeMomentumDirection(ga 135 fParticleChange->ProposeMomentumDirection(gamDirection0);
137 136
138 // 137 //
139 // kinematic of the scattered electron 138 // kinematic of the scattered electron
140 // 139 //
141 140
142 G4double eKinEnergy = gamEnergy0 - gamEnergy 141 G4double eKinEnergy = gamEnergy0 - gamEnergy1;
143 142
144 if (eKinEnergy > DBL_MIN) { << 143 if(eKinEnergy > DBL_MIN) {
145 G4ThreeVector eDirection = gamEnergy0 * ga << 144 G4ThreeVector eDirection
>> 145 = gamEnergy0*gamDirection0 - gamEnergy1*gamDirection1;
146 eDirection = eDirection.unit(); 146 eDirection = eDirection.unit();
147 147
148 // create G4DynamicParticle object for the 148 // create G4DynamicParticle object for the electron.
149 G4DynamicParticle* dp = new G4DynamicParti << 149 G4DynamicParticle* dp
>> 150 = new G4DynamicParticle(theElectron,eDirection,eKinEnergy);
150 fvect->push_back(dp); 151 fvect->push_back(dp);
151 } 152 }
152 } 153 }
153 154
154 //....oooOO0OOooo........oooOO0OOooo........oo 155 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 156
>> 157
155 158