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26 // 26 //
27 // ------------------------------------------- 27 // -------------------------------------------------------------------
28 // 28 //
29 // GEANT4 Class file 29 // GEANT4 Class file
30 // 30 //
31 // 31 //
32 // File name: G4KleinNishinaCompton 32 // File name: G4KleinNishinaCompton
33 // 33 //
34 // Author: Vladimir Ivanchenko on base 34 // Author: Vladimir Ivanchenko on base of Michel Maire code
35 // 35 //
36 // Creation date: 15.03.2005 36 // Creation date: 15.03.2005
37 // 37 //
38 // Modifications: 38 // Modifications:
39 // 18-04-05 Use G4ParticleChangeForGamma (V.Iv 39 // 18-04-05 Use G4ParticleChangeForGamma (V.Ivantchenko)
40 // 27-03-06 Remove upper limit of cross sectio 40 // 27-03-06 Remove upper limit of cross section (V.Ivantchenko)
41 // 41 //
42 // Class Description: 42 // Class Description:
43 // 43 //
44 // ------------------------------------------- 44 // -------------------------------------------------------------------
45 // 45 //
46 //....oooOO0OOooo........oooOO0OOooo........oo 46 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
47 //....oooOO0OOooo........oooOO0OOooo........oo 47 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
48 48
49 #include "G4KleinNishinaCompton.hh" 49 #include "G4KleinNishinaCompton.hh"
50 #include "G4PhysicalConstants.hh" 50 #include "G4PhysicalConstants.hh"
51 #include "G4SystemOfUnits.hh" 51 #include "G4SystemOfUnits.hh"
52 #include "G4Electron.hh" 52 #include "G4Electron.hh"
53 #include "G4Gamma.hh" 53 #include "G4Gamma.hh"
54 #include "Randomize.hh" 54 #include "Randomize.hh"
55 #include "G4DataVector.hh" 55 #include "G4DataVector.hh"
56 #include "G4ParticleChangeForGamma.hh" 56 #include "G4ParticleChangeForGamma.hh"
57 #include "G4Log.hh" 57 #include "G4Log.hh"
58 #include "G4Exp.hh" 58 #include "G4Exp.hh"
59 59
60 //....oooOO0OOooo........oooOO0OOooo........oo 60 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
61 61
62 using namespace std; 62 using namespace std;
63 63
64 G4KleinNishinaCompton::G4KleinNishinaCompton(c 64 G4KleinNishinaCompton::G4KleinNishinaCompton(const G4ParticleDefinition*,
65 c 65 const G4String& nam)
66 : G4VEmModel(nam) 66 : G4VEmModel(nam)
67 { 67 {
68 theGamma = G4Gamma::Gamma(); 68 theGamma = G4Gamma::Gamma();
69 theElectron = G4Electron::Electron(); 69 theElectron = G4Electron::Electron();
70 lowestSecondaryEnergy = 100.0*eV; 70 lowestSecondaryEnergy = 100.0*eV;
71 fParticleChange = nullptr; 71 fParticleChange = nullptr;
72 } 72 }
73 73
74 //....oooOO0OOooo........oooOO0OOooo........oo 74 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
75 75
76 G4KleinNishinaCompton::~G4KleinNishinaCompton( << 76 G4KleinNishinaCompton::~G4KleinNishinaCompton()
>> 77 {}
77 78
78 //....oooOO0OOooo........oooOO0OOooo........oo 79 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
79 80
80 void G4KleinNishinaCompton::Initialise(const G 81 void G4KleinNishinaCompton::Initialise(const G4ParticleDefinition* p,
81 const G 82 const G4DataVector& cuts)
82 { 83 {
83 if(IsMaster()) { InitialiseElementSelectors( 84 if(IsMaster()) { InitialiseElementSelectors(p, cuts); }
84 if(nullptr == fParticleChange) { 85 if(nullptr == fParticleChange) {
85 fParticleChange = GetParticleChangeForGamm 86 fParticleChange = GetParticleChangeForGamma();
86 } 87 }
87 } 88 }
88 89
89 //....oooOO0OOooo........oooOO0OOooo........oo 90 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
90 91
91 void G4KleinNishinaCompton::InitialiseLocal(co 92 void G4KleinNishinaCompton::InitialiseLocal(const G4ParticleDefinition*,
92 G4 93 G4VEmModel* masterModel)
93 { 94 {
94 SetElementSelectors(masterModel->GetElementS 95 SetElementSelectors(masterModel->GetElementSelectors());
95 } 96 }
96 97
97 //....oooOO0OOooo........oooOO0OOooo........oo 98 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
98 99
99 G4double G4KleinNishinaCompton::ComputeCrossSe 100 G4double G4KleinNishinaCompton::ComputeCrossSectionPerAtom(
100 const G 101 const G4ParticleDefinition*,
101 G 102 G4double GammaEnergy,
102 G 103 G4double Z, G4double,
103 G 104 G4double, G4double)
104 { 105 {
105 G4double xSection = 0.0 ; 106 G4double xSection = 0.0 ;
106 if (GammaEnergy <= LowEnergyLimit()) { retur 107 if (GammaEnergy <= LowEnergyLimit()) { return xSection; }
107 108
108 static const G4double a = 20.0 , b = 230.0 , 109 static const G4double a = 20.0 , b = 230.0 , c = 440.0;
109 110
110 static const G4double 111 static const G4double
111 d1= 2.7965e-1*CLHEP::barn, d2=-1.8300e-1*CLH 112 d1= 2.7965e-1*CLHEP::barn, d2=-1.8300e-1*CLHEP::barn,
112 d3= 6.7527 *CLHEP::barn, d4=-1.9798e+1*CLH 113 d3= 6.7527 *CLHEP::barn, d4=-1.9798e+1*CLHEP::barn,
113 e1= 1.9756e-5*CLHEP::barn, e2=-1.0205e-2*CLH 114 e1= 1.9756e-5*CLHEP::barn, e2=-1.0205e-2*CLHEP::barn,
114 e3=-7.3913e-2*CLHEP::barn, e4= 2.7079e-2*CLH 115 e3=-7.3913e-2*CLHEP::barn, e4= 2.7079e-2*CLHEP::barn,
115 f1=-3.9178e-7*CLHEP::barn, f2= 6.8241e-5*CLH 116 f1=-3.9178e-7*CLHEP::barn, f2= 6.8241e-5*CLHEP::barn,
116 f3= 6.0480e-5*CLHEP::barn, f4= 3.0274e-4*CLH 117 f3= 6.0480e-5*CLHEP::barn, f4= 3.0274e-4*CLHEP::barn;
117 118
118 G4double p1Z = Z*(d1 + e1*Z + f1*Z*Z), p2Z = 119 G4double p1Z = Z*(d1 + e1*Z + f1*Z*Z), p2Z = Z*(d2 + e2*Z + f2*Z*Z),
119 p3Z = Z*(d3 + e3*Z + f3*Z*Z), p4Z = 120 p3Z = Z*(d3 + e3*Z + f3*Z*Z), p4Z = Z*(d4 + e4*Z + f4*Z*Z);
120 121
121 G4double T0 = 15.0*keV; 122 G4double T0 = 15.0*keV;
122 if (Z < 1.5) { T0 = 40.0*keV; } 123 if (Z < 1.5) { T0 = 40.0*keV; }
123 124
124 G4double X = max(GammaEnergy, T0) / electr 125 G4double X = max(GammaEnergy, T0) / electron_mass_c2;
125 xSection = p1Z*G4Log(1.+2.*X)/X 126 xSection = p1Z*G4Log(1.+2.*X)/X
126 + (p2Z + p3Z*X + p4Z*X*X)/(1. + 127 + (p2Z + p3Z*X + p4Z*X*X)/(1. + a*X + b*X*X + c*X*X*X);
127 128
128 // modification for low energy. (special ca 129 // modification for low energy. (special case for Hydrogen)
129 if (GammaEnergy < T0) { 130 if (GammaEnergy < T0) {
130 static const G4double dT0 = keV; 131 static const G4double dT0 = keV;
131 X = (T0+dT0) / electron_mass_c2 ; 132 X = (T0+dT0) / electron_mass_c2 ;
132 G4double sigma = p1Z*G4Log(1.+2*X)/X 133 G4double sigma = p1Z*G4Log(1.+2*X)/X
133 + (p2Z + p3Z*X + p4Z*X*X)/ 134 + (p2Z + p3Z*X + p4Z*X*X)/(1. + a*X + b*X*X + c*X*X*X);
134 G4double c1 = -T0*(sigma-xSection)/(xSec 135 G4double c1 = -T0*(sigma-xSection)/(xSection*dT0);
135 G4double c2 = 0.150; 136 G4double c2 = 0.150;
136 if (Z > 1.5) { c2 = 0.375-0.0556*G4Log(Z); 137 if (Z > 1.5) { c2 = 0.375-0.0556*G4Log(Z); }
137 G4double y = G4Log(GammaEnergy/T0); 138 G4double y = G4Log(GammaEnergy/T0);
138 xSection *= G4Exp(-y*(c1+c2*y)); 139 xSection *= G4Exp(-y*(c1+c2*y));
139 } 140 }
140 // G4cout<<"e= "<< GammaEnergy<<" Z= "<<Z<<" 141 // G4cout<<"e= "<< GammaEnergy<<" Z= "<<Z<<" cross= " << xSection << G4endl;
141 return xSection; 142 return xSection;
142 } 143 }
143 144
144 //....oooOO0OOooo........oooOO0OOooo........oo 145 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
145 146
146 void G4KleinNishinaCompton::SampleSecondaries( 147 void G4KleinNishinaCompton::SampleSecondaries(
147 std::vector<G4Dyna 148 std::vector<G4DynamicParticle*>* fvect,
148 const G4MaterialCu 149 const G4MaterialCutsCouple*,
149 const G4DynamicPar 150 const G4DynamicParticle* aDynamicGamma,
150 G4double, 151 G4double,
151 G4double) 152 G4double)
152 { 153 {
153 // The scattered gamma energy is sampled acc 154 // The scattered gamma energy is sampled according to Klein - Nishina formula.
154 // The random number techniques of Butcher & 155 // The random number techniques of Butcher & Messel are used
155 // (Nuc Phys 20(1960),15). 156 // (Nuc Phys 20(1960),15).
156 // Note : Effects due to binding of atomic e 157 // Note : Effects due to binding of atomic electrons are negliged.
157 158
158 G4double gamEnergy0 = aDynamicGamma->GetKine 159 G4double gamEnergy0 = aDynamicGamma->GetKineticEnergy();
159 160
160 // do nothing below the threshold 161 // do nothing below the threshold
161 if(gamEnergy0 <= LowEnergyLimit()) { return; 162 if(gamEnergy0 <= LowEnergyLimit()) { return; }
162 163
163 G4double E0_m = gamEnergy0 / electron_mass_c 164 G4double E0_m = gamEnergy0 / electron_mass_c2 ;
164 165
165 G4ThreeVector gamDirection0 = aDynamicGamma- 166 G4ThreeVector gamDirection0 = aDynamicGamma->GetMomentumDirection();
166 167
167 // 168 //
168 // sample the energy rate of the scattered g 169 // sample the energy rate of the scattered gamma
169 // 170 //
170 171
171 G4double epsilon, epsilonsq, onecost, sint2, 172 G4double epsilon, epsilonsq, onecost, sint2, greject ;
172 173
173 G4double eps0 = 1./(1. + 2.*E0_m); 174 G4double eps0 = 1./(1. + 2.*E0_m);
174 G4double epsilon0sq = eps0*eps0; 175 G4double epsilon0sq = eps0*eps0;
175 G4double alpha1 = - G4Log(eps0); 176 G4double alpha1 = - G4Log(eps0);
176 G4double alpha2 = alpha1 + 0.5*(1.- epsi 177 G4double alpha2 = alpha1 + 0.5*(1.- epsilon0sq);
177 178
178 CLHEP::HepRandomEngine* rndmEngineMod = G4Ra 179 CLHEP::HepRandomEngine* rndmEngineMod = G4Random::getTheEngine();
179 G4double rndm[3]; 180 G4double rndm[3];
180 181
181 static const G4int nlooplim = 1000; 182 static const G4int nlooplim = 1000;
182 G4int nloop = 0; 183 G4int nloop = 0;
183 do { 184 do {
184 ++nloop; 185 ++nloop;
185 // false interaction if too many iteration 186 // false interaction if too many iterations
186 if(nloop > nlooplim) { return; } 187 if(nloop > nlooplim) { return; }
187 188
188 // 3 random numbers to sample scattering 189 // 3 random numbers to sample scattering
189 rndmEngineMod->flatArray(3, rndm); 190 rndmEngineMod->flatArray(3, rndm);
190 191
191 if ( alpha1 > alpha2*rndm[0] ) { 192 if ( alpha1 > alpha2*rndm[0] ) {
192 epsilon = G4Exp(-alpha1*rndm[1]); // 193 epsilon = G4Exp(-alpha1*rndm[1]); // eps0**r
193 epsilonsq = epsilon*epsilon; 194 epsilonsq = epsilon*epsilon;
194 195
195 } else { 196 } else {
196 epsilonsq = epsilon0sq + (1.- epsilon0sq 197 epsilonsq = epsilon0sq + (1.- epsilon0sq)*rndm[1];
197 epsilon = sqrt(epsilonsq); 198 epsilon = sqrt(epsilonsq);
198 }; 199 };
199 200
200 onecost = (1.- epsilon)/(epsilon*E0_m); 201 onecost = (1.- epsilon)/(epsilon*E0_m);
201 sint2 = onecost*(2.-onecost); 202 sint2 = onecost*(2.-onecost);
202 greject = 1. - epsilon*sint2/(1.+ epsilons 203 greject = 1. - epsilon*sint2/(1.+ epsilonsq);
203 204
204 // Loop checking, 03-Aug-2015, Vladimir Iv 205 // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
205 } while (greject < rndm[2]); 206 } while (greject < rndm[2]);
206 207
207 // 208 //
208 // scattered gamma angles. ( Z - axis along 209 // scattered gamma angles. ( Z - axis along the parent gamma)
209 // 210 //
210 211
211 if(sint2 < 0.0) { sint2 = 0.0; } 212 if(sint2 < 0.0) { sint2 = 0.0; }
212 G4double cosTeta = 1. - onecost; 213 G4double cosTeta = 1. - onecost;
213 G4double sinTeta = sqrt (sint2); 214 G4double sinTeta = sqrt (sint2);
214 G4double Phi = twopi * rndmEngineMod->fl 215 G4double Phi = twopi * rndmEngineMod->flat();
215 216
216 // 217 //
217 // update G4VParticleChange for the scattere 218 // update G4VParticleChange for the scattered gamma
218 // 219 //
219 220
220 G4ThreeVector gamDirection1(sinTeta*cos(Phi) 221 G4ThreeVector gamDirection1(sinTeta*cos(Phi), sinTeta*sin(Phi), cosTeta);
221 gamDirection1.rotateUz(gamDirection0); 222 gamDirection1.rotateUz(gamDirection0);
222 G4double gamEnergy1 = epsilon*gamEnergy0; 223 G4double gamEnergy1 = epsilon*gamEnergy0;
223 G4double edep = 0.0; 224 G4double edep = 0.0;
224 if(gamEnergy1 > lowestSecondaryEnergy) { 225 if(gamEnergy1 > lowestSecondaryEnergy) {
225 fParticleChange->ProposeMomentumDirection( 226 fParticleChange->ProposeMomentumDirection(gamDirection1);
226 fParticleChange->SetProposedKineticEnergy( 227 fParticleChange->SetProposedKineticEnergy(gamEnergy1);
227 } else { 228 } else {
228 fParticleChange->ProposeTrackStatus(fStopA 229 fParticleChange->ProposeTrackStatus(fStopAndKill);
229 fParticleChange->SetProposedKineticEnergy( 230 fParticleChange->SetProposedKineticEnergy(0.0);
230 edep = gamEnergy1; 231 edep = gamEnergy1;
231 } 232 }
232 233
233 // 234 //
234 // kinematic of the scattered electron 235 // kinematic of the scattered electron
235 // 236 //
236 237
237 G4double eKinEnergy = gamEnergy0 - gamEnergy 238 G4double eKinEnergy = gamEnergy0 - gamEnergy1;
238 239
239 if(eKinEnergy > lowestSecondaryEnergy) { 240 if(eKinEnergy > lowestSecondaryEnergy) {
240 G4ThreeVector eDirection = gamEnergy0*gamD 241 G4ThreeVector eDirection = gamEnergy0*gamDirection0 - gamEnergy1*gamDirection1;
241 eDirection = eDirection.unit(); 242 eDirection = eDirection.unit();
242 243
243 // create G4DynamicParticle object for the 244 // create G4DynamicParticle object for the electron.
244 auto dp = new G4DynamicParticle(theElectro << 245 G4DynamicParticle* dp = new G4DynamicParticle(theElectron,eDirection,eKinEnergy);
245 fvect->push_back(dp); 246 fvect->push_back(dp);
246 } else { 247 } else {
247 edep += eKinEnergy; 248 edep += eKinEnergy;
248 } 249 }
249 // energy balance 250 // energy balance
250 if(edep > 0.0) { 251 if(edep > 0.0) {
251 fParticleChange->ProposeLocalEnergyDeposit 252 fParticleChange->ProposeLocalEnergyDeposit(edep);
252 } 253 }
253 } 254 }
254 255
255 //....oooOO0OOooo........oooOO0OOooo........oo 256 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
256 257
257 258
258 259