| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
25 // 25 //
26 // 26 //
27 // ------------------------------------------- 27 // -------------------------------------------------------------------
28 // 28 //
29 // GEANT4 Class file 29 // GEANT4 Class file
30 // 30 //
31 // 31 //
32 // File name: G4BetheHeitlerModel 32 // File name: G4BetheHeitlerModel
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 by Vladimir Ivanchenko, Miche 38 // Modifications by Vladimir Ivanchenko, Michel Maire, Mihaly Novak
39 // 39 //
40 // Class Description: 40 // Class Description:
41 // 41 //
42 // ------------------------------------------- 42 // -------------------------------------------------------------------
43 // 43 //
44 44
45 #include "G4BetheHeitlerModel.hh" 45 #include "G4BetheHeitlerModel.hh"
46 #include "G4PhysicalConstants.hh" 46 #include "G4PhysicalConstants.hh"
47 #include "G4SystemOfUnits.hh" 47 #include "G4SystemOfUnits.hh"
48 #include "G4Electron.hh" 48 #include "G4Electron.hh"
49 #include "G4Positron.hh" 49 #include "G4Positron.hh"
50 #include "G4Gamma.hh" 50 #include "G4Gamma.hh"
51 #include "Randomize.hh" 51 #include "Randomize.hh"
52 #include "G4ParticleChangeForGamma.hh" 52 #include "G4ParticleChangeForGamma.hh"
53 #include "G4Pow.hh" 53 #include "G4Pow.hh"
54 #include "G4Exp.hh" 54 #include "G4Exp.hh"
55 #include "G4ModifiedTsai.hh" 55 #include "G4ModifiedTsai.hh"
56 #include "G4EmParameters.hh" <<
57 #include "G4EmElementXS.hh" <<
58 #include "G4AutoLock.hh" <<
59 56
60 const G4int G4BetheHeitlerModel::gMaxZet = 120 57 const G4int G4BetheHeitlerModel::gMaxZet = 120;
61 std::vector<G4BetheHeitlerModel::ElementData*> 58 std::vector<G4BetheHeitlerModel::ElementData*> G4BetheHeitlerModel::gElementData;
62 59
63 namespace <<
64 { <<
65 G4Mutex theBetheHMutex = G4MUTEX_INITIALIZER <<
66 } <<
67 <<
68 G4BetheHeitlerModel::G4BetheHeitlerModel(const 60 G4BetheHeitlerModel::G4BetheHeitlerModel(const G4ParticleDefinition*,
69 const 61 const G4String& nam)
70 : G4VEmModel(nam), 62 : G4VEmModel(nam),
71 fG4Calc(G4Pow::GetInstance()), fTheGamma(G4G 63 fG4Calc(G4Pow::GetInstance()), fTheGamma(G4Gamma::Gamma()),
72 fTheElectron(G4Electron::Electron()), fThePo 64 fTheElectron(G4Electron::Electron()), fThePositron(G4Positron::Positron()),
73 fParticleChange(nullptr) 65 fParticleChange(nullptr)
74 { 66 {
75 SetAngularDistribution(new G4ModifiedTsai()) 67 SetAngularDistribution(new G4ModifiedTsai());
76 } 68 }
77 69
78 G4BetheHeitlerModel::~G4BetheHeitlerModel() 70 G4BetheHeitlerModel::~G4BetheHeitlerModel()
79 { 71 {
80 if (isFirstInstance) { << 72 if (IsMaster()) {
81 for (auto const & ptr : gElementData) { de << 73 // clear ElementData container
>> 74 for (size_t iz = 0; iz < gElementData.size(); ++iz) {
>> 75 if (gElementData[iz]) delete gElementData[iz];
>> 76 }
82 gElementData.clear(); 77 gElementData.clear();
83 } 78 }
84 delete fXSection; <<
85 } 79 }
86 80
87 void G4BetheHeitlerModel::Initialise(const G4P 81 void G4BetheHeitlerModel::Initialise(const G4ParticleDefinition* p,
88 const G4D 82 const G4DataVector& cuts)
89 { 83 {
90 if (!fParticleChange) { fParticleChange = Ge << 84 if (IsMaster()) {
91 <<
92 if (isFirstInstance || gElementData.empty()) <<
93 G4AutoLock l(&theBetheHMutex); <<
94 if (gElementData.empty()) { <<
95 isFirstInstance = true; <<
96 gElementData.resize(gMaxZet+1, nullptr); <<
97 <<
98 // EPICS2017 flag should be checked only <<
99 useEPICS2017 = G4EmParameters::Instance( <<
100 if (useEPICS2017) { <<
101 fXSection = new G4EmElementXS(1, 100, "convE <<
102 } <<
103 } <<
104 // static data should be initialised only <<
105 InitialiseElementData(); 85 InitialiseElementData();
106 l.unlock(); <<
107 } 86 }
108 // element selectors should be initialised i << 87 if (!fParticleChange) { fParticleChange = GetParticleChangeForGamma(); }
109 if(IsMaster()) { << 88 if (IsMaster()) {
110 InitialiseElementSelectors(p, cuts); 89 InitialiseElementSelectors(p, cuts);
111 } 90 }
112 } 91 }
113 92
114 void G4BetheHeitlerModel::InitialiseLocal(cons 93 void G4BetheHeitlerModel::InitialiseLocal(const G4ParticleDefinition*,
115 G4VE 94 G4VEmModel* masterModel)
116 { 95 {
117 SetElementSelectors(masterModel->GetElementS 96 SetElementSelectors(masterModel->GetElementSelectors());
118 } 97 }
119 98
120 // Calculates the microscopic cross section in 99 // Calculates the microscopic cross section in GEANT4 internal units.
121 // A parametrized formula from L. Urban is use 100 // A parametrized formula from L. Urban is used to estimate
122 // the total cross section. 101 // the total cross section.
123 // It gives a good description of the data fro 102 // It gives a good description of the data from 1.5 MeV to 100 GeV.
124 // below 1.5 MeV: sigma=sigma(1.5MeV)*(GammaEn 103 // below 1.5 MeV: sigma=sigma(1.5MeV)*(GammaEnergy-2electronmass)
125 // *(GammaEn 104 // *(GammaEnergy-2electronmass)
126 G4double 105 G4double
127 G4BetheHeitlerModel::ComputeCrossSectionPerAto 106 G4BetheHeitlerModel::ComputeCrossSectionPerAtom(const G4ParticleDefinition*,
128 107 G4double gammaEnergy, G4double Z,
129 108 G4double, G4double, G4double)
130 { 109 {
131 G4double xSection = 0.0 ; 110 G4double xSection = 0.0 ;
132 // short versions 111 // short versions
133 static const G4double kMC2 = CLHEP::electro 112 static const G4double kMC2 = CLHEP::electron_mass_c2;
134 // zero cross section below the kinematical 113 // zero cross section below the kinematical limit: Eg<2mc^2
135 if (Z < 0.9 || gammaEnergy <= 2.0*kMC2) { re 114 if (Z < 0.9 || gammaEnergy <= 2.0*kMC2) { return xSection; }
136 <<
137 G4int iZ = G4lrint(Z); <<
138 if (useEPICS2017 && iZ < 101) { <<
139 return fXSection->GetXS(iZ, gammaEnergy); <<
140 } <<
141 <<
142 // 115 //
143 static const G4double gammaEnergyLimit = 1.5 116 static const G4double gammaEnergyLimit = 1.5*CLHEP::MeV;
144 // set coefficients a, b c 117 // set coefficients a, b c
145 static const G4double a0 = 8.7842e+2*CLHEP: 118 static const G4double a0 = 8.7842e+2*CLHEP::microbarn;
146 static const G4double a1 = -1.9625e+3*CLHEP: 119 static const G4double a1 = -1.9625e+3*CLHEP::microbarn;
147 static const G4double a2 = 1.2949e+3*CLHEP: 120 static const G4double a2 = 1.2949e+3*CLHEP::microbarn;
148 static const G4double a3 = -2.0028e+2*CLHEP: 121 static const G4double a3 = -2.0028e+2*CLHEP::microbarn;
149 static const G4double a4 = 1.2575e+1*CLHEP: 122 static const G4double a4 = 1.2575e+1*CLHEP::microbarn;
150 static const G4double a5 = -2.8333e-1*CLHEP: 123 static const G4double a5 = -2.8333e-1*CLHEP::microbarn;
151 124
152 static const G4double b0 = -1.0342e+1*CLHEP: 125 static const G4double b0 = -1.0342e+1*CLHEP::microbarn;
153 static const G4double b1 = 1.7692e+1*CLHEP: 126 static const G4double b1 = 1.7692e+1*CLHEP::microbarn;
154 static const G4double b2 = -8.2381 *CLHEP: 127 static const G4double b2 = -8.2381 *CLHEP::microbarn;
155 static const G4double b3 = 1.3063 *CLHEP: 128 static const G4double b3 = 1.3063 *CLHEP::microbarn;
156 static const G4double b4 = -9.0815e-2*CLHEP: 129 static const G4double b4 = -9.0815e-2*CLHEP::microbarn;
157 static const G4double b5 = 2.3586e-3*CLHEP: 130 static const G4double b5 = 2.3586e-3*CLHEP::microbarn;
158 131
159 static const G4double c0 = -4.5263e+2*CLHEP: 132 static const G4double c0 = -4.5263e+2*CLHEP::microbarn;
160 static const G4double c1 = 1.1161e+3*CLHEP: 133 static const G4double c1 = 1.1161e+3*CLHEP::microbarn;
161 static const G4double c2 = -8.6749e+2*CLHEP: 134 static const G4double c2 = -8.6749e+2*CLHEP::microbarn;
162 static const G4double c3 = 2.1773e+2*CLHEP: 135 static const G4double c3 = 2.1773e+2*CLHEP::microbarn;
163 static const G4double c4 = -2.0467e+1*CLHEP: 136 static const G4double c4 = -2.0467e+1*CLHEP::microbarn;
164 static const G4double c5 = 6.5372e-1*CLHEP: 137 static const G4double c5 = 6.5372e-1*CLHEP::microbarn;
165 // check low energy limit of the approximati 138 // check low energy limit of the approximation (1.5 MeV)
166 G4double gammaEnergyOrg = gammaEnergy; 139 G4double gammaEnergyOrg = gammaEnergy;
167 if (gammaEnergy < gammaEnergyLimit) { gammaE 140 if (gammaEnergy < gammaEnergyLimit) { gammaEnergy = gammaEnergyLimit; }
168 // compute gamma energy variables 141 // compute gamma energy variables
169 const G4double x = G4Log(gammaEnergy/kMC2); 142 const G4double x = G4Log(gammaEnergy/kMC2);
170 const G4double x2 = x *x; 143 const G4double x2 = x *x;
171 const G4double x3 = x2*x; 144 const G4double x3 = x2*x;
172 const G4double x4 = x3*x; 145 const G4double x4 = x3*x;
173 const G4double x5 = x4*x; 146 const G4double x5 = x4*x;
174 // 147 //
175 const G4double F1 = a0 + a1*x + a2*x2 + a3*x 148 const G4double F1 = a0 + a1*x + a2*x2 + a3*x3 + a4*x4 + a5*x5;
176 const G4double F2 = b0 + b1*x + b2*x2 + b3*x 149 const G4double F2 = b0 + b1*x + b2*x2 + b3*x3 + b4*x4 + b5*x5;
177 const G4double F3 = c0 + c1*x + c2*x2 + c3*x 150 const G4double F3 = c0 + c1*x + c2*x2 + c3*x3 + c4*x4 + c5*x5;
178 // compute the approximated cross section 151 // compute the approximated cross section
179 xSection = (Z + 1.)*(F1*Z + F2*Z*Z + F3); 152 xSection = (Z + 1.)*(F1*Z + F2*Z*Z + F3);
180 // check if we are below the limit of the ap 153 // check if we are below the limit of the approximation and apply correction
181 if (gammaEnergyOrg < gammaEnergyLimit) { 154 if (gammaEnergyOrg < gammaEnergyLimit) {
182 const G4double dum = (gammaEnergyOrg-2.*kM 155 const G4double dum = (gammaEnergyOrg-2.*kMC2)/(gammaEnergyLimit-2.*kMC2);
183 xSection *= dum*dum; 156 xSection *= dum*dum;
184 } 157 }
185 // make sure that the cross section is never 158 // make sure that the cross section is never negative
186 xSection = std::max(xSection, 0.); 159 xSection = std::max(xSection, 0.);
187 return xSection; 160 return xSection;
188 } 161 }
189 162
190 // The secondaries e+e- energies are sampled u 163 // The secondaries e+e- energies are sampled using the Bethe - Heitler
191 // cross sections with Coulomb correction. 164 // cross sections with Coulomb correction.
192 // A modified version of the random number tec 165 // A modified version of the random number techniques of Butcher & Messel
193 // is used (Nuc Phys 20(1960),15). 166 // is used (Nuc Phys 20(1960),15).
194 // 167 //
195 // GEANT4 internal units. 168 // GEANT4 internal units.
196 // 169 //
197 // Note 1 : Effects due to the breakdown of th 170 // Note 1 : Effects due to the breakdown of the Born approximation at
198 // low energy are ignored. 171 // low energy are ignored.
199 // Note 2 : The differential cross section imp 172 // Note 2 : The differential cross section implicitly takes account of
200 // pair creation in both nuclear and 173 // pair creation in both nuclear and atomic electron fields.
201 // However triplet prodution is not g 174 // However triplet prodution is not generated.
202 void G4BetheHeitlerModel::SampleSecondaries(st 175 void G4BetheHeitlerModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect,
203 co 176 const G4MaterialCutsCouple* couple,
204 co 177 const G4DynamicParticle* aDynamicGamma,
205 G4 178 G4double, G4double)
206 { 179 {
207 // set some constant values 180 // set some constant values
208 const G4double gammaEnergy = aDynamicGamm 181 const G4double gammaEnergy = aDynamicGamma->GetKineticEnergy();
209 const G4double eps0 = CLHEP::elect 182 const G4double eps0 = CLHEP::electron_mass_c2/gammaEnergy;
210 // 183 //
211 // check kinematical limit: gamma energy(Eg) 184 // check kinematical limit: gamma energy(Eg) must be at least 2 e- rest mass
212 if (eps0 > 0.5) { return; } 185 if (eps0 > 0.5) { return; }
213 // 186 //
214 // select target element of the material (pr 187 // select target element of the material (probs. are based on partial x-secs)
215 const G4Element* anElement = SelectTargetAto 188 const G4Element* anElement = SelectTargetAtom(couple, fTheGamma, gammaEnergy,
216 aDyn 189 aDynamicGamma->GetLogKineticEnergy());
217 190
218 // 191 //
219 // get the random engine 192 // get the random engine
220 CLHEP::HepRandomEngine* rndmEngine = G4Rando 193 CLHEP::HepRandomEngine* rndmEngine = G4Random::getTheEngine();
221 // 194 //
222 // 'eps' is the total energy transferred to 195 // 'eps' is the total energy transferred to one of the e-/e+ pair in initial
223 // gamma energy units Eg. Since the correspo 196 // gamma energy units Eg. Since the corresponding DCS is symmetric on eps=0.5,
224 // the kinematical limits for eps0=mc^2/Eg < 197 // the kinematical limits for eps0=mc^2/Eg <= eps <= 0.5
225 // 1. 'eps' is sampled uniformly on the [eps 198 // 1. 'eps' is sampled uniformly on the [eps0, 0.5] inteval if Eg<Egsmall
226 // 2. otherwise, on the [eps_min, 0.5] inter 199 // 2. otherwise, on the [eps_min, 0.5] interval according to the DCS (case 2.)
227 G4double eps; 200 G4double eps;
228 // case 1. 201 // case 1.
229 static const G4double Egsmall = 2.*CLHEP::Me 202 static const G4double Egsmall = 2.*CLHEP::MeV;
230 if (gammaEnergy < Egsmall) { 203 if (gammaEnergy < Egsmall) {
231 eps = eps0 + (0.5-eps0)*rndmEngine->flat() 204 eps = eps0 + (0.5-eps0)*rndmEngine->flat();
232 } else { 205 } else {
233 // case 2. 206 // case 2.
234 // get the Coulomb factor for the target e 207 // get the Coulomb factor for the target element (Z) and gamma energy (Eg)
235 // F(Z) = 8*ln(Z)/3 if Eg <= 50 208 // F(Z) = 8*ln(Z)/3 if Eg <= 50 [MeV] => no Coulomb correction
236 // F(Z) = 8*ln(Z)/3 + 8*fc(Z) if Eg > 50 209 // F(Z) = 8*ln(Z)/3 + 8*fc(Z) if Eg > 50 [MeV] => fc(Z) is the Coulomb cor.
237 // 210 //
238 // The screening variable 'delta(eps)' = 1 211 // The screening variable 'delta(eps)' = 136*Z^{-1/3}*eps0/[eps(1-eps)]
239 // Due to the Coulomb correction, the DCS 212 // Due to the Coulomb correction, the DCS can go below zero even at
240 // kinematicaly allowed eps > eps0 values. 213 // kinematicaly allowed eps > eps0 values. In order to exclude this eps
241 // range with negative DCS, the minimum ep 214 // range with negative DCS, the minimum eps value will be set to eps_min =
242 // max[eps0, epsp] with epsp is the soluti 215 // max[eps0, epsp] with epsp is the solution of SF(delta(epsp)) - F(Z)/2 = 0
243 // with SF being the screening function (S 216 // with SF being the screening function (SF1=SF2 at high value of delta).
244 // The solution is epsp = 0.5 - 0.5*sqrt[ 217 // The solution is epsp = 0.5 - 0.5*sqrt[ 1 - 4*136*Z^{-1/3}eps0/deltap]
245 // with deltap = Exp[(42.038-F(Z))/8.29]-0 218 // with deltap = Exp[(42.038-F(Z))/8.29]-0.958. So the limits are:
246 // - when eps=eps_max = 0.5 => 219 // - when eps=eps_max = 0.5 => delta_min = 136*Z^{-1/3}*eps0/4
247 // - epsp = 0.5 - 0.5*sqrt[ 1 - delta_min/ 220 // - epsp = 0.5 - 0.5*sqrt[ 1 - delta_min/deltap]
248 // - and eps_min = max[eps0, epsp] 221 // - and eps_min = max[eps0, epsp]
249 static const G4double midEnergy = 50.*CLHE 222 static const G4double midEnergy = 50.*CLHEP::MeV;
250 const G4int iZet = std::min(gMa 223 const G4int iZet = std::min(gMaxZet, anElement->GetZasInt());
251 const G4double deltaFactor = 136.*eps0/an 224 const G4double deltaFactor = 136.*eps0/anElement->GetIonisation()->GetZ3();
252 G4double deltaMax = gElementData 225 G4double deltaMax = gElementData[iZet]->fDeltaMaxLow;
253 G4double FZ = 8.*anElement 226 G4double FZ = 8.*anElement->GetIonisation()->GetlogZ3();
254 if (gammaEnergy > midEnergy) { 227 if (gammaEnergy > midEnergy) {
255 FZ += 8.*(anElement->GetfCoulomb()) 228 FZ += 8.*(anElement->GetfCoulomb());
256 deltaMax = gElementData[iZet]->fDeltaMax 229 deltaMax = gElementData[iZet]->fDeltaMaxHigh;
257 } 230 }
258 const G4double deltaMin = 4.*deltaFactor; 231 const G4double deltaMin = 4.*deltaFactor;
259 // 232 //
260 // compute the limits of eps 233 // compute the limits of eps
261 const G4double epsp = 0.5 - 0.5*std::s 234 const G4double epsp = 0.5 - 0.5*std::sqrt(1. - deltaMin/deltaMax) ;
262 const G4double epsMin = std::max(eps0,ep 235 const G4double epsMin = std::max(eps0,epsp);
263 const G4double epsRange = 0.5 - epsMin; 236 const G4double epsRange = 0.5 - epsMin;
264 // 237 //
265 // sample the energy rate (eps) of the cre 238 // sample the energy rate (eps) of the created electron (or positron)
266 G4double F10, F20; 239 G4double F10, F20;
267 ScreenFunction12(deltaMin, F10, F20); 240 ScreenFunction12(deltaMin, F10, F20);
268 F10 -= FZ; 241 F10 -= FZ;
269 F20 -= FZ; 242 F20 -= FZ;
270 const G4double NormF1 = std::max(F10 * e 243 const G4double NormF1 = std::max(F10 * epsRange * epsRange, 0.);
271 const G4double NormF2 = std::max(1.5 * F 244 const G4double NormF2 = std::max(1.5 * F20 , 0.);
272 const G4double NormCond = NormF1/(NormF1 + 245 const G4double NormCond = NormF1/(NormF1 + NormF2);
273 // we will need 3 uniform random number fo 246 // we will need 3 uniform random number for each trial of sampling
274 G4double rndmv[3]; 247 G4double rndmv[3];
275 G4double greject = 0.; 248 G4double greject = 0.;
276 do { 249 do {
277 rndmEngine->flatArray(3, rndmv); 250 rndmEngine->flatArray(3, rndmv);
278 if (NormCond > rndmv[0]) { 251 if (NormCond > rndmv[0]) {
279 eps = 0.5 - epsRange * fG4Calc->A13(rn 252 eps = 0.5 - epsRange * fG4Calc->A13(rndmv[1]);
280 const G4double delta = deltaFactor/(ep 253 const G4double delta = deltaFactor/(eps*(1.-eps));
281 greject = (ScreenFunction1(delta)-FZ)/ 254 greject = (ScreenFunction1(delta)-FZ)/F10;
282 } else { 255 } else {
283 eps = epsMin + epsRange*rndmv[1]; 256 eps = epsMin + epsRange*rndmv[1];
284 const G4double delta = deltaFactor/(ep 257 const G4double delta = deltaFactor/(eps*(1.-eps));
285 greject = (ScreenFunction2(delta)-FZ)/ 258 greject = (ScreenFunction2(delta)-FZ)/F20;
286 } 259 }
287 // Loop checking, 03-Aug-2015, Vladimir 260 // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
288 } while (greject < rndmv[2]); 261 } while (greject < rndmv[2]);
289 } // end of eps sampling 262 } // end of eps sampling
290 // 263 //
291 // select charges randomly 264 // select charges randomly
292 G4double eTotEnergy, pTotEnergy; 265 G4double eTotEnergy, pTotEnergy;
293 if (rndmEngine->flat() > 0.5) { 266 if (rndmEngine->flat() > 0.5) {
294 eTotEnergy = (1.-eps)*gammaEnergy; 267 eTotEnergy = (1.-eps)*gammaEnergy;
295 pTotEnergy = eps*gammaEnergy; 268 pTotEnergy = eps*gammaEnergy;
296 } else { 269 } else {
297 pTotEnergy = (1.-eps)*gammaEnergy; 270 pTotEnergy = (1.-eps)*gammaEnergy;
298 eTotEnergy = eps*gammaEnergy; 271 eTotEnergy = eps*gammaEnergy;
299 } 272 }
300 // 273 //
301 // sample pair kinematics 274 // sample pair kinematics
302 const G4double eKinEnergy = std::max(0.,eTot 275 const G4double eKinEnergy = std::max(0.,eTotEnergy - CLHEP::electron_mass_c2);
303 const G4double pKinEnergy = std::max(0.,pTot 276 const G4double pKinEnergy = std::max(0.,pTotEnergy - CLHEP::electron_mass_c2);
304 // 277 //
305 G4ThreeVector eDirection, pDirection; 278 G4ThreeVector eDirection, pDirection;
306 // 279 //
307 GetAngularDistribution()->SamplePairDirectio 280 GetAngularDistribution()->SamplePairDirections(aDynamicGamma,
308 281 eKinEnergy, pKinEnergy,
309 282 eDirection, pDirection);
310 // create G4DynamicParticle object for the p 283 // create G4DynamicParticle object for the particle1
311 auto aParticle1= new G4DynamicParticle(fTheE << 284 G4DynamicParticle* aParticle1= new G4DynamicParticle(
>> 285 fTheElectron,eDirection,eKinEnergy);
312 // create G4DynamicParticle object for the p 286 // create G4DynamicParticle object for the particle2
313 auto aParticle2= new G4DynamicParticle(fTheP << 287 G4DynamicParticle* aParticle2= new G4DynamicParticle(
>> 288 fThePositron,pDirection,pKinEnergy);
314 // Fill output vector 289 // Fill output vector
315 fvect->push_back(aParticle1); 290 fvect->push_back(aParticle1);
316 fvect->push_back(aParticle2); 291 fvect->push_back(aParticle2);
317 // kill incident photon 292 // kill incident photon
318 fParticleChange->SetProposedKineticEnergy(0. 293 fParticleChange->SetProposedKineticEnergy(0.);
319 fParticleChange->ProposeTrackStatus(fStopAnd 294 fParticleChange->ProposeTrackStatus(fStopAndKill);
320 } 295 }
321 296
322 // should be called only by the master and at 297 // should be called only by the master and at initialisation
323 void G4BetheHeitlerModel::InitialiseElementDat 298 void G4BetheHeitlerModel::InitialiseElementData()
324 { 299 {
>> 300 G4int size = gElementData.size();
>> 301 if (size < gMaxZet+1) {
>> 302 gElementData.resize(gMaxZet+1, nullptr);
>> 303 }
325 // create for all elements that are in the d 304 // create for all elements that are in the detector
326 auto elemTable = G4Element::GetElementTable( << 305 const G4ElementTable* elemTable = G4Element::GetElementTable();
327 for (auto const & elem : *elemTable) { << 306 size_t numElems = (*elemTable).size();
328 const G4int Z = elem->GetZasInt(); << 307 for (size_t ie = 0; ie < numElems; ++ie) {
329 const G4int iz = std::min(gMaxZet, Z); << 308 const G4Element* elem = (*elemTable)[ie];
330 if (nullptr == gElementData[iz]) { // crea << 309 const G4int iz = std::min(gMaxZet, elem->GetZasInt());
>> 310 if (!gElementData[iz]) { // create it if doesn't exist yet
331 G4double FZLow = 8.*elem->GetIonisat 311 G4double FZLow = 8.*elem->GetIonisation()->GetlogZ3();
332 G4double FZHigh = FZLow + 8.*elem->Ge 312 G4double FZHigh = FZLow + 8.*elem->GetfCoulomb();
333 auto elD = new ElementData(); << 313 ElementData* elD = new ElementData();
334 elD->fDeltaMaxLow = G4Exp((42.038 - FZL 314 elD->fDeltaMaxLow = G4Exp((42.038 - FZLow )/8.29) - 0.958;
335 elD->fDeltaMaxHigh = G4Exp((42.038 - FZH 315 elD->fDeltaMaxHigh = G4Exp((42.038 - FZHigh)/8.29) - 0.958;
336 gElementData[iz] = elD; 316 gElementData[iz] = elD;
337 } 317 }
338 if (useEPICS2017 && Z < 101) { <<
339 fXSection->Retrieve(Z); <<
340 } <<
341 } 318 }
342 <<
343 } 319 }
344 320
345 321