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25 // 25 //
>> 26 // $Id$
26 // 27 //
27 // ------------------------------------------- 28 // -------------------------------------------------------------------
28 // 29 //
29 // GEANT4 Class file 30 // GEANT4 Class file
30 // 31 //
31 // 32 //
32 // File name: G4MuPairProductionModel 33 // File name: G4MuPairProductionModel
33 // 34 //
34 // Author: Vladimir Ivanchenko on base 35 // Author: Vladimir Ivanchenko on base of Laszlo Urban code
35 // 36 //
36 // Creation date: 24.06.2002 37 // Creation date: 24.06.2002
37 // 38 //
38 // Modifications: 39 // Modifications:
39 // 40 //
40 // 04-12-02 Change G4DynamicParticle construct 41 // 04-12-02 Change G4DynamicParticle constructor in PostStep (V.Ivanchenko)
41 // 23-12-02 Change interface in order to move 42 // 23-12-02 Change interface in order to move to cut per region (V.Ivanchenko)
42 // 24-01-03 Fix for compounds (V.Ivanchenko) 43 // 24-01-03 Fix for compounds (V.Ivanchenko)
43 // 27-01-03 Make models region aware (V.Ivanch 44 // 27-01-03 Make models region aware (V.Ivanchenko)
44 // 13-02-03 Add model (V.Ivanchenko) 45 // 13-02-03 Add model (V.Ivanchenko)
45 // 06-06-03 Fix in cross section calculation f 46 // 06-06-03 Fix in cross section calculation for high energy (V.Ivanchenko)
46 // 20-10-03 2*xi in ComputeDDMicroscopicCrossS 47 // 20-10-03 2*xi in ComputeDDMicroscopicCrossSection (R.Kokoulin)
47 // 8 integration points in ComputeDMi 48 // 8 integration points in ComputeDMicroscopicCrossSection
48 // 12-01-04 Take min cut of e- and e+ not its 49 // 12-01-04 Take min cut of e- and e+ not its sum (V.Ivanchenko)
49 // 10-02-04 Update parameterisation using R.Ko 50 // 10-02-04 Update parameterisation using R.Kokoulin model (V.Ivanchenko)
50 // 28-04-04 For complex materials repeat calcu 51 // 28-04-04 For complex materials repeat calculation of max energy for each
51 // material (V.Ivanchenko) 52 // material (V.Ivanchenko)
52 // 01-11-04 Fix bug inside ComputeDMicroscopic 53 // 01-11-04 Fix bug inside ComputeDMicroscopicCrossSection (R.Kokoulin)
53 // 08-04-05 Major optimisation of internal int 54 // 08-04-05 Major optimisation of internal interfaces (V.Ivantchenko)
54 // 03-08-05 Add SetParticle method (V.Ivantche 55 // 03-08-05 Add SetParticle method (V.Ivantchenko)
55 // 23-10-05 Add protection in sampling of e+e- 56 // 23-10-05 Add protection in sampling of e+e- pair energy needed for
56 // low cuts (V.Ivantchenko) 57 // low cuts (V.Ivantchenko)
57 // 13-02-06 Add ComputeCrossSectionPerAtom (mm 58 // 13-02-06 Add ComputeCrossSectionPerAtom (mma)
58 // 24-04-07 Add protection in SelectRandomAtom 59 // 24-04-07 Add protection in SelectRandomAtom method (V.Ivantchenko)
59 // 12-05-06 Updated sampling (use cut) in Sele 60 // 12-05-06 Updated sampling (use cut) in SelectRandomAtom (A.Bogdanov)
60 // 11-10-07 Add ignoreCut flag (V.Ivanchenko) 61 // 11-10-07 Add ignoreCut flag (V.Ivanchenko)
61 62
62 // 63 //
63 // Class Description: 64 // Class Description:
64 // 65 //
65 // 66 //
66 // ------------------------------------------- 67 // -------------------------------------------------------------------
67 // 68 //
68 //....oooOO0OOooo........oooOO0OOooo........oo 69 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
69 //....oooOO0OOooo........oooOO0OOooo........oo 70 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
70 71
71 #include "G4MuPairProductionModel.hh" 72 #include "G4MuPairProductionModel.hh"
72 #include "G4PhysicalConstants.hh" 73 #include "G4PhysicalConstants.hh"
73 #include "G4SystemOfUnits.hh" 74 #include "G4SystemOfUnits.hh"
74 #include "G4EmParameters.hh" <<
75 #include "G4Electron.hh" 75 #include "G4Electron.hh"
76 #include "G4Positron.hh" 76 #include "G4Positron.hh"
77 #include "G4MuonMinus.hh" 77 #include "G4MuonMinus.hh"
78 #include "G4MuonPlus.hh" 78 #include "G4MuonPlus.hh"
79 #include "Randomize.hh" 79 #include "Randomize.hh"
80 #include "G4Material.hh" 80 #include "G4Material.hh"
81 #include "G4Element.hh" 81 #include "G4Element.hh"
82 #include "G4ElementVector.hh" 82 #include "G4ElementVector.hh"
83 #include "G4ElementDataRegistry.hh" <<
84 #include "G4ProductionCutsTable.hh" 83 #include "G4ProductionCutsTable.hh"
85 #include "G4ParticleChangeForLoss.hh" 84 #include "G4ParticleChangeForLoss.hh"
86 #include "G4ModifiedMephi.hh" << 85 #include "G4ParticleChangeForGamma.hh"
87 #include "G4Log.hh" <<
88 #include "G4Exp.hh" <<
89 #include "G4AutoLock.hh" <<
90 <<
91 #include <iostream> <<
92 #include <fstream> <<
93 86
94 //....oooOO0OOooo........oooOO0OOooo........oo 87 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
95 88
96 const G4int G4MuPairProductionModel::ZDATPAIR[ << 89 // static members
97 << 90 //
98 const G4double G4MuPairProductionModel::xgi[] << 91 G4double G4MuPairProductionModel::zdat[]={1., 4., 13., 29., 92.};
99 0.0198550717512320, 0.1016667612931865, 0. << 92 G4double G4MuPairProductionModel::adat[]={1.01, 9.01, 26.98, 63.55, 238.03};
100 0.5917173212478250, 0.7627662049581645, 0. << 93 G4double G4MuPairProductionModel::tdat[]={1.e3, 1.e4, 1.e5, 1.e6, 1.e7, 1.e8,
101 }; << 94 1.e9, 1.e10};
102 << 95 G4double G4MuPairProductionModel::xgi[]={ 0.0199, 0.1017, 0.2372, 0.4083,
103 const G4double G4MuPairProductionModel::wgi[] << 96 0.5917, 0.7628, 0.8983, 0.9801 };
104 0.0506142681451880, 0.1111905172266870, 0. << 97 G4double G4MuPairProductionModel::wgi[]={ 0.0506, 0.1112, 0.1569, 0.1813,
105 0.1813418916891810, 0.1568533229389435, 0. << 98 0.1813, 0.1569, 0.1112, 0.0506 };
106 }; <<
107 <<
108 namespace <<
109 { <<
110 G4Mutex theMuPairMutex = G4MUTEX_INITIALIZER <<
111 <<
112 const G4double ak1 = 6.9; <<
113 const G4double ak2 = 1.0; <<
114 } <<
115 99
116 //....oooOO0OOooo........oooOO0OOooo........oo 100 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
117 101
>> 102 using namespace std;
>> 103
118 G4MuPairProductionModel::G4MuPairProductionMod 104 G4MuPairProductionModel::G4MuPairProductionModel(const G4ParticleDefinition* p,
119 105 const G4String& nam)
120 : G4VEmModel(nam), 106 : G4VEmModel(nam),
121 factorForCross(CLHEP::fine_structure_const*C << 107 particle(0),
122 CLHEP::classic_electr_radius*CLHEP::class << 108 factorForCross(4.*fine_structure_const*fine_structure_const
123 4./(3.*CLHEP::pi)), << 109 *classic_electr_radius*classic_electr_radius/(3.*pi)),
124 sqrte(std::sqrt(G4Exp(1.))), << 110 sqrte(sqrt(exp(1.))),
125 minPairEnergy(4.*CLHEP::electron_mass_c2), << 111 currentZ(0),
126 lowestKinEnergy(0.85*CLHEP::GeV) << 112 fParticleChange(0),
>> 113 minPairEnergy(4.*electron_mass_c2),
>> 114 lowestKinEnergy(GeV),
>> 115 nzdat(5),
>> 116 ntdat(8),
>> 117 nbiny(1000),
>> 118 nmaxElements(0),
>> 119 ymin(-5.),
>> 120 ymax(0.),
>> 121 dy((ymax-ymin)/nbiny),
>> 122 samplingTablesAreFilled(false)
127 { 123 {
>> 124 SetLowEnergyLimit(minPairEnergy);
128 nist = G4NistManager::Instance(); 125 nist = G4NistManager::Instance();
129 126
130 theElectron = G4Electron::Electron(); 127 theElectron = G4Electron::Electron();
131 thePositron = G4Positron::Positron(); 128 thePositron = G4Positron::Positron();
132 129
133 if(nullptr != p) { << 130 particleMass = lnZ = z13 = z23 = 0;
134 SetParticle(p); <<
135 lowestKinEnergy = std::max(lowestKinEnergy <<
136 } <<
137 emin = lowestKinEnergy; <<
138 emax = emin*10000.; <<
139 SetAngularDistribution(new G4ModifiedMephi() <<
140 } <<
141 131
142 //....oooOO0OOooo........oooOO0OOooo........oo << 132 for(size_t i=0; i<1001; ++i) { ya[i] = 0.0; }
143 133
144 G4double G4MuPairProductionModel::MinPrimaryEn << 134 if(p) { SetParticle(p); }
145 <<
146 <<
147 { <<
148 return std::max(lowestKinEnergy, cut); <<
149 } 135 }
150 136
151 //....oooOO0OOooo........oooOO0OOooo........oo 137 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
152 138
153 void G4MuPairProductionModel::Initialise(const << 139 G4MuPairProductionModel::~G4MuPairProductionModel()
154 const << 140 {}
155 { <<
156 SetParticle(p); <<
157 141
158 if (nullptr == fParticleChange) { << 142 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
159 fParticleChange = GetParticleChangeForLoss <<
160 <<
161 // define scale of internal table for each <<
162 if (0 == nbine) { <<
163 emin = std::max(lowestKinEnergy, LowEner <<
164 emax = std::max(HighEnergyLimit(), emin* <<
165 nbine = std::size_t(nYBinPerDecade*std:: <<
166 if(nbine < 3) { nbine = 3; } <<
167 143
168 ymin = G4Log(minPairEnergy/emin); << 144 G4double G4MuPairProductionModel::MinEnergyCut(const G4ParticleDefinition*,
169 dy = -ymin/G4double(nbiny); << 145 const G4MaterialCutsCouple* )
170 } << 146 {
171 if (p == particle) { << 147 return minPairEnergy;
172 G4int pdg = std::abs(p->GetPDGEncoding() << 148 }
173 if (pdg == 2212) { <<
174 dataName = "pEEPairProd"; <<
175 } else if (pdg == 321) { <<
176 dataName = "kaonEEPairProd"; <<
177 } else if (pdg == 211) { <<
178 dataName = "pionEEPairProd"; <<
179 } else if (pdg == 11) { <<
180 dataName = "eEEPairProd"; <<
181 } else if (pdg == 13) { <<
182 if (GetName() == "muToMuonPairProd") { <<
183 dataName = "muMuMuPairProd"; <<
184 } else { <<
185 dataName = "muEEPairProd"; <<
186 } <<
187 } <<
188 } <<
189 } <<
190 149
191 // for low-energy application this process s << 150 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
192 if(lowestKinEnergy >= HighEnergyLimit()) { r <<
193 151
194 if (p == particle) { << 152 G4double G4MuPairProductionModel::MaxSecondaryEnergy(const G4ParticleDefinition*,
195 fElementData = << 153 G4double kineticEnergy)
196 G4ElementDataRegistry::Instance()->GetEl << 154 {
197 if (nullptr == fElementData) { << 155 G4double maxPairEnergy = kineticEnergy + particleMass*(1.0 - 0.75*sqrte*z13);
198 G4AutoLock l(&theMuPairMutex); << 156 return maxPairEnergy;
199 fElementData = <<
200 G4ElementDataRegistry::Instance()->GetElemen <<
201 if (nullptr == fElementData) { <<
202 fElementData = new G4ElementData(NZDATPAIR); <<
203 fElementData->SetName(dataName); <<
204 } <<
205 G4bool useDataFile = G4EmParameters::Ins <<
206 if (useDataFile) { useDataFile = Retrie <<
207 if (!useDataFile) { MakeSamplingTables() <<
208 if (fTableToFile) { StoreTables(); } <<
209 l.unlock(); <<
210 } <<
211 if (IsMaster()) { <<
212 InitialiseElementSelectors(p, cuts); <<
213 } <<
214 } <<
215 } 157 }
216 158
217 //....oooOO0OOooo........oooOO0OOooo........oo << 159 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
218 160
219 void G4MuPairProductionModel::InitialiseLocal( << 161 void G4MuPairProductionModel::Initialise(const G4ParticleDefinition* p,
220 << 162 const G4DataVector&)
221 { << 163 {
222 if(p == particle && lowestKinEnergy < HighEn << 164 if (!samplingTablesAreFilled) {
223 SetElementSelectors(masterModel->GetElemen << 165 if(p) { SetParticle(p); }
>> 166 MakeSamplingTables();
224 } 167 }
>> 168 if(!fParticleChange) { fParticleChange = GetParticleChangeForLoss(); }
225 } 169 }
226 170
227 //....oooOO0OOooo........oooOO0OOooo........oo 171 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
228 172
229 G4double G4MuPairProductionModel::ComputeDEDXP 173 G4double G4MuPairProductionModel::ComputeDEDXPerVolume(
230 << 174 const G4Material* material,
231 175 const G4ParticleDefinition*,
232 176 G4double kineticEnergy,
233 177 G4double cutEnergy)
234 { 178 {
235 G4double dedx = 0.0; 179 G4double dedx = 0.0;
236 if (cutEnergy <= minPairEnergy || kineticEne 180 if (cutEnergy <= minPairEnergy || kineticEnergy <= lowestKinEnergy)
237 { return dedx; } 181 { return dedx; }
238 182
239 const G4ElementVector* theElementVector = ma 183 const G4ElementVector* theElementVector = material->GetElementVector();
240 const G4double* theAtomicNumDensityVector = 184 const G4double* theAtomicNumDensityVector =
241 material->G 185 material->GetAtomicNumDensityVector();
242 186
243 // loop for elements in the material 187 // loop for elements in the material
244 for (std::size_t i=0; i<material->GetNumberO << 188 for (size_t i=0; i<material->GetNumberOfElements(); ++i) {
245 G4double Z = (*theElementVector)[i]->GetZ 189 G4double Z = (*theElementVector)[i]->GetZ();
246 G4double tmax = MaxSecondaryEnergyForElem << 190 SetCurrentElement(Z);
>> 191 G4double tmax = MaxSecondaryEnergy(particle, kineticEnergy);
247 G4double loss = ComputMuPairLoss(Z, kinet 192 G4double loss = ComputMuPairLoss(Z, kineticEnergy, cutEnergy, tmax);
248 dedx += loss*theAtomicNumDensityVector[i] 193 dedx += loss*theAtomicNumDensityVector[i];
249 } 194 }
250 dedx = std::max(dedx, 0.0); << 195 if (dedx < 0.) { dedx = 0.; }
251 return dedx; 196 return dedx;
252 } 197 }
253 198
254 //....oooOO0OOooo........oooOO0OOooo........oo 199 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
255 200
256 G4double G4MuPairProductionModel::ComputMuPair 201 G4double G4MuPairProductionModel::ComputMuPairLoss(G4double Z,
257 << 202 G4double tkin,
258 << 203 G4double cutEnergy,
259 << 204 G4double tmax)
260 { 205 {
>> 206 SetCurrentElement(Z);
261 G4double loss = 0.0; 207 G4double loss = 0.0;
262 208
263 G4double cut = std::min(cutEnergy, tmax); << 209 G4double cut = std::min(cutEnergy,tmax);
264 if(cut <= minPairEnergy) { return loss; } 210 if(cut <= minPairEnergy) { return loss; }
265 211
266 // calculate the rectricted loss 212 // calculate the rectricted loss
267 // numerical integration in log(PairEnergy) 213 // numerical integration in log(PairEnergy)
268 G4double aaa = G4Log(minPairEnergy); << 214 G4double ak1=6.9;
269 G4double bbb = G4Log(cut); << 215 G4double ak2=1.0;
270 << 216 G4double aaa = log(minPairEnergy);
271 G4int kkk = std::min(std::max(G4lrint((bbb-a << 217 G4double bbb = log(cut);
272 G4double hhh = (bbb-aaa)/kkk; << 218 G4int kkk = (G4int)((bbb-aaa)/ak1+ak2);
>> 219 if (kkk > 8) kkk = 8;
>> 220 else if (kkk < 1) { kkk = 1; }
>> 221 G4double hhh = (bbb-aaa)/(G4double)kkk;
273 G4double x = aaa; 222 G4double x = aaa;
274 223
275 for (G4int l=0 ; l<kkk; ++l) { << 224 for (G4int l=0 ; l<kkk; l++)
276 for (G4int ll=0; ll<NINTPAIR; ++ll) { << 225 {
277 G4double ep = G4Exp(x+xgi[ll]*hhh); << 226
>> 227 for (G4int ll=0; ll<8; ll++)
>> 228 {
>> 229 G4double ep = exp(x+xgi[ll]*hhh);
278 loss += wgi[ll]*ep*ep*ComputeDMicroscopi 230 loss += wgi[ll]*ep*ep*ComputeDMicroscopicCrossSection(tkin, Z, ep);
279 } 231 }
280 x += hhh; 232 x += hhh;
281 } 233 }
282 loss *= hhh; 234 loss *= hhh;
283 loss = std::max(loss, 0.0); << 235 if (loss < 0.) loss = 0.;
284 return loss; 236 return loss;
285 } 237 }
286 238
287 //....oooOO0OOooo........oooOO0OOooo........oo 239 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
288 240
289 G4double G4MuPairProductionModel::ComputeMicro 241 G4double G4MuPairProductionModel::ComputeMicroscopicCrossSection(
290 G4d 242 G4double tkin,
291 G4d 243 G4double Z,
292 G4d << 244 G4double cut)
293 { 245 {
294 G4double cross = 0.; 246 G4double cross = 0.;
295 G4double tmax = MaxSecondaryEnergyForElement << 247 SetCurrentElement(Z);
296 G4double cut = std::max(cutEnergy, minPairE << 248 G4double tmax = MaxSecondaryEnergy(particle, tkin);
297 if (tmax <= cut) { return cross; } 249 if (tmax <= cut) { return cross; }
298 250
299 G4double aaa = G4Log(cut); << 251 G4double ak1=6.9 ;
300 G4double bbb = G4Log(tmax); << 252 G4double ak2=1.0 ;
301 G4int kkk = std::min(std::max(G4lrint((bbb-a << 253 G4double aaa = log(cut);
302 << 254 G4double bbb = log(tmax);
303 G4double hhh = (bbb-aaa)/(kkk); << 255 G4int kkk = (G4int)((bbb-aaa)/ak1 + ak2);
>> 256 if(kkk > 8) { kkk = 8; }
>> 257 else if(kkk < 1) { kkk = 1; }
>> 258 G4double hhh = (bbb-aaa)/G4double(kkk);
304 G4double x = aaa; 259 G4double x = aaa;
305 260
306 for (G4int l=0; l<kkk; ++l) { << 261 for(G4int l=0; l<kkk; ++l)
307 for (G4int i=0; i<NINTPAIR; ++i) { << 262 {
308 G4double ep = G4Exp(x + xgi[i]*hhh); << 263 for(G4int i=0; i<8; ++i)
>> 264 {
>> 265 G4double ep = exp(x + xgi[i]*hhh);
309 cross += ep*wgi[i]*ComputeDMicroscopicCr 266 cross += ep*wgi[i]*ComputeDMicroscopicCrossSection(tkin, Z, ep);
310 } 267 }
311 x += hhh; 268 x += hhh;
312 } 269 }
313 270
314 cross *= hhh; 271 cross *= hhh;
315 cross = std::max(cross, 0.0); << 272 if(cross < 0.0) { cross = 0.0; }
316 return cross; 273 return cross;
317 } 274 }
318 275
319 //....oooOO0OOooo........oooOO0OOooo........oo <<
320 <<
321 G4double G4MuPairProductionModel::ComputeDMicr 276 G4double G4MuPairProductionModel::ComputeDMicroscopicCrossSection(
322 G4d 277 G4double tkin,
323 G4d 278 G4double Z,
324 G4d 279 G4double pairEnergy)
325 // Calculates the differential (D) microscopi << 280 // Calculates the differential (D) microscopic cross section
326 // using the cross section formula of R.P. Kok << 281 // using the cross section formula of R.P. Kokoulin (18/01/98)
327 // Code modified by R.P. Kokoulin, V.N. Ivanch << 282 // Code modified by R.P. Kokoulin, V.N. Ivanchenko (27/01/04)
328 { << 283 {
329 static const G4double bbbtf= 183. ; << 284 G4double bbbtf= 183. ;
330 static const G4double bbbh = 202.4 ; << 285 G4double bbbh = 202.4 ;
331 static const G4double g1tf = 1.95e-5 ; << 286 G4double g1tf = 1.95e-5 ;
332 static const G4double g2tf = 5.3e-5 ; << 287 G4double g2tf = 5.3e-5 ;
333 static const G4double g1h = 4.4e-5 ; << 288 G4double g1h = 4.4e-5 ;
334 static const G4double g2h = 4.8e-5 ; << 289 G4double g2h = 4.8e-5 ;
335 <<
336 if (pairEnergy <= minPairEnergy) <<
337 return 0.0; <<
338 290
339 G4double totalEnergy = tkin + particleMass; 291 G4double totalEnergy = tkin + particleMass;
340 G4double residEnergy = totalEnergy - pairEn 292 G4double residEnergy = totalEnergy - pairEnergy;
>> 293 G4double massratio = particleMass/electron_mass_c2 ;
>> 294 G4double massratio2 = massratio*massratio ;
>> 295 G4double cross = 0.;
341 296
342 if (residEnergy <= 0.75*sqrte*z13*particleMa << 297 SetCurrentElement(Z);
343 return 0.0; <<
344 298
345 G4double a0 = 1.0 / (totalEnergy * residEner << 299 G4double c3 = 0.75*sqrte*particleMass;
346 G4double alf = 4.0 * electron_mass_c2 / pair << 300 if (residEnergy <= c3*z13) { return cross; }
347 G4double rt = std::sqrt(1.0 - alf); << 301
348 G4double delta = 6.0 * particleMass * partic << 302 G4double c7 = 4.*electron_mass_c2;
349 G4double tmnexp = alf/(1.0 + rt) + delta*rt; << 303 G4double c8 = 6.*particleMass*particleMass;
350 << 304 G4double alf = c7/pairEnergy;
351 if(tmnexp >= 1.0) { return 0.0; } << 305 G4double a3 = 1. - alf;
352 << 306 if (a3 <= 0.) { return cross; }
353 G4double tmn = G4Log(tmnexp); <<
354 <<
355 G4double massratio = particleMass/CLHEP::ele <<
356 G4double massratio2 = massratio*massratio; <<
357 G4double inv_massratio2 = 1.0 / massratio2; <<
358 307
359 // zeta calculation 308 // zeta calculation
360 G4double bbb,g1,g2; 309 G4double bbb,g1,g2;
361 if( Z < 1.5 ) { bbb = bbbh ; g1 = g1h ; g2 = 310 if( Z < 1.5 ) { bbb = bbbh ; g1 = g1h ; g2 = g2h ; }
362 else { bbb = bbbtf; g1 = g1tf; g2 = 311 else { bbb = bbbtf; g1 = g1tf; g2 = g2tf; }
363 312
364 G4double zeta = 0.0; << 313 G4double zeta = 0;
365 G4double z1exp = totalEnergy / (particleMass << 314 G4double zeta1 = 0.073*log(totalEnergy/(particleMass+g1*z23*totalEnergy))-0.26;
366 << 315 if ( zeta1 > 0.)
367 // 35.221047195922 is the root of zeta1(x) = <<
368 // condition below is the same as zeta1 > 0. <<
369 if (z1exp > 35.221047195922) <<
370 { 316 {
371 G4double z2exp = totalEnergy / (particleMa << 317 G4double zeta2 = 0.058*log(totalEnergy/(particleMass+g2*z13*totalEnergy))-0.14;
372 zeta = (0.073 * G4Log(z1exp) - 0.26) / (0. << 318 zeta = zeta1/zeta2 ;
373 } 319 }
374 320
375 G4double z2 = Z*(Z+zeta); 321 G4double z2 = Z*(Z+zeta);
376 G4double screen0 = 2.*electron_mass_c2*sqrte 322 G4double screen0 = 2.*electron_mass_c2*sqrte*bbb/(z13*pairEnergy);
377 G4double beta = 0.5*pairEnergy*pairEnergy*a0 << 323 G4double a0 = totalEnergy*residEnergy;
378 G4double xi0 = 0.5*massratio2*beta; << 324 G4double a1 = pairEnergy*pairEnergy/a0;
379 << 325 G4double bet = 0.5*a1;
380 // Gaussian integration in ln(1-ro) ( with 8 << 326 G4double xi0 = 0.25*massratio2*a1;
381 G4double rho[NINTPAIR]; << 327 G4double del = c8/a0;
382 G4double rho2[NINTPAIR]; << 328
383 G4double xi[NINTPAIR]; << 329 G4double rta3 = sqrt(a3);
384 G4double xi1[NINTPAIR]; << 330 G4double tmnexp = alf/(1. + rta3) + del*rta3;
385 G4double xii[NINTPAIR]; << 331 if(tmnexp >= 1.0) return cross;
386 <<
387 for (G4int i = 0; i < NINTPAIR; ++i) <<
388 { <<
389 rho[i] = G4Exp(tmn*xgi[i]) - 1.0; // rho = <<
390 rho2[i] = rho[i] * rho[i]; <<
391 xi[i] = xi0*(1.0-rho2[i]); <<
392 xi1[i] = 1.0 + xi[i]; <<
393 xii[i] = 1.0 / xi[i]; <<
394 } <<
395 332
396 G4double ye1[NINTPAIR]; << 333 G4double tmn = log(tmnexp);
397 G4double ym1[NINTPAIR]; << 334 G4double sum = 0.;
398 335
399 G4double b40 = 4.0 * beta; << 336 // Gaussian integration in ln(1-ro) ( with 8 points)
400 G4double b62 = 6.0 * beta + 2.0; << 337 for (G4int i=0; i<8; ++i)
401 <<
402 for (G4int i = 0; i < NINTPAIR; ++i) <<
403 { 338 {
404 G4double yeu = (b40 + 5.0) + (b40 - 1.0) * << 339 G4double a4 = exp(tmn*xgi[i]); // a4 = (1.-asymmetry)
405 G4double yed = b62*G4Log(3.0 + xii[i]) + ( << 340 G4double a5 = a4*(2.-a4) ;
406 << 341 G4double a6 = 1.-a5 ;
407 G4double ymu = b62 * (1.0 + rho2[i]) + 6.0 << 342 G4double a7 = 1.+a6 ;
408 G4double ymd = (b40 + 3.0)*(1.0 + rho2[i]) << 343 G4double a9 = 3.+a6 ;
409 + 2.0 - 3.0 * rho2[i]; << 344 G4double xi = xi0*a5 ;
410 << 345 G4double xii = 1./xi ;
411 ye1[i] = 1.0 + yeu / yed; << 346 G4double xi1 = 1.+xi ;
412 ym1[i] = 1.0 + ymu / ymd; << 347 G4double screen = screen0*xi1/a5 ;
413 } << 348 G4double yeu = 5.-a6+4.*bet*a7 ;
414 << 349 G4double yed = 2.*(1.+3.*bet)*log(3.+xii)-a6-a1*(2.-a6) ;
415 G4double be[NINTPAIR]; << 350 G4double ye1 = 1.+yeu/yed ;
416 G4double bm[NINTPAIR]; << 351 G4double ale=log(bbb/z13*sqrt(xi1*ye1)/(1.+screen*ye1)) ;
417 << 352 G4double cre = 0.5*log(1.+2.25*z23*xi1*ye1/massratio2) ;
418 for(G4int i = 0; i < NINTPAIR; ++i) { << 353 G4double be;
419 if(xi[i] <= 1000.0) { << 354
420 be[i] = ((2.0 + rho2[i])*(1.0 + beta) + << 355 if (xi <= 1.e3) be = ((2.+a6)*(1.+bet)+xi*a9)*log(1.+xii)+(a5-bet)/xi1-a9;
421 xi[i]*(3.0 + rho2[i]))*G4Log(1.0 + xi << 356 else be = (3.-a6+a1*a7)/(2.*xi);
422 (1.0 - rho2[i] - beta)/xi1[i] - (3.0 + rho2[ << 357
>> 358 G4double fe = (ale-cre)*be;
>> 359 if ( fe < 0.) fe = 0. ;
>> 360
>> 361 G4double ymu = 4.+a6 +3.*bet*a7 ;
>> 362 G4double ymd = a7*(1.5+a1)*log(3.+xi)+1.-1.5*a6 ;
>> 363 G4double ym1 = 1.+ymu/ymd ;
>> 364 G4double alm_crm = log(bbb*massratio/(1.5*z23*(1.+screen*ym1)));
>> 365 G4double a10,bm;
>> 366 if ( xi >= 1.e-3)
>> 367 {
>> 368 a10 = (1.+a1)*a5 ;
>> 369 bm = (a7*(1.+1.5*bet)-a10*xii)*log(xi1)+xi*(a5-bet)/xi1+a10;
423 } else { 370 } else {
424 be[i] = 0.5*(3.0 - rho2[i] + 2.0*beta*(1 << 371 bm = (5.-a6+bet*a9)*(xi/2.);
425 } 372 }
426 373
427 if(xi[i] >= 0.001) { << 374 G4double fm = alm_crm*bm;
428 G4double a10 = (1.0 + 2.0 * beta) * (1.0 << 375 if ( fm < 0.) fm = 0. ;
429 bm[i] = ((1.0 + rho2[i])*(1.0 + 1.5 * be <<
430 xi[i] * (1.0 - rho2[i] - beta) <<
431 } else { <<
432 bm[i] = 0.5*(5.0 - rho2[i] + beta * (3.0 <<
433 } <<
434 } <<
435 <<
436 G4double sum = 0.0; <<
437 <<
438 for (G4int i = 0; i < NINTPAIR; ++i) { <<
439 G4double screen = screen0*xi1[i]/(1.0 - rh <<
440 G4double ale = G4Log(bbb/z13*std::sqrt(xi1 <<
441 G4double cre = 0.5*G4Log(1. + 2.25*z23*xi1 <<
442 <<
443 G4double fe = (ale-cre)*be[i]; <<
444 fe = std::max(fe, 0.0); <<
445 376
446 G4double alm_crm = G4Log(bbb*massratio/(1. << 377 sum += wgi[i]*a4*(fe+fm/massratio2);
447 G4double fm = std::max(alm_crm*bm[i], 0.0) <<
448 <<
449 sum += wgi[i]*(1.0 + rho[i])*(fe + fm); <<
450 } 378 }
451 379
452 return -tmn*sum*factorForCross*z2*residEnerg << 380 cross = -tmn*sum*factorForCross*z2*residEnergy/(totalEnergy*pairEnergy);
>> 381
>> 382 return cross;
453 } 383 }
454 384
455 //....oooOO0OOooo........oooOO0OOooo........oo 385 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
456 386
457 G4double G4MuPairProductionModel::ComputeCross 387 G4double G4MuPairProductionModel::ComputeCrossSectionPerAtom(
458 con 388 const G4ParticleDefinition*,
459 389 G4double kineticEnergy,
460 << 390 G4double Z, G4double,
461 391 G4double cutEnergy,
462 392 G4double maxEnergy)
463 { 393 {
464 G4double cross = 0.0; 394 G4double cross = 0.0;
465 if (kineticEnergy <= lowestKinEnergy) { retu 395 if (kineticEnergy <= lowestKinEnergy) { return cross; }
466 396
467 G4double maxPairEnergy = MaxSecondaryEnergyF << 397 SetCurrentElement(Z);
>> 398
>> 399 G4double maxPairEnergy = MaxSecondaryEnergy(particle,kineticEnergy);
468 G4double tmax = std::min(maxEnergy, maxPairE 400 G4double tmax = std::min(maxEnergy, maxPairEnergy);
469 G4double cut = std::max(cutEnergy, minPairE 401 G4double cut = std::max(cutEnergy, minPairEnergy);
470 if (cut >= tmax) { return cross; } << 402 if (cut >= tmax) return cross;
471 403
472 cross = ComputeMicroscopicCrossSection(kinet << 404 cross = ComputeMicroscopicCrossSection (kineticEnergy, Z, cut);
473 if(tmax < kineticEnergy) { 405 if(tmax < kineticEnergy) {
474 cross -= ComputeMicroscopicCrossSection(ki 406 cross -= ComputeMicroscopicCrossSection(kineticEnergy, Z, tmax);
475 } 407 }
476 return cross; 408 return cross;
477 } 409 }
478 410
479 //....oooOO0OOooo........oooOO0OOooo........oo 411 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
480 412
481 void G4MuPairProductionModel::MakeSamplingTabl 413 void G4MuPairProductionModel::MakeSamplingTables()
482 { 414 {
483 G4double factore = G4Exp(G4Log(emax/emin)/G4 << 415 for (G4int iz=0; iz<nzdat; ++iz)
>> 416 {
>> 417 G4double Z = zdat[iz];
>> 418 SetCurrentElement(Z);
>> 419
>> 420 for (G4int it=0; it<ntdat; ++it) {
484 421
485 for (G4int iz=0; iz<NZDATPAIR; ++iz) { << 422 G4double kineticEnergy = tdat[it];
>> 423 G4double maxPairEnergy = MaxSecondaryEnergy(particle,kineticEnergy);
>> 424 // G4cout << "Z= " << currentZ << " z13= " << z13
>> 425 //<< " mE= " << maxPairEnergy << G4endl;
>> 426 G4double xSec = 0.0 ;
>> 427
>> 428 if(maxPairEnergy > minPairEnergy) {
>> 429
>> 430 G4double y = ymin - 0.5*dy ;
>> 431 G4double yy = ymin - dy ;
>> 432 G4double x = exp(y);
>> 433 G4double fac = exp(dy);
>> 434 G4double dx = exp(yy)*(fac - 1.0);
>> 435
>> 436 G4double c = log(maxPairEnergy/minPairEnergy);
>> 437
>> 438 for (G4int i=0 ; i<nbiny; ++i) {
>> 439 y += dy ;
>> 440 if(c > 0.0) {
>> 441 x *= fac;
>> 442 dx*= fac;
>> 443 G4double ep = minPairEnergy*exp(c*x) ;
>> 444 xSec +=
>> 445 ep*dx*ComputeDMicroscopicCrossSection(kineticEnergy, Z, ep);
>> 446 }
>> 447 ya[i] = y;
>> 448 proba[iz][it][i] = xSec;
>> 449 }
>> 450
>> 451 } else {
>> 452 for (G4int i=0 ; i<nbiny; ++i) {
>> 453 proba[iz][it][i] = xSec;
>> 454 }
>> 455 }
486 456
487 G4double Z = ZDATPAIR[iz]; << 457 ya[nbiny]=ymax;
488 G4Physics2DVector* pv = new G4Physics2DVec << 458 proba[iz][it][nbiny] = xSec;
489 G4double kinEnergy = emin; <<
490 <<
491 for (std::size_t it=0; it<=nbine; ++it) { <<
492 <<
493 pv->PutY(it, G4Log(kinEnergy/CLHEP::MeV) <<
494 G4double maxPairEnergy = MaxSecondaryEne <<
495 /* <<
496 G4cout << "it= " << it << " E= " << kinE <<
497 << " " << particle->GetParticleN <<
498 << " maxE= " << maxPairEnergy << <<
499 << " ymin= " << ymin << G4endl; <<
500 */ <<
501 G4double coef = G4Log(minPairEnergy/kinE <<
502 G4double ymax = G4Log(maxPairEnergy/kinE <<
503 G4double fac = (ymax - ymin)/dy; <<
504 std::size_t imax = (std::size_t)fac; <<
505 fac -= (G4double)imax; <<
506 <<
507 G4double xSec = 0.0; <<
508 G4double x = ymin; <<
509 /* <<
510 G4cout << "Z= " << currentZ << " z13= " <<
511 << " mE= " << maxPairEnergy << " <<
512 << " dy= " << dy << " c= " << co <<
513 */ <<
514 // start from zero <<
515 pv->PutValue(0, it, 0.0); <<
516 if(0 == it) { pv->PutX(nbiny, 0.0); } <<
517 <<
518 for (std::size_t i=0; i<nbiny; ++i) { <<
519 <<
520 if(0 == it) { pv->PutX(i, x); } <<
521 <<
522 if(i < imax) { <<
523 G4double ep = kinEnergy*G4Exp(coef*( <<
524 <<
525 // not multiplied by interval, becau <<
526 // will be used only for sampling <<
527 //G4cout << "i= " << i << " x= " << <<
528 // << " Egamma= " << ep << G <<
529 xSec += ep*ComputeDMicroscopicCrossS <<
530 <<
531 // last bin before the kinematic lim <<
532 } else if(i == imax) { <<
533 G4double ep = kinEnergy*G4Exp(coef*( <<
534 xSec += ep*fac*ComputeDMicroscopicCr <<
535 } <<
536 pv->PutValue(i + 1, it, xSec); <<
537 x += dy; <<
538 } <<
539 kinEnergy *= factore; <<
540 459
541 // to avoid precision lost <<
542 if(it+1 == nbine) { kinEnergy = emax; } <<
543 } 460 }
544 fElementData->InitialiseForElement(iz, pv) <<
545 } 461 }
>> 462 samplingTablesAreFilled = true;
546 } 463 }
547 464
548 //....oooOO0OOooo........oooOO0OOooo........oo 465 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
549 466
550 void G4MuPairProductionModel::SampleSecondarie << 467 void
551 std::vector<G4Dy << 468 G4MuPairProductionModel::SampleSecondaries(std::vector<G4DynamicParticle*>* vdp,
552 const G4Material << 469 const G4MaterialCutsCouple* couple,
553 const G4DynamicP << 470 const G4DynamicParticle* aDynamicParticle,
554 G4double tmin, << 471 G4double tmin,
555 G4double tmax) << 472 G4double tmax)
556 { 473 {
557 G4double kinEnergy = aDynamicParticle->GetKi << 474 G4double kineticEnergy = aDynamicParticle->GetKineticEnergy();
558 //G4cout << "------- G4MuPairProductionModel << 475 G4double totalEnergy = kineticEnergy + particleMass;
559 // << kinEnergy << " " <<
560 // << aDynamicParticle->GetDefinitio <<
561 G4double totalEnergy = kinEnergy + particl <<
562 G4double totalMomentum = 476 G4double totalMomentum =
563 std::sqrt(kinEnergy*(kinEnergy + 2.0*parti << 477 sqrt(kineticEnergy*(kineticEnergy + 2.0*particleMass));
564 478
565 G4ThreeVector partDirection = aDynamicPartic 479 G4ThreeVector partDirection = aDynamicParticle->GetMomentumDirection();
566 480
567 // select randomly one element constituing t << 481 G4int it;
568 const G4Element* anElement = SelectRandomAto << 482 for(it=1; it<ntdat; ++it) { if(kineticEnergy <= tdat[it]) { break; } }
>> 483 if(it == ntdat) { --it; }
>> 484 G4double dt = log(kineticEnergy/tdat[it-1])/log(tdat[it]/tdat[it-1]);
569 485
570 // define interval of energy transfer << 486 // select randomly one element constituing the material
571 G4double maxPairEnergy = MaxSecondaryEnergyF << 487 const G4Element* anElement =
572 << 488 SelectRandomAtom(kineticEnergy, dt, it, couple, tmin);
573 G4double maxEnergy = std::min(tmax, maxPairE << 489 SetCurrentElement(anElement->GetZ());
574 G4double minEnergy = std::max(tmin, minPairE << 490
>> 491 // define interval of enegry transfer
>> 492 G4double maxPairEnergy = MaxSecondaryEnergy(particle,kineticEnergy);
>> 493 G4double maxEnergy = std::min(tmax, maxPairEnergy);
>> 494 G4double minEnergy = std::max(tmin, minPairEnergy);
575 495
576 if (minEnergy >= maxEnergy) { return; } << 496 if(minEnergy >= maxEnergy) { return; }
577 //G4cout << "emin= " << minEnergy << " emax= 497 //G4cout << "emin= " << minEnergy << " emax= " << maxEnergy
578 // << " minPair= " << minPairEnergy << " max << 498 // << " minPair= " << minPairEnergy << " maxpair= " << maxPairEnergy
579 // << " ymin= " << ymin << " dy= " << dy << 499 // << " ymin= " << ymin << " dy= " << dy << G4endl;
580 500
581 G4double coeff = G4Log(minPairEnergy/kinEner << 501 G4double logmaxmin = log(maxPairEnergy/minPairEnergy);
582 502
583 // compute limits << 503 // select bins
584 G4double yymin = G4Log(minEnergy/kinEnergy)/ << 504 G4int iymin = 0;
585 G4double yymax = G4Log(maxEnergy/kinEnergy)/ << 505 G4int iymax = nbiny-1;
586 << 506 if( minEnergy > minPairEnergy)
587 //G4cout << "yymin= " << yymin << " yymax= << 507 {
588 << 508 G4double xc = log(minEnergy/minPairEnergy)/logmaxmin;
589 // units should not be used, bacause table w << 509 iymin = (G4int)((log(xc) - ymin)/dy);
590 G4double logTkin = G4Log(kinEnergy/CLHEP::Me << 510 if(iymin >= nbiny) iymin = nbiny-1;
>> 511 else if(iymin < 0) iymin = 0;
>> 512 xc = log(maxEnergy/minPairEnergy)/logmaxmin;
>> 513 iymax = (G4int)((log(xc) - ymin)/dy) + 1;
>> 514 if(iymax >= nbiny) iymax = nbiny-1;
>> 515 else if(iymax < 0) iymax = 0;
>> 516 }
591 517
592 // sample e-e+ energy, pair energy first 518 // sample e-e+ energy, pair energy first
>> 519 G4int iz, iy;
593 520
594 // select sample table via Z << 521 for(iz=1; iz<nzdat; ++iz) { if(currentZ <= zdat[iz]) { break; } }
595 G4int iz1(0), iz2(0); << 522 if(iz == nzdat) { --iz; }
596 for (G4int iz=0; iz<NZDATPAIR; ++iz) { << 523
597 if(currentZ == ZDATPAIR[iz]) { << 524 G4double dz = log(currentZ/zdat[iz-1])/log(zdat[iz]/zdat[iz-1]);
598 iz1 = iz2 = iz; << 525
599 break; << 526 G4double pmin = InterpolatedIntegralCrossSection(dt,dz,iz,it,iymin,currentZ);
600 } else if(currentZ < ZDATPAIR[iz]) { << 527 G4double pmax = InterpolatedIntegralCrossSection(dt,dz,iz,it,iymax,currentZ);
601 iz2 = iz; << 528
602 if(iz > 0) { iz1 = iz-1; } << 529 G4double p = pmin+G4UniformRand()*(pmax - pmin);
603 else { iz1 = iz2; } << 530
604 break; << 531 // interpolate sampling vector;
605 } << 532 G4double p1 = pmin;
606 } << 533 G4double p2 = pmin;
607 if (0 == iz1) { iz1 = iz2 = NZDATPAIR-1; } << 534 for(iy=iymin+1; iy<=iymax; ++iy) {
608 << 535 p1 = p2;
609 G4double pairEnergy = 0.0; << 536 p2 = InterpolatedIntegralCrossSection(dt, dz, iz, it, iy, currentZ);
610 G4int count = 0; << 537 if(p <= p2) { break; }
611 //G4cout << "start loop Z1= " << iz1 << " Z2 << 538 }
612 do { << 539 // G4cout << "iy= " << iy << " iymin= " << iymin << " iymax= "
613 ++count; << 540 // << iymax << " Z= " << currentZ << G4endl;
614 // sampling using only one random number << 541 G4double y = ya[iy-1] + dy*(p - p1)/(p2 - p1);
615 G4double rand = G4UniformRand(); <<
616 <<
617 G4double x = FindScaledEnergy(iz1, rand, l <<
618 if(iz1 != iz2) { <<
619 G4double x2 = FindScaledEnergy(iz2, rand <<
620 G4double lz1= nist->GetLOGZ(ZDATPAIR[iz1 <<
621 G4double lz2= nist->GetLOGZ(ZDATPAIR[iz2 <<
622 //G4cout << count << ". x= " << x << " <<
623 // << " Z1= " << iz1 << " Z2 <<
624 x += (x2 - x)*(lnZ - lz1)/(lz2 - lz1); <<
625 } <<
626 //G4cout << "x= " << x << " coeff= " << c <<
627 pairEnergy = kinEnergy*G4Exp(x*coeff); <<
628 <<
629 // Loop checking, 03-Aug-2015, Vladimir Iv <<
630 } while((pairEnergy < minEnergy || pairEnerg <<
631 542
632 //G4cout << "## pairEnergy(GeV)= " << pairEn << 543 G4double PairEnergy = minPairEnergy*exp( exp(y)*logmaxmin );
633 // << " Etot(GeV)= " << totalEnergy/ << 544
>> 545 if(PairEnergy < minEnergy) { PairEnergy = minEnergy; }
>> 546 if(PairEnergy > maxEnergy) { PairEnergy = maxEnergy; }
634 547
635 // sample r=(E+-E-)/pairEnergy ( uniformly << 548 // sample r=(E+-E-)/PairEnergy ( uniformly .....)
636 G4double rmax = 549 G4double rmax =
637 (1.-6.*particleMass*particleMass/(totalEne << 550 (1.-6.*particleMass*particleMass/(totalEnergy*(totalEnergy-PairEnergy)))
638 *std::sqrt(1.-minPairEnergy/pairEnergy); << 551 *sqrt(1.-minPairEnergy/PairEnergy);
639 G4double r = rmax * (-1.+2.*G4UniformRand()) 552 G4double r = rmax * (-1.+2.*G4UniformRand()) ;
640 553
641 // compute energies from pairEnergy,r << 554 // compute energies from PairEnergy,r
642 G4double eEnergy = (1.-r)*pairEnergy*0.5; << 555 G4double ElectronEnergy = (1.-r)*PairEnergy*0.5;
643 G4double pEnergy = pairEnergy - eEnergy; << 556 G4double PositronEnergy = PairEnergy - ElectronEnergy;
644 << 557
645 // Sample angles << 558 // The angle of the emitted virtual photon is sampled
646 G4ThreeVector eDirection, pDirection; << 559 // according to the muon bremsstrahlung model
647 // << 560
648 GetAngularDistribution()->SamplePairDirectio << 561 G4double gam = totalEnergy/particleMass;
649 << 562 G4double gmax = gam*std::min(1.0, totalEnergy/PairEnergy - 1.0);
650 << 563 G4double gmax2= gmax*gmax;
651 // create G4DynamicParticle object for e+e- << 564 G4double x = G4UniformRand()*gmax2/(1.0 + gmax2);
652 eEnergy = std::max(eEnergy - CLHEP::electron << 565
653 pEnergy = std::max(pEnergy - CLHEP::electron << 566 G4double theta = sqrt(x/(1.0 - x))/gam;
654 auto aParticle1 = new G4DynamicParticle(theE << 567 G4double sint = sin(theta);
655 auto aParticle2 = new G4DynamicParticle(theP << 568 G4double phi = twopi * G4UniformRand() ;
656 // Fill output vector << 569 G4double dirx = sint*cos(phi), diry = sint*sin(phi), dirz = cos(theta) ;
657 vdp->push_back(aParticle1); << 570
658 vdp->push_back(aParticle2); << 571 G4ThreeVector gDirection(dirx, diry, dirz);
>> 572 gDirection.rotateUz(partDirection);
>> 573
>> 574 // the angles of e- and e+ assumed to be the same as virtual gamma
>> 575
>> 576 // create G4DynamicParticle object for the particle1
>> 577 G4DynamicParticle* aParticle1 =
>> 578 new G4DynamicParticle(theElectron, gDirection,
>> 579 ElectronEnergy - electron_mass_c2);
>> 580
>> 581 // create G4DynamicParticle object for the particle2
>> 582 G4DynamicParticle* aParticle2 =
>> 583 new G4DynamicParticle(thePositron, gDirection,
>> 584 PositronEnergy - electron_mass_c2);
659 585
660 // primary change 586 // primary change
661 kinEnergy -= pairEnergy; << 587 kineticEnergy -= (ElectronEnergy + PositronEnergy);
>> 588 fParticleChange->SetProposedKineticEnergy(kineticEnergy);
>> 589
662 partDirection *= totalMomentum; 590 partDirection *= totalMomentum;
663 partDirection -= (aParticle1->GetMomentum() 591 partDirection -= (aParticle1->GetMomentum() + aParticle2->GetMomentum());
664 partDirection = partDirection.unit(); 592 partDirection = partDirection.unit();
>> 593 fParticleChange->SetProposedMomentumDirection(partDirection);
665 594
666 // if energy transfer is higher than thresho << 595 // add secondary
667 // then stop tracking the primary particle a << 596 vdp->push_back(aParticle1);
668 if (pairEnergy > SecondaryThreshold()) { << 597 vdp->push_back(aParticle2);
669 fParticleChange->ProposeTrackStatus(fStopA <<
670 fParticleChange->SetProposedKineticEnergy( <<
671 auto newdp = new G4DynamicParticle(particl <<
672 vdp->push_back(newdp); <<
673 } else { // continue tracking the primary e- <<
674 fParticleChange->SetProposedMomentumDirect <<
675 fParticleChange->SetProposedKineticEnergy( <<
676 } <<
677 //G4cout << "-- G4MuPairProductionModel::Sam <<
678 } 598 }
679 599
680 //....oooOO0OOooo........oooOO0OOooo........oo 600 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
681 601
682 G4double << 602 const G4Element* G4MuPairProductionModel::SelectRandomAtom(
683 G4MuPairProductionModel::FindScaledEnergy(G4in << 603 G4double kinEnergy, G4double dt, G4int it,
684 G4double logTkin, << 604 const G4MaterialCutsCouple* couple, G4double tmin)
685 G4double yymin, G4double yymax) <<
686 { 605 {
687 G4double res = yymin; << 606 // select randomly 1 element within the material
688 G4Physics2DVector* pv = fElementData->GetEle << 607
689 if (nullptr != pv) { << 608 const G4Material* material = couple->GetMaterial();
690 G4double pmin = pv->Value(yymin, logTkin); << 609 size_t nElements = material->GetNumberOfElements();
691 G4double pmax = pv->Value(yymax, logTkin); << 610 const G4ElementVector* theElementVector = material->GetElementVector();
692 G4double p0 = pv->Value(0.0, logTkin); << 611 if (nElements == 1) { return (*theElementVector)[0]; }
693 if(p0 <= 0.0) { DataCorrupted(ZDATPAIR[iz] << 612
694 else { res = pv->FindLinearX((pmin + rand* << 613 if(nElements > nmaxElements) {
695 } else { << 614 nmaxElements = nElements;
696 DataCorrupted(ZDATPAIR[iz], logTkin); << 615 partialSum.resize(nmaxElements);
697 } 616 }
698 return res; <<
699 } <<
700 617
701 //....oooOO0OOooo........oooOO0OOooo........oo << 618 const G4double* theAtomNumDensityVector=material->GetAtomicNumDensityVector();
702 619
703 void G4MuPairProductionModel::DataCorrupted(G4 << 620 G4double sum = 0.0;
704 { << 621 G4double dl;
705 G4ExceptionDescription ed; <<
706 ed << "G4ElementData is not properly initial <<
707 << " Ekin(MeV)= " << G4Exp(logTkin) <<
708 << " IsMasterThread= " << IsMaster() <<
709 << " Model " << GetName(); <<
710 G4Exception("G4MuPairProductionModel::()", " <<
711 } <<
712 622
713 //....oooOO0OOooo........oooOO0OOooo........oo << 623 size_t i;
>> 624 for (i=0; i<nElements; ++i) {
>> 625 G4double Z = ((*theElementVector)[i])->GetZ();
>> 626 SetCurrentElement(Z);
>> 627 G4double maxPairEnergy = MaxSecondaryEnergy(particle,kinEnergy);
>> 628 G4double minEnergy = std::max(tmin, minPairEnergy);
>> 629 dl = 0.0;
>> 630 if(minEnergy < maxPairEnergy) {
>> 631
>> 632 G4int iz;
>> 633 for(iz=1; iz<nzdat; ++iz) {if(Z <= zdat[iz]) { break; } }
>> 634 if(iz == nzdat) { --iz; }
>> 635 G4double dz = log(Z/zdat[iz-1])/log(zdat[iz]/zdat[iz-1]);
>> 636
>> 637 G4double sigcut;
>> 638 if(minEnergy <= minPairEnergy)
>> 639 sigcut = 0.;
>> 640 else
>> 641 {
>> 642 G4double xc = log(minEnergy/minPairEnergy)/log(maxPairEnergy/minPairEnergy);
>> 643 G4int iy = (G4int)((log(xc) - ymin)/dy);
>> 644 if(iy < 0) { iy = 0; }
>> 645 if(iy >= nbiny) { iy = nbiny-1; }
>> 646 sigcut = InterpolatedIntegralCrossSection(dt,dz,iz,it,iy, Z);
>> 647 }
714 648
715 void G4MuPairProductionModel::StoreTables() co << 649 G4double sigtot = InterpolatedIntegralCrossSection(dt,dz,iz,it,nbiny,Z);
716 { << 650 dl = (sigtot - sigcut)*theAtomNumDensityVector[i];
717 for (G4int iz=0; iz<NZDATPAIR; ++iz) { <<
718 G4int Z = ZDATPAIR[iz]; <<
719 G4Physics2DVector* pv = fElementData->GetE <<
720 if(nullptr == pv) { <<
721 DataCorrupted(Z, 1.0); <<
722 return; <<
723 } 651 }
724 std::ostringstream ss; << 652 // protection
725 ss << "mupair/" << particle->GetParticleNa << 653 if(dl < 0.0) { dl = 0.0; }
726 std::ofstream outfile(ss.str()); << 654 sum += dl;
727 pv->Store(outfile); << 655 partialSum[i] = sum;
728 } 656 }
729 } <<
730 <<
731 //....oooOO0OOooo........oooOO0OOooo........oo <<
732 657
733 G4bool G4MuPairProductionModel::RetrieveTables << 658 G4double rval = G4UniformRand()*sum;
734 { << 659 for (i=0; i<nElements; ++i) {
735 for (G4int iz=0; iz<NZDATPAIR; ++iz) { << 660 if(rval<=partialSum[i]) { return (*theElementVector)[i]; }
736 G4double Z = ZDATPAIR[iz]; <<
737 G4Physics2DVector* pv = new G4Physics2DVec <<
738 std::ostringstream ss; <<
739 ss << G4EmParameters::Instance()->GetDirLE <<
740 << particle->GetParticleName() << Z << <<
741 std::ifstream infile(ss.str(), std::ios::i <<
742 if(!pv->Retrieve(infile)) { <<
743 delete pv; <<
744 return false; <<
745 } <<
746 fElementData->InitialiseForElement(iz, pv) <<
747 } 661 }
748 return true; << 662
>> 663 return (*theElementVector)[nElements - 1];
>> 664
749 } 665 }
750 666
751 //....oooOO0OOooo........oooOO0OOooo........oo 667 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 668
>> 669
752 670