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25 // 22 //
>> 23 // $Id: G4MuPairProductionModel.cc,v 1.13 2003/10/21 13:30:05 maire Exp $
>> 24 // GEANT4 tag $Name: geant4-06-00-patch-01 $
26 // 25 //
27 // ------------------------------------------- 26 // -------------------------------------------------------------------
28 // 27 //
29 // GEANT4 Class file 28 // GEANT4 Class file
30 // 29 //
31 // 30 //
32 // File name: G4MuPairProductionModel 31 // File name: G4MuPairProductionModel
33 // 32 //
34 // Author: Vladimir Ivanchenko on base 33 // Author: Vladimir Ivanchenko on base of Laszlo Urban code
35 // 34 //
36 // Creation date: 24.06.2002 35 // Creation date: 24.06.2002
37 // 36 //
38 // Modifications: 37 // Modifications:
39 // 38 //
40 // 04-12-02 Change G4DynamicParticle construct 39 // 04-12-02 Change G4DynamicParticle constructor in PostStep (V.Ivanchenko)
41 // 23-12-02 Change interface in order to move 40 // 23-12-02 Change interface in order to move to cut per region (V.Ivanchenko)
42 // 24-01-03 Fix for compounds (V.Ivanchenko) 41 // 24-01-03 Fix for compounds (V.Ivanchenko)
43 // 27-01-03 Make models region aware (V.Ivanch 42 // 27-01-03 Make models region aware (V.Ivanchenko)
44 // 13-02-03 Add model (V.Ivanchenko) 43 // 13-02-03 Add model (V.Ivanchenko)
45 // 06-06-03 Fix in cross section calculation f 44 // 06-06-03 Fix in cross section calculation for high energy (V.Ivanchenko)
46 // 20-10-03 2*xi in ComputeDDMicroscopicCrossS 45 // 20-10-03 2*xi in ComputeDDMicroscopicCrossSection (R.Kokoulin)
47 // 8 integration points in ComputeDMi << 46 // 8 integration points in ComputeDMicroscopicCrossSection
48 // 12-01-04 Take min cut of e- and e+ not its <<
49 // 10-02-04 Update parameterisation using R.Ko <<
50 // 28-04-04 For complex materials repeat calcu <<
51 // material (V.Ivanchenko) <<
52 // 01-11-04 Fix bug inside ComputeDMicroscopic <<
53 // 08-04-05 Major optimisation of internal int <<
54 // 03-08-05 Add SetParticle method (V.Ivantche <<
55 // 23-10-05 Add protection in sampling of e+e- <<
56 // low cuts (V.Ivantchenko) <<
57 // 13-02-06 Add ComputeCrossSectionPerAtom (mm <<
58 // 24-04-07 Add protection in SelectRandomAtom <<
59 // 12-05-06 Updated sampling (use cut) in Sele <<
60 // 11-10-07 Add ignoreCut flag (V.Ivanchenko) <<
61 47
62 // 48 //
63 // Class Description: 49 // Class Description:
64 // 50 //
65 // 51 //
66 // ------------------------------------------- 52 // -------------------------------------------------------------------
67 // 53 //
68 //....oooOO0OOooo........oooOO0OOooo........oo 54 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
69 //....oooOO0OOooo........oooOO0OOooo........oo 55 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
70 56
71 #include "G4MuPairProductionModel.hh" 57 #include "G4MuPairProductionModel.hh"
72 #include "G4PhysicalConstants.hh" <<
73 #include "G4SystemOfUnits.hh" <<
74 #include "G4EmParameters.hh" <<
75 #include "G4Electron.hh" 58 #include "G4Electron.hh"
76 #include "G4Positron.hh" 59 #include "G4Positron.hh"
77 #include "G4MuonMinus.hh" 60 #include "G4MuonMinus.hh"
78 #include "G4MuonPlus.hh" 61 #include "G4MuonPlus.hh"
79 #include "Randomize.hh" 62 #include "Randomize.hh"
80 #include "G4Material.hh" 63 #include "G4Material.hh"
81 #include "G4Element.hh" 64 #include "G4Element.hh"
82 #include "G4ElementVector.hh" 65 #include "G4ElementVector.hh"
83 #include "G4ElementDataRegistry.hh" <<
84 #include "G4ProductionCutsTable.hh" 66 #include "G4ProductionCutsTable.hh"
85 #include "G4ParticleChangeForLoss.hh" <<
86 #include "G4ModifiedMephi.hh" <<
87 #include "G4Log.hh" <<
88 #include "G4Exp.hh" <<
89 #include "G4AutoLock.hh" <<
90 <<
91 #include <iostream> <<
92 #include <fstream> <<
93 67
94 //....oooOO0OOooo........oooOO0OOooo........oo 68 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
95 69
96 const G4int G4MuPairProductionModel::ZDATPAIR[ << 70 // static members
>> 71 //
>> 72 G4double G4MuPairProductionModel::zdat[]={1.,4.,13.,29.,92.};
>> 73 G4double G4MuPairProductionModel::adat[]={1.01,9.01,26.98,63.55,238.03};
>> 74 G4double G4MuPairProductionModel::tdat[]={1.e3,1.e4,1.e5,1.e6,1.e7,1.e8,
>> 75 1.e9,1.e10};
97 76
98 const G4double G4MuPairProductionModel::xgi[] << 77 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
99 0.0198550717512320, 0.1016667612931865, 0. <<
100 0.5917173212478250, 0.7627662049581645, 0. <<
101 }; <<
102 78
103 const G4double G4MuPairProductionModel::wgi[] << 79 G4MuPairProductionModel::G4MuPairProductionModel(const G4ParticleDefinition*,
104 0.0506142681451880, 0.1111905172266870, 0. << 80 const G4String& nam)
105 0.1813418916891810, 0.1568533229389435, 0. << 81 : G4VEmModel(nam),
106 }; << 82 minPairEnergy(4.*electron_mass_c2),
>> 83 highKinEnergy(1000000.*TeV),
>> 84 lowKinEnergy(minPairEnergy),
>> 85 nzdat(5),
>> 86 ntdat(8),
>> 87 NBIN(1000),
>> 88 samplingTablesAreFilled(false)
>> 89 { }
107 90
108 namespace << 91 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
109 { <<
110 G4Mutex theMuPairMutex = G4MUTEX_INITIALIZER <<
111 92
112 const G4double ak1 = 6.9; << 93 G4MuPairProductionModel::~G4MuPairProductionModel()
113 const G4double ak2 = 1.0; << 94 {
>> 95 size_t n = partialSumSigma.size();
>> 96 if(n > 0) {
>> 97 for(size_t i=0; i<n; i++) {
>> 98 delete partialSumSigma[i];
>> 99 }
>> 100 }
114 } 101 }
115 102
116 //....oooOO0OOooo........oooOO0OOooo........oo 103 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
117 104
118 G4MuPairProductionModel::G4MuPairProductionMod << 105 G4double G4MuPairProductionModel::HighEnergyLimit(const G4ParticleDefinition*)
119 <<
120 : G4VEmModel(nam), <<
121 factorForCross(CLHEP::fine_structure_const*C <<
122 CLHEP::classic_electr_radius*CLHEP::class <<
123 4./(3.*CLHEP::pi)), <<
124 sqrte(std::sqrt(G4Exp(1.))), <<
125 minPairEnergy(4.*CLHEP::electron_mass_c2), <<
126 lowestKinEnergy(0.85*CLHEP::GeV) <<
127 { 106 {
128 nist = G4NistManager::Instance(); << 107 return highKinEnergy;
129 <<
130 theElectron = G4Electron::Electron(); <<
131 thePositron = G4Positron::Positron(); <<
132 <<
133 if(nullptr != p) { <<
134 SetParticle(p); <<
135 lowestKinEnergy = std::max(lowestKinEnergy <<
136 } <<
137 emin = lowestKinEnergy; <<
138 emax = emin*10000.; <<
139 SetAngularDistribution(new G4ModifiedMephi() <<
140 } 108 }
141 109
142 //....oooOO0OOooo........oooOO0OOooo........oo 110 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
143 111
144 G4double G4MuPairProductionModel::MinPrimaryEn << 112 G4double G4MuPairProductionModel::LowEnergyLimit(const G4ParticleDefinition*)
145 <<
146 <<
147 { 113 {
148 return std::max(lowestKinEnergy, cut); << 114 return lowKinEnergy;
149 } 115 }
150 116
151 //....oooOO0OOooo........oooOO0OOooo........oo 117 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
152 118
153 void G4MuPairProductionModel::Initialise(const << 119 G4double G4MuPairProductionModel::MinEnergyCut(const G4ParticleDefinition*,
154 const << 120 const G4MaterialCutsCouple* couple)
155 { << 121 {
156 SetParticle(p); <<
157 122
158 if (nullptr == fParticleChange) { << 123 size_t index = couple->GetIndex();
159 fParticleChange = GetParticleChangeForLoss << 124 const G4ProductionCutsTable* theCoupleTable =
>> 125 G4ProductionCutsTable::GetProductionCutsTable();
160 126
161 // define scale of internal table for each << 127 G4double eCut = (*(theCoupleTable->GetEnergyCutsVector(1)))[index];
162 if (0 == nbine) { << 128 G4double pCut = (*(theCoupleTable->GetEnergyCutsVector(2)))[index];
163 emin = std::max(lowestKinEnergy, LowEner << 129 G4double x = 2*electron_mass_c2 + eCut + pCut;
164 emax = std::max(HighEnergyLimit(), emin* << 130 if(x < minPairEnergy) x = minPairEnergy;
165 nbine = std::size_t(nYBinPerDecade*std:: <<
166 if(nbine < 3) { nbine = 3; } <<
167 131
168 ymin = G4Log(minPairEnergy/emin); << 132 //// if (eCut < highKinEnergy && pCut < highKinEnergy) {
169 dy = -ymin/G4double(nbiny); << 133 //// x += eCut + pCut;
170 } << 134 //// } else {
171 if (p == particle) { << 135 //// x = 0.5*highKinEnergy;
172 G4int pdg = std::abs(p->GetPDGEncoding() << 136 //// }
173 if (pdg == 2212) { << 137
174 dataName = "pEEPairProd"; << 138 return x;
175 } else if (pdg == 321) { << 139 }
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 } <<
190 140
191 // for low-energy application this process s << 141 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
192 if(lowestKinEnergy >= HighEnergyLimit()) { r <<
193 142
194 if (p == particle) { << 143 G4bool G4MuPairProductionModel::IsInCharge(const G4ParticleDefinition* p)
195 fElementData = << 144 {
196 G4ElementDataRegistry::Instance()->GetEl << 145 return (p == G4MuonMinus::MuonMinus() || p == G4MuonPlus::MuonPlus());
197 if (nullptr == fElementData) { <<
198 G4AutoLock l(&theMuPairMutex); <<
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 } 146 }
216 147
217 //....oooOO0OOooo........oooOO0OOooo........oo << 148 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
218 149
219 void G4MuPairProductionModel::InitialiseLocal( << 150 void G4MuPairProductionModel::Initialise(const G4ParticleDefinition*,
220 << 151 const G4DataVector& cuts)
221 { 152 {
222 if(p == particle && lowestKinEnergy < HighEn << 153 const G4ProductionCutsTable* theCoupleTable =
223 SetElementSelectors(masterModel->GetElemen << 154 G4ProductionCutsTable::GetProductionCutsTable();
>> 155 size_t numOfCouples = theCoupleTable->GetTableSize();
>> 156 G4double fixedEnergy = sqrt(lowKinEnergy*highKinEnergy);
>> 157
>> 158 for (size_t ii=0; ii<partialSumSigma.size(); ii++) {
>> 159 G4DataVector* a=partialSumSigma[ii];
>> 160 if ( a ) delete a;
>> 161 }
>> 162 partialSumSigma.clear();
>> 163 for (size_t i=0; i<numOfCouples; i++) {
>> 164 const G4MaterialCutsCouple* couple=theCoupleTable->GetMaterialCutsCouple(i);
>> 165 const G4Material* material = couple->GetMaterial();
>> 166 G4DataVector* dv = ComputePartialSumSigma(material, fixedEnergy,
>> 167 std::min(cuts[i], 0.25*highKinEnergy));
>> 168 partialSumSigma.push_back(dv);
224 } 169 }
>> 170 if (!samplingTablesAreFilled) MakeSamplingTables();
225 } 171 }
226 172
227 //....oooOO0OOooo........oooOO0OOooo........oo 173 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
228 174
229 G4double G4MuPairProductionModel::ComputeDEDXP << 175 G4double
230 << 176 G4MuPairProductionModel::ComputeDEDX(const G4MaterialCutsCouple* couple,
231 << 177 const G4ParticleDefinition*,
232 << 178 G4double kineticEnergy, G4double cutEnergy)
233 <<
234 { 179 {
235 G4double dedx = 0.0; 180 G4double dedx = 0.0;
236 if (cutEnergy <= minPairEnergy || kineticEne << 181 if (minPairEnergy >= cutEnergy) return dedx;
237 { return dedx; } << 182 G4double cut = cutEnergy;
>> 183 if (kineticEnergy <= cutEnergy) cut = kineticEnergy;
238 184
>> 185 const G4Material* material = couple->GetMaterial();
239 const G4ElementVector* theElementVector = ma 186 const G4ElementVector* theElementVector = material->GetElementVector();
240 const G4double* theAtomicNumDensityVector = << 187 const G4double* theAtomicNumDensityVector =
241 material->G 188 material->GetAtomicNumDensityVector();
242 189
243 // loop for elements in the material 190 // loop for elements in the material
244 for (std::size_t i=0; i<material->GetNumberO << 191 for (size_t i=0; i<material->GetNumberOfElements(); i++) {
245 G4double Z = (*theElementVector)[i]->GetZ 192 G4double Z = (*theElementVector)[i]->GetZ();
246 G4double tmax = MaxSecondaryEnergyForElem << 193 G4double loss = ComputMuPairLoss(Z, kineticEnergy, cut);
247 G4double loss = ComputMuPairLoss(Z, kinet <<
248 dedx += loss*theAtomicNumDensityVector[i] 194 dedx += loss*theAtomicNumDensityVector[i];
249 } 195 }
250 dedx = std::max(dedx, 0.0); << 196 if (dedx < 0.) dedx = 0.;
251 return dedx; 197 return dedx;
252 } 198 }
253 199
254 //....oooOO0OOooo........oooOO0OOooo........oo 200 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
255 201
256 G4double G4MuPairProductionModel::ComputMuPair << 202 G4double
257 << 203 G4MuPairProductionModel::ComputMuPairLoss(G4double Z,
258 << 204 G4double tkin, G4double cutEnergy)
259 <<
260 { 205 {
>> 206 static const
>> 207 G4double xgi[] ={ 0.0199,0.1017,0.2372,0.4083,0.5917,0.7628,0.8983,0.9801};
>> 208 static const
>> 209 G4double wgi[] ={ 0.0506,0.1112,0.1569,0.1813,0.1813,0.1569,0.1112,0.0506};
>> 210 static const G4double ak1=6.9;
>> 211 static const G4double ak2=1.0;
>> 212 static const G4double sqrte = sqrt(exp(1.));
>> 213 static const G4double aaa = log(minPairEnergy);
>> 214 G4double z13 = pow(Z,0.333333333);
>> 215
261 G4double loss = 0.0; 216 G4double loss = 0.0;
262 217
263 G4double cut = std::min(cutEnergy, tmax); << 218 G4double particleMass = (G4MuonPlus::MuonPlus())->GetPDGMass();
264 if(cut <= minPairEnergy) { return loss; } << 219 G4double tmax = tkin + particleMass*(1.-0.75*sqrte*z13);
>> 220
>> 221 G4double cut = cutEnergy;
>> 222 if(tmax <= cutEnergy) cut = tmax;
>> 223 if(cut <= minPairEnergy) return loss;
265 224
266 // calculate the rectricted loss 225 // calculate the rectricted loss
267 // numerical integration in log(PairEnergy) 226 // numerical integration in log(PairEnergy)
268 G4double aaa = G4Log(minPairEnergy); << 227 G4double bbb = log(cut);
269 G4double bbb = G4Log(cut); << 228 G4int kkk = (G4int)((bbb-aaa)/ak1+ak2);
270 << 229 if (kkk > 8) kkk = 8;
271 G4int kkk = std::min(std::max(G4lrint((bbb-a << 230 G4double hhh = (bbb-aaa)/(G4double)kkk;
272 G4double hhh = (bbb-aaa)/kkk; <<
273 G4double x = aaa; 231 G4double x = aaa;
274 232
275 for (G4int l=0 ; l<kkk; ++l) { << 233 for (G4int l=0 ; l<kkk; l++)
276 for (G4int ll=0; ll<NINTPAIR; ++ll) { << 234 {
277 G4double ep = G4Exp(x+xgi[ll]*hhh); << 235
>> 236 for (G4int ll=0; ll<8; ll++)
>> 237 {
>> 238 G4double ep = exp(x+xgi[ll]*hhh);
278 loss += wgi[ll]*ep*ep*ComputeDMicroscopi 239 loss += wgi[ll]*ep*ep*ComputeDMicroscopicCrossSection(tkin, Z, ep);
279 } 240 }
280 x += hhh; 241 x += hhh;
281 } 242 }
282 loss *= hhh; 243 loss *= hhh;
283 loss = std::max(loss, 0.0); << 244 if (loss < 0.) loss = 0.;
284 return loss; 245 return loss;
285 } 246 }
286 247
287 //....oooOO0OOooo........oooOO0OOooo........oo 248 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
288 249
289 G4double G4MuPairProductionModel::ComputeMicro 250 G4double G4MuPairProductionModel::ComputeMicroscopicCrossSection(
290 G4d 251 G4double tkin,
291 G4d 252 G4double Z,
292 G4d << 253 G4double cut)
293 { <<
294 G4double cross = 0.; <<
295 G4double tmax = MaxSecondaryEnergyForElement <<
296 G4double cut = std::max(cutEnergy, minPairE <<
297 if (tmax <= cut) { return cross; } <<
298 <<
299 G4double aaa = G4Log(cut); <<
300 G4double bbb = G4Log(tmax); <<
301 G4int kkk = std::min(std::max(G4lrint((bbb-a <<
302 254
303 G4double hhh = (bbb-aaa)/(kkk); << 255 {
>> 256 static const G4double ak1=6.9 ;
>> 257 static const G4double ak2=1.0 ;
>> 258 static const G4double sqrte = sqrt(exp(1.));
>> 259 static const G4double
>> 260 xgi[]={ 0.0199,0.1017,0.2372,0.4083,0.5917,0.7628,0.8983,0.9801 };
>> 261 static const G4double
>> 262 wgi[]={ 0.0506,0.1112,0.1569,0.1813,0.1813,0.1569,0.1112,0.0506 };
>> 263 G4double z13 = pow(Z,0.333333333);
>> 264
>> 265 G4double cross = 0. ;
>> 266
>> 267 G4double particleMass = (G4MuonPlus::MuonPlus())->GetPDGMass();
>> 268 G4double tmax = tkin + particleMass*(1.-0.75*sqrte*z13);
>> 269
>> 270 if (tmax <= cut) return cross;
>> 271
>> 272 G4double aaa = log(cut);
>> 273 G4double bbb = log(tmax);
>> 274 G4int kkk = (G4int)((bbb-aaa)/ak1 + ak2);
>> 275 if(kkk > 8) kkk = 8;
>> 276 G4double hhh = (bbb-aaa)/float(kkk);
304 G4double x = aaa; 277 G4double x = aaa;
305 278
306 for (G4int l=0; l<kkk; ++l) { << 279 for(G4int l=0; l<kkk; l++)
307 for (G4int i=0; i<NINTPAIR; ++i) { << 280 {
308 G4double ep = G4Exp(x + xgi[i]*hhh); << 281 for(G4int i=0; i<8; i++)
>> 282 {
>> 283 G4double ep = exp(x + xgi[i]*hhh);
309 cross += ep*wgi[i]*ComputeDMicroscopicCr 284 cross += ep*wgi[i]*ComputeDMicroscopicCrossSection(tkin, Z, ep);
310 } 285 }
311 x += hhh; 286 x += hhh;
312 } 287 }
313 288
314 cross *= hhh; << 289 cross *=hhh;
315 cross = std::max(cross, 0.0); << 290 if(cross < 0.0) cross = 0.0;
316 return cross; 291 return cross;
317 } 292 }
318 293
319 //....oooOO0OOooo........oooOO0OOooo........oo 294 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
320 295
321 G4double G4MuPairProductionModel::ComputeDMicr 296 G4double G4MuPairProductionModel::ComputeDMicroscopicCrossSection(
322 G4d 297 G4double tkin,
323 G4d 298 G4double Z,
324 G4d 299 G4double pairEnergy)
325 // Calculates the differential (D) microscopi << 300 // Calculates the differential (D) microscopic cross section
326 // using the cross section formula of R.P. Kok << 301 // using the cross section formula of R.P. Kokoulin (18/01/98)
327 // Code modified by R.P. Kokoulin, V.N. Ivanch << 302 {
328 { << 303 static const G4double
329 static const G4double bbbtf= 183. ; << 304 xgi[] ={ 0.0199,0.1017,0.2372,0.4083,0.5917,0.7628,0.8983,0.9801 };
330 static const G4double bbbh = 202.4 ; <<
331 static const G4double g1tf = 1.95e-5 ; <<
332 static const G4double g2tf = 5.3e-5 ; <<
333 static const G4double g1h = 4.4e-5 ; <<
334 static const G4double g2h = 4.8e-5 ; <<
335 305
336 if (pairEnergy <= minPairEnergy) << 306 static const G4double
337 return 0.0; << 307 wgi[] ={ 0.0506,0.1112,0.1569,0.1813,0.1813,0.1569,0.1112,0.0506 };
338 308
339 G4double totalEnergy = tkin + particleMass; << 309 G4double cross = 0.;
340 G4double residEnergy = totalEnergy - pairEn <<
341 310
342 if (residEnergy <= 0.75*sqrte*z13*particleMa << 311 G4double particleMass = (G4MuonPlus::MuonPlus())->GetPDGMass();
343 return 0.0; << 312 G4double totalEnergy = tkin + particleMass;
>> 313 G4double energyLoss = totalEnergy - pairEnergy;
>> 314 G4double a = 6.*particleMass*particleMass/(totalEnergy*energyLoss) ;
>> 315 G4double b = 4.*electron_mass_c2/pairEnergy;
>> 316
>> 317 G4double tmn = (b+2.*a*(1.-b))/(1.+(1.-a)*sqrt(1.-b));
>> 318 if(tmn <= 0.) return cross;
>> 319 tmn = log(tmn);
344 320
345 G4double a0 = 1.0 / (totalEnergy * residEner << 321 // Gaussian integration in ln(1-ro) ( with 8 points)
346 G4double alf = 4.0 * electron_mass_c2 / pair << 322 for (G4int i=0; i<8; i++)
347 G4double rt = std::sqrt(1.0 - alf); << 323 {
348 G4double delta = 6.0 * particleMass * partic << 324 G4double ro = 1.-exp(tmn*xgi[i]);
349 G4double tmnexp = alf/(1.0 + rt) + delta*rt; << 325 cross += wgi[i]*(1.-ro)*ComputeDDMicroscopicCrossSection(
>> 326 tkin,Z,pairEnergy,ro);
>> 327 }
>> 328 cross *= -tmn;
>> 329 return cross;
>> 330 }
350 331
351 if(tmnexp >= 1.0) { return 0.0; } << 332 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
352 333
353 G4double tmn = G4Log(tmnexp); << 334 G4double G4MuPairProductionModel::ComputeDDMicroscopicCrossSection(
>> 335 G4double tkin,
>> 336 G4double Z,
>> 337 G4double pairEnergy,
>> 338 G4double asymmetry)
>> 339 // Calculates the differential (D) microscopic cross section
>> 340 // using the cross section formula of R.P. Kokoulin (18/01/98)
>> 341 {
>> 342 static const G4double sqrte = sqrt(exp(1.)) ;
>> 343
>> 344 G4double bbbtf= 183. ;
>> 345 G4double bbbh = 202.4 ;
>> 346 G4double g1tf = 1.95e-5 ;
>> 347 G4double g2tf = 5.3e-5 ;
>> 348 G4double g1h = 4.4e-5 ;
>> 349 G4double g2h = 4.8e-5 ;
354 350
355 G4double massratio = particleMass/CLHEP::ele << 351 G4double particleMass = (G4MuonPlus::MuonPlus())->GetPDGMass();
356 G4double massratio2 = massratio*massratio; << 352 G4double totalEnergy = tkin + particleMass;
357 G4double inv_massratio2 = 1.0 / massratio2; << 353 G4double energyLoss = totalEnergy - pairEnergy;
>> 354 G4double massratio = particleMass/electron_mass_c2 ;
>> 355 G4double massratio2 = massratio*massratio ;
>> 356
>> 357 G4double z13 = pow(Z,0.333333333);
>> 358 G4double z23 = z13*z13 ;
>> 359
>> 360 G4double c3 = 3.*sqrte*particleMass/4. ;
>> 361
>> 362 G4double DDCrossSection = 0. ;
>> 363 if (energyLoss <= c3*z13) return DDCrossSection;
>> 364
>> 365 G4double c7 = 4.*electron_mass_c2;
>> 366 G4double c8 = 6.*particleMass*particleMass;
>> 367 G4double alf = c7/pairEnergy;
>> 368 G4double a3 = 1. - alf;
>> 369 if (a3 <= 0.) return DDCrossSection;
358 370
359 // zeta calculation << 371 // zeta calculation
360 G4double bbb,g1,g2; << 372 G4double bbb,g1,g2,zeta1,zeta2,zeta,z2;
361 if( Z < 1.5 ) { bbb = bbbh ; g1 = g1h ; g2 = 373 if( Z < 1.5 ) { bbb = bbbh ; g1 = g1h ; g2 = g2h ; }
362 else { bbb = bbbtf; g1 = g1tf; g2 = 374 else { bbb = bbbtf; g1 = g1tf; g2 = g2tf; }
363 << 375 zeta1 = 0.073 * log(totalEnergy/(particleMass+g1*z23*totalEnergy))-0.26 ;
364 G4double zeta = 0.0; << 376 if ( zeta1 > 0.)
365 G4double z1exp = totalEnergy / (particleMass <<
366 <<
367 // 35.221047195922 is the root of zeta1(x) = <<
368 // condition below is the same as zeta1 > 0. <<
369 if (z1exp > 35.221047195922) <<
370 { 377 {
371 G4double z2exp = totalEnergy / (particleMa << 378 zeta2 = 0.058*log(totalEnergy/(particleMass+g2*z13*totalEnergy))-0.14 ;
372 zeta = (0.073 * G4Log(z1exp) - 0.26) / (0. << 379 zeta = zeta1/zeta2 ;
>> 380 }
>> 381 else
>> 382 {
>> 383 zeta = 0. ;
373 } 384 }
374 385
375 G4double z2 = Z*(Z+zeta); << 386 z2 = Z*(Z+zeta);
376 G4double screen0 = 2.*electron_mass_c2*sqrte <<
377 G4double beta = 0.5*pairEnergy*pairEnergy*a0 <<
378 G4double xi0 = 0.5*massratio2*beta; <<
379 <<
380 // Gaussian integration in ln(1-ro) ( with 8 <<
381 G4double rho[NINTPAIR]; <<
382 G4double rho2[NINTPAIR]; <<
383 G4double xi[NINTPAIR]; <<
384 G4double xi1[NINTPAIR]; <<
385 G4double xii[NINTPAIR]; <<
386 387
387 for (G4int i = 0; i < NINTPAIR; ++i) << 388 G4double screen0 = 2.*electron_mass_c2*sqrte*bbb/(z13*pairEnergy);
>> 389 G4double a0 = totalEnergy*energyLoss;
>> 390 G4double a1 = pairEnergy*pairEnergy/a0;
>> 391 G4double bet = 0.5*a1;
>> 392 G4double xi0 = 0.25*massratio2*a1;
>> 393 G4double del = c8/a0;
>> 394
>> 395 G4double romin = 0. ;
>> 396 G4double romax = (1.-del)*sqrt(1.-c7/pairEnergy);
>> 397
>> 398 if((asymmetry < romin) || (asymmetry > romax)) return DDCrossSection;
>> 399
>> 400 G4double a4 = 1.-asymmetry ;
>> 401 G4double a5 = a4*(2.-a4) ;
>> 402 G4double a6 = 1.-a5 ;
>> 403 G4double a7 = 1.+a6 ;
>> 404 G4double a9 = 3.+a6 ;
>> 405 G4double xi = xi0*a5 ;
>> 406 G4double xii = 1./xi ;
>> 407 G4double xi1 = 1.+xi ;
>> 408 G4double screen = screen0*xi1/a5 ;
>> 409
>> 410 G4double yeu = 5.-a6+4.*bet*a7 ;
>> 411 G4double yed = 2.*(1.+3.*bet)*log(3.+xii)-a6-a1*(2.-a6) ;
>> 412 G4double yel = 1.+yeu/yed ;
>> 413 G4double ale=log(bbb/z13*sqrt(xi1*yel)/(1.+screen*yel)) ;
>> 414 G4double cre = 0.5*log(1.+2.25/(massratio2*z23)*xi1*yel) ;
>> 415 G4double be;
>> 416 if (xi <= 1.e3) be = ((2.+a6)*(1.+bet)+xi*a9)*log(1.+xii)+(a5-bet)/xi1-a9;
>> 417 else be = (3.-a6+a1*a7)/(2*xi);
>> 418 G4double fe = (ale-cre)*be;
>> 419 if ( fe < 0.) fe = 0. ;
>> 420
>> 421 G4double ymu = 4.+a6 +3.*bet*a7 ;
>> 422 G4double ymd = a7*(1.5+a1)*log(3.+xi)+1.-1.5*a6 ;
>> 423 G4double ym1 = 1.+ymu/ymd ;
>> 424 G4double alm_crm = log(bbb*massratio/(1.5*z23*(1.+screen*ym1)));
>> 425 G4double a10,bm;
>> 426 if ( xi >= 1.e-3)
388 { 427 {
389 rho[i] = G4Exp(tmn*xgi[i]) - 1.0; // rho = << 428 a10 = (1.+a1)*a5 ;
390 rho2[i] = rho[i] * rho[i]; << 429 bm = (a7*(1.+1.5*bet)-a10*xii)*log(xi1)+xi*(a5-bet)/xi1+a10;
391 xi[i] = xi0*(1.0-rho2[i]); <<
392 xi1[i] = 1.0 + xi[i]; <<
393 xii[i] = 1.0 / xi[i]; <<
394 } 430 }
>> 431 else
>> 432 bm = (5.-a6+bet*a9)*(xi/2.);
>> 433
>> 434 G4double fm = alm_crm*bm;
>> 435 if ( fm < 0.) fm = 0. ;
395 436
396 G4double ye1[NINTPAIR]; << 437 DDCrossSection = (fe+fm/massratio2);
397 G4double ym1[NINTPAIR]; <<
398 438
399 G4double b40 = 4.0 * beta; << 439 DDCrossSection *= 4.*fine_structure_const*fine_structure_const
400 G4double b62 = 6.0 * beta + 2.0; << 440 *classic_electr_radius*classic_electr_radius/(3.*pi);
401 441
402 for (G4int i = 0; i < NINTPAIR; ++i) << 442 DDCrossSection *= z2*energyLoss/(totalEnergy*pairEnergy);
403 { <<
404 G4double yeu = (b40 + 5.0) + (b40 - 1.0) * <<
405 G4double yed = b62*G4Log(3.0 + xii[i]) + ( <<
406 443
407 G4double ymu = b62 * (1.0 + rho2[i]) + 6.0 << 444 return DDCrossSection;
408 G4double ymd = (b40 + 3.0)*(1.0 + rho2[i]) <<
409 + 2.0 - 3.0 * rho2[i]; <<
410 <<
411 ye1[i] = 1.0 + yeu / yed; <<
412 ym1[i] = 1.0 + ymu / ymd; <<
413 } <<
414 <<
415 G4double be[NINTPAIR]; <<
416 G4double bm[NINTPAIR]; <<
417 <<
418 for(G4int i = 0; i < NINTPAIR; ++i) { <<
419 if(xi[i] <= 1000.0) { <<
420 be[i] = ((2.0 + rho2[i])*(1.0 + beta) + <<
421 xi[i]*(3.0 + rho2[i]))*G4Log(1.0 + xi <<
422 (1.0 - rho2[i] - beta)/xi1[i] - (3.0 + rho2[ <<
423 } else { <<
424 be[i] = 0.5*(3.0 - rho2[i] + 2.0*beta*(1 <<
425 } <<
426 445
427 if(xi[i] >= 0.001) { << 446 }
428 G4double a10 = (1.0 + 2.0 * beta) * (1.0 <<
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 } <<
435 447
436 G4double sum = 0.0; << 448 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
437 449
438 for (G4int i = 0; i < NINTPAIR; ++i) { << 450 G4double
439 G4double screen = screen0*xi1[i]/(1.0 - rh << 451 G4MuPairProductionModel::CrossSection(const G4MaterialCutsCouple* couple,
440 G4double ale = G4Log(bbb/z13*std::sqrt(xi1 << 452 const G4ParticleDefinition*,
441 G4double cre = 0.5*G4Log(1. + 2.25*z23*xi1 << 453 G4double kineticEnergy,
>> 454 G4double cutEnergy, G4double maxEnergy)
>> 455 {
>> 456 G4double cross = 0.0;
442 457
443 G4double fe = (ale-cre)*be[i]; << 458 G4double tmax = std::min(maxEnergy, kineticEnergy);
444 fe = std::max(fe, 0.0); << 459 if (cutEnergy >= tmax) return cross;
445 460
446 G4double alm_crm = G4Log(bbb*massratio/(1. << 461 const G4Material* material = couple->GetMaterial();
447 G4double fm = std::max(alm_crm*bm[i], 0.0) << 462 const G4ElementVector* theElementVector = material->GetElementVector();
>> 463 const G4double* theAtomNumDensityVector=material->GetAtomicNumDensityVector();
448 464
449 sum += wgi[i]*(1.0 + rho[i])*(fe + fm); << 465 for (size_t i=0; i<material->GetNumberOfElements(); i++) {
450 } << 466 G4double Z = (*theElementVector)[i]->GetZ();
>> 467 G4double cr = ComputeMicroscopicCrossSection(kineticEnergy, Z, cutEnergy);
451 468
452 return -tmn*sum*factorForCross*z2*residEnerg << 469 if (maxEnergy < kineticEnergy) {
>> 470 cr -= ComputeMicroscopicCrossSection(kineticEnergy, Z, maxEnergy);
>> 471 }
>> 472 cross += theAtomNumDensityVector[i] * cr;
>> 473 }
>> 474 return cross;
453 } 475 }
454 476
455 //....oooOO0OOooo........oooOO0OOooo........oo 477 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
456 478
457 G4double G4MuPairProductionModel::ComputeCross << 479 G4DataVector* G4MuPairProductionModel::ComputePartialSumSigma(
458 con << 480 const G4Material* material,
459 << 481 G4double kineticEnergy,
460 << 482 G4double cut)
461 << 483
462 << 484 // Build the table of cross section per element.
>> 485 // This table is used by DoIt to select randomly an element in the material.
463 { 486 {
>> 487 G4int nElements = material->GetNumberOfElements();
>> 488 const G4ElementVector* theElementVector = material->GetElementVector();
>> 489 const G4double* theAtomNumDensityVector=material->GetAtomicNumDensityVector();
>> 490
>> 491 G4DataVector* dv = new G4DataVector();
>> 492
464 G4double cross = 0.0; 493 G4double cross = 0.0;
465 if (kineticEnergy <= lowestKinEnergy) { retu <<
466 494
467 G4double maxPairEnergy = MaxSecondaryEnergyF << 495 for (G4int i=0; i<nElements; i++ ) {
468 G4double tmax = std::min(maxEnergy, maxPairE << 496 G4double Z = (*theElementVector)[i]->GetZ();
469 G4double cut = std::max(cutEnergy, minPairE << 497 cross += theAtomNumDensityVector[i] * ComputeMicroscopicCrossSection(
470 if (cut >= tmax) { return cross; } << 498 kineticEnergy, Z, cut);
471 << 499 dv->push_back(cross);
472 cross = ComputeMicroscopicCrossSection(kinet <<
473 if(tmax < kineticEnergy) { <<
474 cross -= ComputeMicroscopicCrossSection(ki <<
475 } 500 }
476 return cross; << 501 return dv;
477 } 502 }
478 503
479 //....oooOO0OOooo........oooOO0OOooo........oo 504 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
480 505
481 void G4MuPairProductionModel::MakeSamplingTabl 506 void G4MuPairProductionModel::MakeSamplingTables()
482 { 507 {
483 G4double factore = G4Exp(G4Log(emax/emin)/G4 << 508 static const G4double sqrte = sqrt(exp(1.)) ;
>> 509 G4double particleMass = (G4MuonPlus::MuonPlus())->GetPDGMass();
484 510
485 for (G4int iz=0; iz<NZDATPAIR; ++iz) { << 511 for (G4int iz=0; iz<nzdat; iz++)
>> 512 {
>> 513 G4double atomicNumber = zdat[iz];
>> 514 G4double z13 = exp(log(atomicNumber)/3.) ;
486 515
487 G4double Z = ZDATPAIR[iz]; << 516 for (G4int it=0; it<ntdat; it++)
488 G4Physics2DVector* pv = new G4Physics2DVec << 517 {
489 G4double kinEnergy = emin; << 518 G4double kineticEnergy = tdat[it];
490 << 519 G4double maxPairEnergy = kineticEnergy+particleMass*(1.-0.75*sqrte*z13) ;
491 for (std::size_t it=0; it<=nbine; ++it) { << 520
492 << 521 G4double CrossSection = 0.0 ;
493 pv->PutY(it, G4Log(kinEnergy/CLHEP::MeV) << 522
494 G4double maxPairEnergy = MaxSecondaryEne << 523 G4double ymin = -5. ;
495 /* << 524 G4double ymax = 0. ;
496 G4cout << "it= " << it << " E= " << kinE << 525 G4double dy = (ymax-ymin)/NBIN ;
497 << " " << particle->GetParticleN << 526
498 << " maxE= " << maxPairEnergy << << 527 G4double y = ymin - 0.5*dy ;
499 << " ymin= " << ymin << G4endl; << 528 G4double yy = ymin - dy ;
500 */ << 529 G4double x = exp(y);
501 G4double coef = G4Log(minPairEnergy/kinE << 530 G4double fac = exp(dy);
502 G4double ymax = G4Log(maxPairEnergy/kinE << 531 G4double dx = exp(yy)*(fac - 1.0);
503 G4double fac = (ymax - ymin)/dy; << 532
504 std::size_t imax = (std::size_t)fac; << 533 if (maxPairEnergy > minPairEnergy) {
505 fac -= (G4double)imax; << 534 G4double c = log(maxPairEnergy/minPairEnergy);
506 << 535 for (G4int i=0 ; i<NBIN; i++)
507 G4double xSec = 0.0; << 536 {
508 G4double x = ymin; << 537 y += dy ;
509 /* << 538 x *= fac;
510 G4cout << "Z= " << currentZ << " z13= " << 539 dx*= fac;
511 << " mE= " << maxPairEnergy << " << 540 G4double ep = minPairEnergy*exp(c*x) ;
512 << " dy= " << dy << " c= " << co << 541 CrossSection += ep*dx*ComputeDMicroscopicCrossSection(
513 */ << 542 kineticEnergy, atomicNumber, ep);
514 // start from zero << 543 ya[i] = y;
515 pv->PutValue(0, it, 0.0); << 544 proba[iz][it][i] = CrossSection;
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 } 545 }
536 pv->PutValue(i + 1, it, xSec); << 546 } else {
537 x += dy; << 547 for (G4int i=0 ; i<NBIN; i++)
538 } << 548 {
539 kinEnergy *= factore; << 549 y += dy ;
>> 550 ya[i] = y ;
>> 551 proba[iz][it][i] = 0.0 ;
>> 552 }
>> 553 }
>> 554
>> 555 ya[NBIN]=0. ;
>> 556
>> 557 proba[iz][it][NBIN] = CrossSection;
540 558
541 // to avoid precision lost << 559 if(CrossSection > 0.)
542 if(it+1 == nbine) { kinEnergy = emax; } << 560 {
>> 561 for(G4int ib=0; ib<=NBIN; ib++)
>> 562 {
>> 563 proba[iz][it][ib] /= CrossSection ;
>> 564
>> 565 }
>> 566 }
543 } 567 }
544 fElementData->InitialiseForElement(iz, pv) <<
545 } 568 }
>> 569 samplingTablesAreFilled = true;
546 } 570 }
547 571
548 //....oooOO0OOooo........oooOO0OOooo........oo 572 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
549 573
550 void G4MuPairProductionModel::SampleSecondarie << 574 G4DynamicParticle* G4MuPairProductionModel::SampleSecondary(
551 std::vector<G4Dy << 575 const G4MaterialCutsCouple*,
552 const G4Material << 576 const G4DynamicParticle*,
553 const G4DynamicP << 577 G4double,
554 G4double tmin, << 578 G4double)
555 G4double tmax) << 579 {
556 { << 580 return 0;
557 G4double kinEnergy = aDynamicParticle->GetKi << 581 }
558 //G4cout << "------- G4MuPairProductionModel << 582
559 // << kinEnergy << " " << 583 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
560 // << aDynamicParticle->GetDefinitio << 584
561 G4double totalEnergy = kinEnergy + particl << 585 std::vector<G4DynamicParticle*>* G4MuPairProductionModel::SampleSecondaries(
562 G4double totalMomentum = << 586 const G4MaterialCutsCouple* couple,
563 std::sqrt(kinEnergy*(kinEnergy + 2.0*parti << 587 const G4DynamicParticle* aDynamicParticle,
564 << 588 G4double minEnergy,
565 G4ThreeVector partDirection = aDynamicPartic << 589 G4double maxEnergy)
566 << 590 {
567 // select randomly one element constituing t << 591 static const G4double esq = sqrt(exp(1.));
568 const G4Element* anElement = SelectRandomAto << 592 G4double kineticEnergy = aDynamicParticle->GetKineticEnergy();
569 << 593 G4double particleMass = aDynamicParticle->GetDefinition()->GetPDGMass();
570 // define interval of energy transfer << 594 G4ParticleMomentum ParticleDirection =
571 G4double maxPairEnergy = MaxSecondaryEnergyF << 595 aDynamicParticle->GetMomentumDirection();
572 << 596
573 G4double maxEnergy = std::min(tmax, maxPairE << 597 // select randomly one element constituing the material
574 G4double minEnergy = std::max(tmin, minPairE << 598 const G4Element* anElement = SelectRandomAtom(couple);
575 << 599
576 if (minEnergy >= maxEnergy) { return; } << 600 // limits of the energy sampling
577 //G4cout << "emin= " << minEnergy << " emax= << 601 G4double totalEnergy = kineticEnergy + particleMass ;
578 // << " minPair= " << minPairEnergy << " max << 602 //G4double TotalMomentum = sqrt(KineticEnergy*(TotalEnergy+particleMass)) ;
579 // << " ymin= " << ymin << " dy= " << dy << 603 G4double Z3 = anElement->GetIonisation()->GetZ3() ;
580 << 604 G4double maxPairEnergy = totalEnergy-0.75*esq*particleMass*Z3 ;
581 G4double coeff = G4Log(minPairEnergy/kinEner << 605 if(maxPairEnergy > maxEnergy) maxPairEnergy = maxEnergy;
582 << 606
583 // compute limits << 607 // check against insufficient energy
584 G4double yymin = G4Log(minEnergy/kinEnergy)/ << 608 if(minEnergy >= maxPairEnergy) return 0;
585 G4double yymax = G4Log(maxEnergy/kinEnergy)/ << 609
586 << 610 // sample e-e+ energy, pair energy first
587 //G4cout << "yymin= " << yymin << " yymax= << 611 G4double PairEnergy,x,yc,y ;
588 << 612 // G4int iZ,iT;
589 // units should not be used, bacause table w << 613 G4int iy ;
590 G4double logTkin = G4Log(kinEnergy/CLHEP::Me << 614
591 << 615 // select sampling table ;
592 // sample e-e+ energy, pair energy first << 616 G4double lnZ = log(anElement->GetZ()) ;
593 << 617 G4double delmin = 1.e10 ;
594 // select sample table via Z << 618 G4double del ;
595 G4int iz1(0), iz2(0); << 619 G4int izz = 0;
596 for (G4int iz=0; iz<NZDATPAIR; ++iz) { << 620 G4int itt = 0;
597 if(currentZ == ZDATPAIR[iz]) { << 621 G4int NBINminus1 = NBIN-1;
598 iz1 = iz2 = iz; << 622 for (G4int iz=0; iz<nzdat; iz++)
599 break; << 623 {
600 } else if(currentZ < ZDATPAIR[iz]) { << 624 del = abs(lnZ-log(zdat[iz])) ;
601 iz2 = iz; << 625 if(del<delmin)
602 if(iz > 0) { iz1 = iz-1; } << 626 {
603 else { iz1 = iz2; } << 627 delmin=del ;
604 break; << 628 izz=iz ;
605 } << 629 }
606 } << 630 }
607 if (0 == iz1) { iz1 = iz2 = NZDATPAIR-1; } << 631 delmin = 1.e10 ;
608 << 632 for (G4int it=0; it<ntdat; it++)
609 G4double pairEnergy = 0.0; << 633 {
610 G4int count = 0; << 634 del = abs(log(kineticEnergy)-log(tdat[it])) ;
611 //G4cout << "start loop Z1= " << iz1 << " Z2 << 635 if(del<delmin)
612 do { << 636 {
613 ++count; << 637 delmin=del;
614 // sampling using only one random number << 638 itt=it ;
615 G4double rand = G4UniformRand(); << 639 }
616 << 640 }
617 G4double x = FindScaledEnergy(iz1, rand, l << 641
618 if(iz1 != iz2) { << 642 if( minEnergy <= minPairEnergy)
619 G4double x2 = FindScaledEnergy(iz2, rand << 643 iy = 0 ;
620 G4double lz1= nist->GetLOGZ(ZDATPAIR[iz1 << 644 else
621 G4double lz2= nist->GetLOGZ(ZDATPAIR[iz2 << 645 {
622 //G4cout << count << ". x= " << x << " << 646 G4double xc = log(minEnergy/minPairEnergy)/log(maxPairEnergy/minPairEnergy);
623 // << " Z1= " << iz1 << " Z2 << 647 yc = log(xc) ;
624 x += (x2 - x)*(lnZ - lz1)/(lz2 - lz1); << 648 iy = -1 ;
625 } << 649 do { iy += 1;} while ((ya[iy] < yc )&&(iy < NBINminus1));
626 //G4cout << "x= " << x << " coeff= " << c << 650 }
627 pairEnergy = kinEnergy*G4Exp(x*coeff); << 651
628 << 652 G4double norm = proba[izz][itt][iy];
629 // Loop checking, 03-Aug-2015, Vladimir Iv << 653
630 } while((pairEnergy < minEnergy || pairEnerg << 654 G4double r = norm+G4UniformRand()*(1.-norm);
>> 655
>> 656 iy -= 1;
>> 657 do { iy += 1;} while ((proba[izz][itt][iy] < r)&&(iy < NBINminus1));
>> 658
>> 659 //sampling is uniformly in y in the bin
>> 660 if( iy < NBIN ) y = ya[iy] + G4UniformRand() * ( ya[iy+1] - ya[iy]);
>> 661 else y = ya[iy];
>> 662
>> 663 x = exp(y);
>> 664
>> 665 PairEnergy = minPairEnergy*exp(x*log(maxPairEnergy/minPairEnergy));
>> 666
>> 667 // sample r=(E+-E-)/PairEnergy ( uniformly .....)
>> 668 G4double rmax = (1.-6.*particleMass*particleMass/(totalEnergy*
>> 669 (totalEnergy-PairEnergy)))
>> 670 *sqrt(1.-minPairEnergy/PairEnergy);
>> 671 r = rmax * (-1.+2.*G4UniformRand()) ;
>> 672
>> 673 // compute energies from PairEnergy,r
>> 674 G4double ElectronEnergy=(1.-r)*PairEnergy/2. ;
>> 675 G4double PositronEnergy=(1.+r)*PairEnergy/2. ;
>> 676
>> 677 // angles of the emitted particles ( Z - axis along the parent particle)
>> 678 // (mean theta for the moment)
>> 679 G4double Teta = electron_mass_c2/totalEnergy ;
>> 680
>> 681 G4double Phi = twopi * G4UniformRand() ;
>> 682 G4double dirx = sin(Teta)*cos(Phi) , diry = sin(Teta)*sin(Phi) ,
>> 683 dirz = cos(Teta) ;
>> 684
>> 685 G4double ElectronMomentum , PositronMomentum ;
>> 686 //G4double finalPx,finalPy,finalPz ;
>> 687 G4double ElectKineEnergy = ElectronEnergy - electron_mass_c2 ;
>> 688
>> 689 ElectronMomentum = sqrt(ElectKineEnergy*(ElectronEnergy+electron_mass_c2));
>> 690 G4ThreeVector ElectDirection ( dirx, diry, dirz );
>> 691 ElectDirection.rotateUz(ParticleDirection);
>> 692
>> 693 // create G4DynamicParticle object for the particle1
>> 694 G4DynamicParticle* aParticle1= new G4DynamicParticle();
>> 695 aParticle1->SetDefinition(G4Electron::Electron());
>> 696 aParticle1->SetMomentumDirection(ElectDirection);
>> 697 aParticle1->SetKineticEnergy(ElectKineEnergy);
>> 698
>> 699
>> 700 G4double PositKineEnergy = PositronEnergy - electron_mass_c2 ;
>> 701 PositronMomentum = sqrt(PositKineEnergy*(PositronEnergy+electron_mass_c2));
>> 702
>> 703 G4ThreeVector PositDirection ( -dirx, -diry, dirz );
>> 704 PositDirection.rotateUz(ParticleDirection);
>> 705
>> 706 // create G4DynamicParticle object for the particle2
>> 707 G4DynamicParticle* aParticle2= new G4DynamicParticle();
>> 708 aParticle2->SetDefinition(G4Positron::Positron());
>> 709 aParticle2->SetMomentumDirection(PositDirection);
>> 710 aParticle2->SetKineticEnergy(PositKineEnergy);
631 711
632 //G4cout << "## pairEnergy(GeV)= " << pairEn <<
633 // << " Etot(GeV)= " << totalEnergy/ <<
634 712
635 // sample r=(E+-E-)/pairEnergy ( uniformly << 713 std::vector<G4DynamicParticle*>* vdp = new std::vector<G4DynamicParticle*>;
636 G4double rmax = <<
637 (1.-6.*particleMass*particleMass/(totalEne <<
638 *std::sqrt(1.-minPairEnergy/pairEnergy); <<
639 G4double r = rmax * (-1.+2.*G4UniformRand()) <<
640 <<
641 // compute energies from pairEnergy,r <<
642 G4double eEnergy = (1.-r)*pairEnergy*0.5; <<
643 G4double pEnergy = pairEnergy - eEnergy; <<
644 <<
645 // Sample angles <<
646 G4ThreeVector eDirection, pDirection; <<
647 // <<
648 GetAngularDistribution()->SamplePairDirectio <<
649 <<
650 <<
651 // create G4DynamicParticle object for e+e- <<
652 eEnergy = std::max(eEnergy - CLHEP::electron <<
653 pEnergy = std::max(pEnergy - CLHEP::electron <<
654 auto aParticle1 = new G4DynamicParticle(theE <<
655 auto aParticle2 = new G4DynamicParticle(theP <<
656 // Fill output vector <<
657 vdp->push_back(aParticle1); 714 vdp->push_back(aParticle1);
658 vdp->push_back(aParticle2); 715 vdp->push_back(aParticle2);
659 716
660 // primary change << 717 return vdp;
661 kinEnergy -= pairEnergy; <<
662 partDirection *= totalMomentum; <<
663 partDirection -= (aParticle1->GetMomentum() <<
664 partDirection = partDirection.unit(); <<
665 <<
666 // if energy transfer is higher than thresho <<
667 // then stop tracking the primary particle a <<
668 if (pairEnergy > SecondaryThreshold()) { <<
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 } 718 }
679 719
680 //....oooOO0OOooo........oooOO0OOooo........oo 720 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
681 721
682 G4double << 722 const G4Element* G4MuPairProductionModel::SelectRandomAtom(
683 G4MuPairProductionModel::FindScaledEnergy(G4in << 723 const G4MaterialCutsCouple* couple) const
684 G4double logTkin, <<
685 G4double yymin, G4double yymax) <<
686 { 724 {
687 G4double res = yymin; << 725 // select randomly 1 element within the material
688 G4Physics2DVector* pv = fElementData->GetEle <<
689 if (nullptr != pv) { <<
690 G4double pmin = pv->Value(yymin, logTkin); <<
691 G4double pmax = pv->Value(yymax, logTkin); <<
692 G4double p0 = pv->Value(0.0, logTkin); <<
693 if(p0 <= 0.0) { DataCorrupted(ZDATPAIR[iz] <<
694 else { res = pv->FindLinearX((pmin + rand* <<
695 } else { <<
696 DataCorrupted(ZDATPAIR[iz], logTkin); <<
697 } <<
698 return res; <<
699 } <<
700 726
701 //....oooOO0OOooo........oooOO0OOooo........oo << 727 const G4Material* material = couple->GetMaterial();
702 << 728 G4int nElements = material->GetNumberOfElements();
703 void G4MuPairProductionModel::DataCorrupted(G4 << 729 const G4ElementVector* theElementVector = material->GetElementVector();
704 { << 730 if (nElements == 1) return (*theElementVector)[0];
705 G4ExceptionDescription ed; << 731 else if (nElements < 1) return 0;
706 ed << "G4ElementData is not properly initial <<
707 << " Ekin(MeV)= " << G4Exp(logTkin) <<
708 << " IsMasterThread= " << IsMaster() <<
709 << " Model " << GetName(); <<
710 G4Exception("G4MuPairProductionModel::()", " <<
711 } <<
712 <<
713 //....oooOO0OOooo........oooOO0OOooo........oo <<
714 732
715 void G4MuPairProductionModel::StoreTables() co << 733 G4DataVector* dv = partialSumSigma[couple->GetIndex()];
716 { << 734 G4double rval = G4UniformRand()*((*dv)[nElements-1]);
717 for (G4int iz=0; iz<NZDATPAIR; ++iz) { << 735 for (G4int i=0; i<nElements; i++) {
718 G4int Z = ZDATPAIR[iz]; << 736 if (rval <= (*dv)[i]) return (*theElementVector)[i];
719 G4Physics2DVector* pv = fElementData->GetE <<
720 if(nullptr == pv) { <<
721 DataCorrupted(Z, 1.0); <<
722 return; <<
723 } <<
724 std::ostringstream ss; <<
725 ss << "mupair/" << particle->GetParticleNa <<
726 std::ofstream outfile(ss.str()); <<
727 pv->Store(outfile); <<
728 } 737 }
>> 738 return (*theElementVector)[nElements-1];
729 } 739 }
730 740
731 //....oooOO0OOooo........oooOO0OOooo........oo 741 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
732 742
733 G4bool G4MuPairProductionModel::RetrieveTables <<
734 { <<
735 for (G4int iz=0; iz<NZDATPAIR; ++iz) { <<
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 } <<
748 return true; <<
749 } <<
750 743
751 //....oooOO0OOooo........oooOO0OOooo........oo <<
752 744