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27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class
30 // File name: G4PAIModel.cc
31 //
32 // Author: Vladimir.Grichine@cern.ch on base of V.Ivanchenko model interface
33 //
34 // Creation date: 05.10.2003
35 //
36 // Modifications:
37 //
38 // 17.08.04 V.Grichine, bug fixed for Tkin<=0 in SampleSecondary
39 // 16.08.04 V.Grichine, bug fixed in massRatio for DEDX, CrossSection,
40 // SampleSecondary
41 // 08.04.05 Major optimisation of internal interfaces (V.Ivantchenko)
42 // 26.07.09 Fixed logic to work with several materials (V.Ivantchenko)
43 // 21.11.10 V. Grichine verbose flag for protons and G4PAYySection to
44 // check sandia table
45 // 12.06.13 V. Grichine Bug fixed in SampleSecondaries for scaled Tkin
46 // (fMass -> proton_mass_c2)
47 // 19.08.13 V.Ivanchenko extract data handling to G4PAIModelData class
48 // added sharing of internal data between threads (MT migration)
49 //
50
51 #include "G4PAIModel.hh"
52
53 #include "G4SystemOfUnits.hh"
54 #include "G4PhysicalConstants.hh"
55 #include "G4Region.hh"
56 #include "G4MaterialCutsCouple.hh"
57 #include "G4MaterialTable.hh"
58 #include "G4RegionStore.hh"
59
60 #include "Randomize.hh"
61 #include "G4Electron.hh"
62 #include "G4Positron.hh"
63 #include "G4Poisson.hh"
64 #include "G4Step.hh"
65 #include "G4Material.hh"
66 #include "G4DynamicParticle.hh"
67 #include "G4ParticleDefinition.hh"
68 #include "G4ParticleChangeForLoss.hh"
69 #include "G4PAIModelData.hh"
70 #include "G4DeltaAngle.hh"
71
72 ////////////////////////////////////////////////////////////////////////
73
74 using namespace std;
75
76 G4PAIModel::G4PAIModel(const G4ParticleDefinition* p, const G4String& nam)
77 : G4VEmModel(nam),G4VEmFluctuationModel(nam),
78 fVerbose(0),
79 fModelData(nullptr),
80 fParticle(nullptr)
81 {
82 fElectron = G4Electron::Electron();
83 fPositron = G4Positron::Positron();
84
85 fParticleChange = nullptr;
86
87 if(p) { SetParticle(p); }
88 else { SetParticle(fElectron); }
89
90 // default generator
91 SetAngularDistribution(new G4DeltaAngle());
92 fLowestTcut = 12.5*CLHEP::eV;
93 }
94
95 ////////////////////////////////////////////////////////////////////////////
96
97 G4PAIModel::~G4PAIModel()
98 {
99 if(IsMaster()) { delete fModelData; }
100 }
101
102 ////////////////////////////////////////////////////////////////////////////
103
104 void G4PAIModel::Initialise(const G4ParticleDefinition* p,
105 const G4DataVector& cuts)
106 {
107 if(fVerbose > 1) {
108 G4cout<<"G4PAIModel::Initialise for "<<p->GetParticleName()<<G4endl;
109 }
110 SetParticle(p);
111 fParticleChange = GetParticleChangeForLoss();
112
113 if(IsMaster()) {
114
115 delete fModelData;
116 fMaterialCutsCoupleVector.clear();
117 if(fVerbose > 1) {
118 G4cout << "G4PAIModel instantiates data for " << p->GetParticleName()
119 << G4endl;
120 }
121 G4double tmin = LowEnergyLimit()*fRatio;
122 G4double tmax = HighEnergyLimit()*fRatio;
123 fModelData = new G4PAIModelData(tmin, tmax, fVerbose);
124
125 // Prepare initialization
126 const G4MaterialTable* theMaterialTable = G4Material::GetMaterialTable();
127 std::size_t numOfMat = G4Material::GetNumberOfMaterials();
128 std::size_t numRegions = fPAIRegionVector.size();
129
130 // protect for unit tests
131 if(0 == numRegions) {
132 G4Exception("G4PAIModel::Initialise()","em0106",JustWarning,
133 "no G4Regions are registered for the PAI model - World is used");
134 fPAIRegionVector.push_back(G4RegionStore::GetInstance()
135 ->GetRegion("DefaultRegionForTheWorld", false));
136 numRegions = 1;
137 }
138
139 if(fVerbose > 1) {
140 G4cout << "G4PAIModel is defined for " << numRegions << " regions "
141 << "; number of materials " << numOfMat << G4endl;
142 }
143 for(std::size_t iReg = 0; iReg<numRegions; ++iReg) {
144 const G4Region* curReg = fPAIRegionVector[iReg];
145 G4Region* reg = const_cast<G4Region*>(curReg);
146
147 for(std::size_t jMat = 0; jMat<numOfMat; ++jMat) {
148 G4Material* mat = (*theMaterialTable)[jMat];
149 const G4MaterialCutsCouple* cutCouple = reg->FindCouple(mat);
150 std::size_t n = fMaterialCutsCoupleVector.size();
151 if(nullptr != cutCouple) {
152 if(fVerbose > 1) {
153 G4cout << "Region <" << curReg->GetName() << "> mat <"
154 << mat->GetName() << "> CoupleIndex= "
155 << cutCouple->GetIndex()
156 << " " << p->GetParticleName()
157 << " cutsize= " << cuts.size() << G4endl;
158 }
159 // check if this couple is not already initialized
160 G4bool isnew = true;
161 if(0 < n) {
162 for(std::size_t i=0; i<n; ++i) {
163 G4cout << i << G4endl;
164 if(cutCouple == fMaterialCutsCoupleVector[i]) {
165 isnew = false;
166 break;
167 }
168 }
169 }
170 // initialise data banks
171 // G4cout << " isNew: " << isnew << " " << cutCouple << G4endl;
172 if(isnew) {
173 fMaterialCutsCoupleVector.push_back(cutCouple);
174 fModelData->Initialise(cutCouple, this);
175 }
176 }
177 }
178 }
179 InitialiseElementSelectors(p, cuts);
180 }
181 }
182
183 /////////////////////////////////////////////////////////////////////////
184
185 void G4PAIModel::InitialiseLocal(const G4ParticleDefinition*,
186 G4VEmModel* masterModel)
187 {
188 fModelData = static_cast<G4PAIModel*>(masterModel)->GetPAIModelData();
189 fMaterialCutsCoupleVector =
190 static_cast<G4PAIModel*>(masterModel)->GetVectorOfCouples();
191 SetElementSelectors(masterModel->GetElementSelectors());
192 }
193
194 //////////////////////////////////////////////////////////////////////////////
195
196 G4double G4PAIModel::MinEnergyCut(const G4ParticleDefinition*,
197 const G4MaterialCutsCouple*)
198 {
199 return fLowestTcut;
200 }
201
202 //////////////////////////////////////////////////////////////////////////////
203
204 G4double G4PAIModel::ComputeDEDXPerVolume(const G4Material*,
205 const G4ParticleDefinition* p,
206 G4double kineticEnergy,
207 G4double cutEnergy)
208 {
209 G4int coupleIndex = FindCoupleIndex(CurrentCouple());
210 if(0 > coupleIndex) { return 0.0; }
211
212 G4double cut = std::min(MaxSecondaryEnergy(p, kineticEnergy), cutEnergy);
213 G4double scaledTkin = kineticEnergy*fRatio;
214 G4double dedx = fChargeSquare*fModelData->DEDXPerVolume(coupleIndex, scaledTkin, cut);
215 return dedx;
216 }
217
218 /////////////////////////////////////////////////////////////////////////
219
220 G4double G4PAIModel::CrossSectionPerVolume( const G4Material*,
221 const G4ParticleDefinition* p,
222 G4double kineticEnergy,
223 G4double cutEnergy,
224 G4double maxEnergy )
225 {
226 G4int coupleIndex = FindCoupleIndex(CurrentCouple());
227 if(0 > coupleIndex) { return 0.0; }
228
229 G4double tmax = std::min(MaxSecondaryEnergy(p, kineticEnergy), maxEnergy);
230 if(tmax <= cutEnergy) { return 0.0; }
231
232 G4double scaledTkin = kineticEnergy*fRatio;
233 G4double xs = fChargeSquare*fModelData->CrossSectionPerVolume(coupleIndex,
234 scaledTkin, cutEnergy, tmax);
235 return xs;
236 }
237
238 ///////////////////////////////////////////////////////////////////////////
239 //
240 // It is analog of PostStepDoIt in terms of secondary electron.
241 //
242
243 void G4PAIModel::SampleSecondaries(std::vector<G4DynamicParticle*>* vdp,
244 const G4MaterialCutsCouple* matCC,
245 const G4DynamicParticle* dp,
246 G4double tmin,
247 G4double maxEnergy)
248 {
249 G4int coupleIndex = FindCoupleIndex(matCC);
250
251 //G4cout << "G4PAIModel::SampleSecondaries: coupleIndex= "<<coupleIndex<<G4endl;
252 if(0 > coupleIndex) { return; }
253
254 SetParticle(dp->GetDefinition());
255 G4double kineticEnergy = dp->GetKineticEnergy();
256
257 G4double tmax = MaxSecondaryEnergy(fParticle, kineticEnergy);
258 if(maxEnergy < tmax) { tmax = maxEnergy; }
259 if(tmin >= tmax) { return; }
260
261 G4ThreeVector direction= dp->GetMomentumDirection();
262 G4double scaledTkin = kineticEnergy*fRatio;
263 G4double totalEnergy = kineticEnergy + fMass;
264 G4double totalMomentum = sqrt(kineticEnergy*(totalEnergy+fMass));
265
266 G4double deltaTkin =
267 fModelData->SamplePostStepTransfer(coupleIndex, scaledTkin, tmin, tmax);
268
269 //G4cout<<"G4PAIModel::SampleSecondaries; deltaKIn = "<<deltaTkin/keV
270 // <<" keV "<< " Escaled(MeV)= " << scaledTkin << G4endl;
271
272 if( !(deltaTkin <= 0.) && !(deltaTkin > 0)) {
273 G4cout<<"G4PAIModel::SampleSecondaries; deltaKIn = "<<deltaTkin/keV
274 <<" keV "<< " Escaled(MeV)= " << scaledTkin << G4endl;
275 return;
276 }
277 if( deltaTkin <= 0.) { return; }
278
279 if( deltaTkin > tmax) { deltaTkin = tmax; }
280
281 const G4Element* anElement = SelectTargetAtom(matCC, fParticle, kineticEnergy,
282 dp->GetLogKineticEnergy());
283
284 G4int Z = anElement->GetZasInt();
285
286 auto deltaRay = new G4DynamicParticle(fElectron,
287 GetAngularDistribution()->SampleDirection(dp, deltaTkin,
288 Z, matCC->GetMaterial()),
289 deltaTkin);
290
291 // primary change
292 kineticEnergy -= deltaTkin;
293 G4ThreeVector dir = totalMomentum*direction - deltaRay->GetMomentum();
294 direction = dir.unit();
295 fParticleChange->SetProposedKineticEnergy(kineticEnergy);
296 fParticleChange->SetProposedMomentumDirection(direction);
297
298 vdp->push_back(deltaRay);
299 }
300
301 ///////////////////////////////////////////////////////////////////////
302
303 G4double G4PAIModel::SampleFluctuations(const G4MaterialCutsCouple* matCC,
304 const G4DynamicParticle* aParticle,
305 const G4double tcut,
306 const G4double,
307 const G4double step,
308 const G4double eloss)
309 {
310 G4int coupleIndex = FindCoupleIndex(matCC);
311 if(0 > coupleIndex) { return eloss; }
312
313 SetParticle(aParticle->GetDefinition());
314
315 /*
316 G4cout << "G4PAIModel::SampleFluctuations step(mm)= "<< step/mm
317 << " Eloss(keV)= " << eloss/keV << " in "
318 << matCC->Getmaterial()->GetName() << G4endl;
319 */
320
321 G4double Tkin = aParticle->GetKineticEnergy();
322 G4double scaledTkin = Tkin*fRatio;
323
324 G4double loss = fModelData->SampleAlongStepTransfer(coupleIndex, Tkin,
325 scaledTkin, tcut,
326 step*fChargeSquare);
327
328 // G4cout<<"PAIModel AlongStepLoss = "<<loss/keV<<" keV, on step = "
329 //<<step/mm<<" mm"<<G4endl;
330 return loss;
331
332 }
333
334 //////////////////////////////////////////////////////////////////////
335 //
336 // Returns the statistical estimation of the energy loss distribution variance
337 //
338
339
340 G4double G4PAIModel::Dispersion( const G4Material* material,
341 const G4DynamicParticle* aParticle,
342 const G4double tcut,
343 const G4double tmax,
344 const G4double step )
345 {
346 G4double particleMass = aParticle->GetMass();
347 G4double electronDensity = material->GetElectronDensity();
348 G4double kineticEnergy = aParticle->GetKineticEnergy();
349 G4double q = aParticle->GetCharge()/eplus;
350 G4double etot = kineticEnergy + particleMass;
351 G4double beta2 = kineticEnergy*(kineticEnergy + 2.0*particleMass)/(etot*etot);
352 G4double siga = (tmax/beta2 - 0.5*tcut) * twopi_mc2_rcl2 * step
353 * electronDensity * q * q;
354
355 return siga;
356 }
357
358 /////////////////////////////////////////////////////////////////////
359
360 G4double G4PAIModel::MaxSecondaryEnergy( const G4ParticleDefinition* p,
361 G4double kinEnergy)
362 {
363 SetParticle(p);
364 G4double tmax = kinEnergy;
365 if(p == fElectron) { tmax *= 0.5; }
366 else if(p != fPositron) {
367 G4double ratio= electron_mass_c2/fMass;
368 G4double gamma= kinEnergy/fMass + 1.0;
369 tmax = 2.0*electron_mass_c2*(gamma*gamma - 1.) /
370 (1. + 2.0*gamma*ratio + ratio*ratio);
371 }
372 return tmax;
373 }
374
375 ///////////////////////////////////////////////////////////////
376
377 void G4PAIModel::DefineForRegion(const G4Region* r)
378 {
379 fPAIRegionVector.push_back(r);
380 }
381
382 ///////////////////////////////////////////////////////////////
383
384