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28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4EmSaturation
33 //
34 // Author: Vladimir Ivanchenko
35 //
36 // Creation date: 18.02.2008
37 //
38 // Modifications:
39 //
40 // -------------------------------------------------------------
41
42 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
43 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
44
45 #include "G4EmSaturation.hh"
46 #include "G4PhysicalConstants.hh"
47 #include "G4SystemOfUnits.hh"
48 #include "G4LossTableManager.hh"
49 #include "G4NistManager.hh"
50 #include "G4Material.hh"
51 #include "G4MaterialCutsCouple.hh"
52 #include "G4ParticleTable.hh"
53
54 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
55
56 std::size_t G4EmSaturation::nMaterials = 0;
57 std::vector<G4double> G4EmSaturation::massFactors;
58 std::vector<G4double> G4EmSaturation::effCharges;
59 std::vector<G4double> G4EmSaturation::g4MatData;
60 std::vector<G4String> G4EmSaturation::g4MatNames;
61
62 G4EmSaturation::G4EmSaturation(G4int verb)
63 {
64 verbose = verb;
65 nWarnings = nG4Birks = 0;
66
67 electron = nullptr;
68 proton = nullptr;
69 nist = G4NistManager::Instance();
70 InitialiseG4Saturation();
71 }
72
73 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
74
75 G4EmSaturation::~G4EmSaturation() = default;
76
77 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
78
79 G4double G4EmSaturation::VisibleEnergyDeposition(
80 const G4ParticleDefinition* p,
81 const G4MaterialCutsCouple* couple,
82 G4double length,
83 G4double edep,
84 G4double niel) const
85 {
86 // no energy deposition
87 if(edep <= 0.0) { return 0.0; }
88
89 // zero step length may happens only if step limiter process
90 // is applied, in that case saturation should not be applied
91 if(length <= 0.0) { return edep; }
92
93 G4double evis = edep;
94 G4double bfactor = couple->GetMaterial()->GetIonisation()->GetBirksConstant();
95
96 if(bfactor > 0.0) {
97
98 // atomic relaxations for gamma incident
99 if(22 == p->GetPDGEncoding()) {
100 //G4cout << "%% gamma edep= " << edep/keV << " keV " << G4endl;
101 evis /= (1.0 + bfactor*edep/
102 G4LossTableManager::Instance()->GetRange(electron,edep,couple));
103
104 // energy loss
105 } else {
106
107 // protections
108 G4double nloss = std::max(niel, 0.0);
109 G4double eloss = edep - nloss;
110
111 // neutrons and neutral hadrons
112 if(0.0 == p->GetPDGCharge() || eloss < 0.0) {
113 nloss = edep;
114 eloss = 0.0;
115 } else {
116
117 // continues energy loss
118 eloss /= (1.0 + bfactor*eloss/length);
119 }
120 // non-ionizing energy loss
121 if(nloss > 0.0) {
122 std::size_t idx = couple->GetMaterial()->GetIndex();
123 G4double escaled = nloss*massFactors[idx];
124 /*
125 G4cout << "%% p edep= " << nloss/keV << " keV Escaled= "
126 << escaled << " MeV in " << couple->GetMaterial()->GetName()
127 << " " << p->GetParticleName()
128 << G4endl;
129 G4cout << proton->GetParticleName() << G4endl;
130 */
131 G4double range = G4LossTableManager::Instance()
132 ->GetRange(proton,escaled,couple)/effCharges[idx];
133 nloss /= (1.0 + bfactor*nloss/range);
134 }
135 evis = eloss + nloss;
136 }
137 }
138 return evis;
139 }
140
141 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
142
143 void G4EmSaturation::InitialiseG4Saturation()
144 {
145 if(nMaterials == G4Material::GetNumberOfMaterials()) { return; }
146 nMaterials = G4Material::GetNumberOfMaterials();
147 massFactors.resize(nMaterials, 1.0);
148 effCharges.resize(nMaterials, 1.0);
149
150 if(0 == nG4Birks) { InitialiseG4materials(); }
151
152 for(std::size_t i=0; i<nMaterials; ++i) {
153 InitialiseBirksCoefficient((*G4Material::GetMaterialTable())[i]);
154 }
155 if(verbose > 0) { DumpBirksCoefficients(); }
156 }
157
158 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
159
160 G4double G4EmSaturation::FindG4BirksCoefficient(const G4Material* mat)
161 {
162 if(0 == nG4Birks) { InitialiseG4materials(); }
163
164 G4String name = mat->GetName();
165 // is this material in the vector?
166
167 for(G4int j=0; j<nG4Birks; ++j) {
168 if(name == g4MatNames[j]) {
169 if(verbose > 0)
170 G4cout << "### G4EmSaturation::FindG4BirksCoefficient for "
171 << name << " is " << g4MatData[j]*MeV/mm << " mm/MeV "
172 << G4endl;
173 return g4MatData[j];
174 }
175 }
176 return 0.0;
177 }
178
179 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
180
181 void G4EmSaturation::InitialiseBirksCoefficient(const G4Material* mat)
182 {
183 // electron and proton should exist in any case
184 if(nullptr == electron) {
185 electron = G4ParticleTable::GetParticleTable()->FindParticle("e-");
186 proton = G4ParticleTable::GetParticleTable()->FindParticle("proton");
187 if(nullptr == electron) {
188 G4Exception("G4EmSaturation::InitialiseBirksCoefficient", "em0001",
189 FatalException, "electron should exist");
190 }
191 }
192
193 G4double curBirks = mat->GetIonisation()->GetBirksConstant();
194
195 G4String name = mat->GetName();
196
197 // material has no Birks coeffitient defined
198 // seach in the Geant4 list
199 if(curBirks == 0.0) {
200 for(G4int j=0; j<nG4Birks; ++j) {
201 if(name == g4MatNames[j]) {
202 mat->GetIonisation()->SetBirksConstant(g4MatData[j]);
203 curBirks = g4MatData[j];
204 break;
205 }
206 }
207 }
208
209 if(curBirks == 0.0) { return; }
210
211 // compute mean mass ratio
212 G4double curRatio = 0.0;
213 G4double curChargeSq = 0.0;
214 G4double norm = 0.0;
215 const G4ElementVector* theElementVector = mat->GetElementVector();
216 const G4double* theAtomNumDensityVector = mat->GetVecNbOfAtomsPerVolume();
217 std::size_t nelm = mat->GetNumberOfElements();
218 for (std::size_t i=0; i<nelm; ++i) {
219 const G4Element* elm = (*theElementVector)[i];
220 G4int Z = elm->GetZasInt();
221 G4double w = theAtomNumDensityVector[i];
222 curRatio += w/nist->GetAtomicMassAmu(Z);
223 curChargeSq += (Z*Z)*w;
224 norm += w;
225 }
226 if ( norm > 0.0) { norm = 1.0/norm; }
227 curRatio *= (CLHEP::proton_mass_c2*norm);
228 curChargeSq *= norm;
229
230 // store results
231 std::size_t idx = mat->GetIndex();
232 massFactors[idx] = curRatio;
233 effCharges[idx] = curChargeSq;
234 }
235
236 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
237
238 void G4EmSaturation::DumpBirksCoefficients()
239 {
240 G4cout << "### Birks coefficients used in run time" << G4endl;
241 const G4MaterialTable* mtable = G4Material::GetMaterialTable();
242 for(std::size_t i=0; i<nMaterials; ++i) {
243 const G4Material* mat = (*mtable)[i];
244 G4double br = mat->GetIonisation()->GetBirksConstant();
245 if(br > 0.0) {
246 G4cout << " " << mat->GetName() << " "
247 << br*MeV/mm << " mm/MeV" << " "
248 << br*mat->GetDensity()*MeV*cm2/g
249 << " g/cm^2/MeV massFactor= " << massFactors[i]
250 << " effCharge= " << effCharges[i] << G4endl;
251 }
252 }
253 }
254
255 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
256
257 void G4EmSaturation::DumpG4BirksCoefficients()
258 {
259 if(nG4Birks > 0) {
260 G4cout << "### Birks coefficients for Geant4 materials" << G4endl;
261 for(G4int i=0; i<nG4Birks; ++i) {
262 G4cout << " " << g4MatNames[i] << " "
263 << g4MatData[i]*MeV/mm << " mm/MeV" << G4endl;
264 }
265 }
266 }
267
268 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
269
270 void G4EmSaturation::InitialiseG4materials()
271 {
272 nG4Birks = 4;
273 g4MatData.reserve(nG4Birks);
274
275 // M.Hirschberg et al., IEEE Trans. Nuc. Sci. 39 (1992) 511
276 // SCSN-38 kB = 0.00842 g/cm^2/MeV; rho = 1.06 g/cm^3
277 g4MatNames.push_back("G4_POLYSTYRENE");
278 g4MatData.push_back(0.07943*mm/MeV);
279
280 // C.Fabjan (private communication)
281 // kB = 0.006 g/cm^2/MeV; rho = 7.13 g/cm^3
282 g4MatNames.push_back("G4_BGO");
283 g4MatData.push_back(0.008415*mm/MeV);
284
285 // A.Ribon analysis of publications
286 // Scallettar et al., Phys. Rev. A25 (1982) 2419.
287 // NIM A 523 (2004) 275.
288 // kB = 0.022 g/cm^2/MeV; rho = 1.396 g/cm^3;
289 // ATLAS Efield = 10 kV/cm provide the strongest effect
290 // kB = 0.1576*mm/MeV
291 // A. Kiryunin and P.Strizenec "Geant4 hadronic
292 // working group meeting " kB = 0.041/9.13 g/cm^2/MeV
293 g4MatNames.push_back("G4_lAr");
294 g4MatData.push_back(0.032*mm/MeV);
295
296 //G4_BARIUM_FLUORIDE
297 //G4_CESIUM_IODIDE
298 //G4_GEL_PHOTO_EMULSION
299 //G4_PHOTO_EMULSION
300 //G4_PLASTIC_SC_VINYLTOLUENE
301 //G4_SODIUM_IODIDE
302 //G4_STILBENE
303 //G4_lAr
304
305 //G4_PbWO4 - CMS value
306 g4MatNames.push_back("G4_PbWO4");
307 g4MatData.push_back(0.0333333*mm/MeV);
308
309 //G4_Lucite
310
311 }
312
313 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
314