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25 // 25 //
26 /// \file electromagnetic/TestEm7/src/G4Screen 26 /// \file electromagnetic/TestEm7/src/G4ScreenedNuclearRecoil.cc
27 /// \brief Implementation of the G4ScreenedNuc 27 /// \brief Implementation of the G4ScreenedNuclearRecoil class
28 // 28 //
>> 29 // $Id: G4ScreenedNuclearRecoil.cc 91266 2015-06-29 06:48:42Z gcosmo $
29 // 30 //
30 // 31 //
31 // Class Description 32 // Class Description
32 // Process for screened electromagnetic nuclea << 33 // Process for screened electromagnetic nuclear elastic scattering;
33 // Physics comes from: 34 // Physics comes from:
34 // Marcus H. Mendenhall and Robert A. Weller, << 35 // Marcus H. Mendenhall and Robert A. Weller,
35 // "Algorithms for the rapid computation o << 36 // "Algorithms for the rapid computation of classical cross
36 // sections for screened Coulomb collision 37 // sections for screened Coulomb collisions "
37 // Nuclear Instruments and Methods in Phy << 38 // Nuclear Instruments and Methods in Physics Research B58 (1991) 11-17
38 // The only input required is a screening func 39 // The only input required is a screening function phi(r/a) which is the ratio
39 // of the actual interatomic potential for two << 40 // of the actual interatomic potential for two atoms with atomic
40 // numbers Z1 and Z2, 41 // numbers Z1 and Z2,
41 // to the unscreened potential Z1*Z2*e^2/r whe << 42 // to the unscreened potential Z1*Z2*e^2/r where e^2 is elm_coupling in
42 // Geant4 units 43 // Geant4 units
43 // 44 //
44 // First version, April 2004, Marcus H. Menden 45 // First version, April 2004, Marcus H. Mendenhall, Vanderbilt University
45 // 46 //
46 // 5 May, 2004, Marcus Mendenhall 47 // 5 May, 2004, Marcus Mendenhall
47 // Added an option for enhancing hard collisio << 48 // Added an option for enhancing hard collisions statistically, to allow
48 // backscattering calculations to be carried o 49 // backscattering calculations to be carried out with much improved event rates,
49 // without distorting the multiple-scattering 50 // without distorting the multiple-scattering broadening too much.
50 // the method SetCrossSectionHardening(G4doubl << 51 // the method SetCrossSectionHardening(G4double fraction, G4double
51 // Hardeni 52 // HardeningFactor)
52 // sets what fraction of the events will be ra 53 // sets what fraction of the events will be randomly hardened,
53 // and the factor by which the impact area is 54 // and the factor by which the impact area is reduced for such selected events.
54 // 55 //
55 // 21 November, 2004, Marcus Mendenhall 56 // 21 November, 2004, Marcus Mendenhall
56 // added static_nucleus to IsApplicable 57 // added static_nucleus to IsApplicable
57 // << 58 //
58 // 7 December, 2004, Marcus Mendenhall 59 // 7 December, 2004, Marcus Mendenhall
59 // changed mean free path of stopping particle 60 // changed mean free path of stopping particle from 0.0 to 1.0*nanometer
60 // to avoid new verbose warning about 0 MFP in 61 // to avoid new verbose warning about 0 MFP in 4.6.2p02
61 // << 62 //
62 // 17 December, 2004, Marcus Mendenhall 63 // 17 December, 2004, Marcus Mendenhall
63 // added code to permit screening out overly c << 64 // added code to permit screening out overly close collisions which are
64 // expected to be hadronic, not Coulombic 65 // expected to be hadronic, not Coulombic
65 // 66 //
66 // 19 December, 2004, Marcus Mendenhall 67 // 19 December, 2004, Marcus Mendenhall
67 // massive rewrite to add modular physics stag 68 // massive rewrite to add modular physics stages and plug-in cross section table
68 // computation. This allows one to select (e. << 69 // computation. This allows one to select (e.g.) between the normal external
69 // python process and an embedded python inter << 70 // python process and an embedded python interpreter (which is much faster)
70 // for generating the tables. 71 // for generating the tables.
71 // It also allows one to switch between sub-sa << 72 // It also allows one to switch between sub-sampled scattering (event biasing)
72 // and normal scattering, and between non-rela << 73 // and normal scattering, and between non-relativistic kinematics and
73 // relativistic kinematic approximations, with << 74 // relativistic kinematic approximations, without having a class for every
74 // combination. Further, one can add extra sta << 75 // combination. Further, one can add extra stages to the scattering, which can
75 // implement various book-keeping processes. 76 // implement various book-keeping processes.
76 // << 77 //
77 // January 2007, Marcus Mendenhall 78 // January 2007, Marcus Mendenhall
78 // Reorganized heavily for inclusion in Geant4 << 79 // Reorganized heavily for inclusion in Geant4 Core. All modules merged into
79 // one source and header, all historic code re 80 // one source and header, all historic code removed.
80 // << 81 //
81 // Class Description - End 82 // Class Description - End
82 83
83 //....oooOO0OOooo........oooOO0OOooo........oo 84 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
84 85
85 #include "G4ScreenedNuclearRecoil.hh" << 86 #include <stdio.h>
86 87
87 #include "globals.hh" 88 #include "globals.hh"
88 89
89 #include <stdio.h> << 90 #include "G4ScreenedNuclearRecoil.hh"
90 91
91 const char* G4ScreenedCoulombCrossSectionInfo: << 92 const char* G4ScreenedCoulombCrossSectionInfo::CVSFileVers() { return
92 { << 93 "G4ScreenedNuclearRecoil.cc,v 1.57 2008/05/07 11:51:26 marcus Exp GEANT4 tag ";
93 return "G4ScreenedNuclearRecoil.cc,v 1.57 20 <<
94 } 94 }
95 95
96 #include "c2_factory.hh" << 96 #include "G4ParticleTypes.hh"
97 << 97 #include "G4ParticleTable.hh"
>> 98 #include "G4IonTable.hh"
>> 99 #include "G4VParticleChange.hh"
>> 100 #include "G4ParticleChangeForLoss.hh"
98 #include "G4DataVector.hh" 101 #include "G4DataVector.hh"
99 #include "G4DynamicParticle.hh" << 102 #include "G4Track.hh"
>> 103 #include "G4Step.hh"
>> 104
>> 105 #include "G4Material.hh"
100 #include "G4Element.hh" 106 #include "G4Element.hh"
101 #include "G4ElementVector.hh" <<
102 #include "G4EmProcessSubType.hh" <<
103 #include "G4IonTable.hh" <<
104 #include "G4Isotope.hh" 107 #include "G4Isotope.hh"
105 #include "G4IsotopeVector.hh" <<
106 #include "G4LindhardPartition.hh" <<
107 #include "G4Material.hh" <<
108 #include "G4MaterialCutsCouple.hh" 108 #include "G4MaterialCutsCouple.hh"
109 #include "G4ParticleChangeForLoss.hh" << 109 #include "G4ElementVector.hh"
>> 110 #include "G4IsotopeVector.hh"
>> 111
>> 112 #include "G4EmProcessSubType.hh"
>> 113
110 #include "G4ParticleDefinition.hh" 114 #include "G4ParticleDefinition.hh"
111 #include "G4ParticleTable.hh" << 115 #include "G4DynamicParticle.hh"
112 #include "G4ParticleTypes.hh" <<
113 #include "G4ProcessManager.hh" 116 #include "G4ProcessManager.hh"
114 #include "G4StableIsotopes.hh" 117 #include "G4StableIsotopes.hh"
115 #include "G4Step.hh" << 118 #include "G4LindhardPartition.hh"
116 #include "G4Track.hh" << 119
117 #include "G4VParticleChange.hh" <<
118 #include "Randomize.hh" 120 #include "Randomize.hh"
119 121
120 #include <iomanip> <<
121 #include <iostream> 122 #include <iostream>
122 static c2_factory<G4double> c2; // this makes << 123 #include <iomanip>
>> 124
>> 125 #include "c2_factory.hh"
>> 126 static c2_factory<G4double> c2; // this makes a lot of notation shorter
123 typedef c2_ptr<G4double> c2p; 127 typedef c2_ptr<G4double> c2p;
124 128
125 G4ScreenedCoulombCrossSection::~G4ScreenedCoul 129 G4ScreenedCoulombCrossSection::~G4ScreenedCoulombCrossSection()
126 { 130 {
127 screeningData.clear(); << 131 screeningData.clear();
128 MFPTables.clear(); << 132 MFPTables.clear();
129 } 133 }
130 134
131 const G4double G4ScreenedCoulombCrossSection:: << 135 const G4double G4ScreenedCoulombCrossSection::massmap[nMassMapElements+1]={
132 0, 1.007940, 4.002602, 6.941000 << 136 0, 1.007940, 4.002602, 6.941000, 9.012182, 10.811000, 12.010700,
133 15.999400, 18.998403, 20.179700, 22.98977 << 137 14.006700, 15.999400, 18.998403, 20.179700, 22.989770, 24.305000, 26.981538,
134 32.065000, 35.453000, 39.948000, 39.09830 << 138 28.085500,
135 51.996100, 54.938049, 55.845000, 58.93320 << 139 30.973761, 32.065000, 35.453000, 39.948000, 39.098300, 40.078000, 44.955910,
136 72.640000, 74.921600, 78.960000, 79.90400 << 140 47.867000,
137 91.224000, 92.906380, 95.940000, 98.00000 << 141 50.941500, 51.996100, 54.938049, 55.845000, 58.933200, 58.693400, 63.546000,
138 112.411000, 114.818000, 118.710000, 121.7600 << 142 65.409000,
139 137.327000, 138.905500, 140.116000, 140.9076 << 143 69.723000, 72.640000, 74.921600, 78.960000, 79.904000, 83.798000, 85.467800,
140 157.250000, 158.925340, 162.500000, 164.9303 << 144 87.620000,
141 178.490000, 180.947900, 183.840000, 186.2070 << 145 88.905850, 91.224000, 92.906380, 95.940000, 98.000000, 101.070000, 102.905500,
142 200.590000, 204.383300, 207.200000, 208.9803 << 146 106.420000,
143 226.000000, 227.000000, 232.038100, 231.0358 << 147 107.868200, 112.411000, 114.818000, 118.710000, 121.760000, 127.600000,
144 247.000000, 247.000000, 251.000000, 252.0000 << 148 126.904470, 131.293000,
145 261.000000, 262.000000, 266.000000, 264.0000 << 149 132.905450, 137.327000, 138.905500, 140.116000, 140.907650, 144.240000,
146 285.000000, 282.500000, 289.000000, 287.5000 << 150 145.000000, 150.360000,
147 << 151 151.964000, 157.250000, 158.925340, 162.500000, 164.930320, 167.259000,
148 G4ParticleDefinition* << 152 168.934210, 173.040000,
149 G4ScreenedCoulombCrossSection::SelectRandomUnw << 153 174.967000, 178.490000, 180.947900, 183.840000, 186.207000, 190.230000,
150 { << 154 192.217000, 195.078000,
151 // Select randomly an element within the mat << 155 196.966550, 200.590000, 204.383300, 207.200000, 208.980380, 209.000000,
152 // density only << 156 210.000000, 222.000000,
153 const G4Material* material = couple->GetMate << 157 223.000000, 226.000000, 227.000000, 232.038100, 231.035880, 238.028910,
154 G4int nMatElements = material->GetNumberOfEl << 158 237.000000, 244.000000,
155 const G4ElementVector* elementVector = mater << 159 243.000000, 247.000000, 247.000000, 251.000000, 252.000000, 257.000000,
156 const G4Element* element = 0; << 160 258.000000, 259.000000,
157 G4ParticleDefinition* target = 0; << 161 262.000000, 261.000000, 262.000000, 266.000000, 264.000000, 277.000000,
158 << 162 268.000000, 281.000000,
159 // Special case: the material consists of on << 163 272.000000, 285.000000, 282.500000, 289.000000, 287.500000, 292.000000};
160 if (nMatElements == 1) { << 164
161 element = (*elementVector)[0]; << 165 G4ParticleDefinition*
162 } << 166 G4ScreenedCoulombCrossSection::SelectRandomUnweightedTarget(
163 else { << 167 const G4MaterialCutsCouple* couple)
164 // Composite material << 168 {
165 G4double random = G4UniformRand() * materi << 169 // Select randomly an element within the material, according to number
166 G4double nsum = 0.0; << 170 // density only
167 const G4double* atomDensities = material-> << 171 const G4Material* material = couple->GetMaterial();
168 << 172 G4int nMatElements = material->GetNumberOfElements();
169 for (G4int k = 0; k < nMatElements; k++) { << 173 const G4ElementVector* elementVector = material->GetElementVector();
170 nsum += atomDensities[k]; << 174 const G4Element *element=0;
171 element = (*elementVector)[k]; << 175 G4ParticleDefinition*target=0;
172 if (nsum >= random) break; << 176
173 } << 177 // Special case: the material consists of one element
174 } << 178 if (nMatElements == 1)
175 << 179 {
176 G4int N = 0; << 180 element= (*elementVector)[0];
177 G4int Z = element->GetZasInt(); <<
178 <<
179 G4int nIsotopes = element->GetNumberOfIsotop <<
180 if (0 < nIsotopes) { <<
181 if (Z <= 92) { <<
182 // we have no detailed material isotopic <<
183 // so use G4StableIsotopes table up to Z <<
184 static G4StableIsotopes theIso; <<
185 // get a stable isotope table for defaul <<
186 nIsotopes = theIso.GetNumberOfIsotopes(Z <<
187 G4double random = 100.0 * G4UniformRand( <<
188 // values are expressed as percent, sum <<
189 G4int tablestart = theIso.GetFirstIsotop <<
190 G4double asum = 0.0; <<
191 for (G4int i = 0; i < nIsotopes; i++) { <<
192 asum += theIso.GetAbundance(i + tables <<
193 N = theIso.GetIsotopeNucleonCount(i + <<
194 if (asum >= random) break; <<
195 } <<
196 } 181 }
197 else { << 182 else
198 // too heavy for stable isotope table, j << 183 {
199 N = (G4int)std::floor(element->GetN() + << 184 // Composite material
200 } << 185 G4double random = G4UniformRand() * material->GetTotNbOfAtomsPerVolume();
201 } << 186 G4double nsum=0.0;
202 else { << 187 const G4double *atomDensities=material->GetVecNbOfAtomsPerVolume();
203 G4int i; << 188
204 const G4IsotopeVector* isoV = element->Get << 189 for (G4int k=0 ; k < nMatElements ; k++ )
205 G4double random = G4UniformRand(); << 190 {
206 G4double* abundance = element->GetRelative << 191 nsum+=atomDensities[k];
207 G4double asum = 0.0; << 192 element= (*elementVector)[k];
208 for (i = 0; i < nIsotopes; i++) { << 193 if (nsum >= random) break;
209 asum += abundance[i]; << 194 }
210 N = (*isoV)[i]->GetN(); <<
211 if (asum >= random) break; <<
212 } 195 }
213 } <<
214 196
215 // get the official definition of this nucle << 197 G4int N=0;
216 // value of A note that GetIon is very slow, << 198 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
217 // we have already found ourselves. << 199
218 ParticleCache::iterator p = targetMap.find(Z << 200 G4int nIsotopes=element->GetNumberOfIsotopes();
219 if (p != targetMap.end()) { << 201 if(!nIsotopes) {
220 target = (*p).second; << 202 if(Z<=92) {
221 } << 203 // we have no detailed material isotopic info available,
222 else { << 204 // so use G4StableIsotopes table up to Z=92
223 target = G4IonTable::GetIonTable()->GetIon << 205 static G4StableIsotopes theIso;
224 targetMap[Z * 1000 + N] = target; << 206 // get a stable isotope table for default results
225 } << 207 nIsotopes=theIso.GetNumberOfIsotopes(Z);
226 return target; << 208 G4double random = 100.0*G4UniformRand();
>> 209 // values are expressed as percent, sum is 100
>> 210 G4int tablestart=theIso.GetFirstIsotope(Z);
>> 211 G4double asum=0.0;
>> 212 for(G4int i=0; i<nIsotopes; i++) {
>> 213 asum+=theIso.GetAbundance(i+tablestart);
>> 214 N=theIso.GetIsotopeNucleonCount(i+tablestart);
>> 215 if(asum >= random) break;
>> 216 }
>> 217 } else {
>> 218 // too heavy for stable isotope table, just use mean mass
>> 219 N=(G4int)std::floor(element->GetN()+0.5);
>> 220 }
>> 221 } else {
>> 222 G4int i;
>> 223 const G4IsotopeVector *isoV=element->GetIsotopeVector();
>> 224 G4double random = G4UniformRand();
>> 225 G4double *abundance=element->GetRelativeAbundanceVector();
>> 226 G4double asum=0.0;
>> 227 for(i=0; i<nIsotopes; i++) {
>> 228 asum+=abundance[i];
>> 229 N=(*isoV)[i]->GetN();
>> 230 if(asum >= random) break;
>> 231 }
>> 232 }
>> 233
>> 234 // get the official definition of this nucleus, to get the correct
>> 235 // value of A note that GetIon is very slow, so we will cache ones
>> 236 // we have already found ourselves.
>> 237 ParticleCache::iterator p=targetMap.find(Z*1000+N);
>> 238 if (p != targetMap.end()) {
>> 239 target=(*p).second;
>> 240 } else{
>> 241 target=G4IonTable::GetIonTable()->GetIon(Z, N, 0.0);
>> 242 targetMap[Z*1000+N]=target;
>> 243 }
>> 244 return target;
227 } 245 }
228 246
229 void G4ScreenedCoulombCrossSection::BuildMFPTa 247 void G4ScreenedCoulombCrossSection::BuildMFPTables()
230 { 248 {
231 const G4int nmfpvals = 200; << 249 const G4int nmfpvals=200;
232 <<
233 std::vector<G4double> evals(nmfpvals), mfpva <<
234 250
235 // sum up inverse MFPs per element for each << 251 std::vector<G4double> evals(nmfpvals), mfpvals(nmfpvals);
236 const G4MaterialTable* materialTable = G4Mat <<
237 if (materialTable == 0) { <<
238 return; <<
239 } <<
240 // G4Exception("G4ScreenedCoulombCrossSectio <<
241 //- no MaterialTable found)"); <<
242 <<
243 G4int nMaterials = G4Material::GetNumberOfMa <<
244 252
245 for (G4int matidx = 0; matidx < nMaterials; << 253 // sum up inverse MFPs per element for each material
246 const G4Material* material = (*materialTab << 254 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
247 const G4ElementVector& elementVector = *(m << 255 if (materialTable == 0) { return; }
248 const G4int nMatElements = material->GetNu << 256 //G4Exception("G4ScreenedCoulombCrossSection::BuildMFPTables
249 << 257 //- no MaterialTable found)");
250 const G4Element* element = 0; << 258
251 const G4double* atomDensities = material-> << 259 G4int nMaterials = G4Material::GetNumberOfMaterials();
252 << 260
253 G4double emin = 0, emax = 0; << 261 for (G4int matidx=0; matidx < nMaterials; matidx++) {
254 // find innermost range of cross section f << 262
255 for (G4int kel = 0; kel < nMatElements; ke << 263 const G4Material* material= (*materialTable)[matidx];
256 element = elementVector[kel]; << 264 const G4ElementVector &elementVector =
257 G4int Z = (G4int)std::floor(element->Get << 265 *(material->GetElementVector());
258 const G4_c2_function& ifunc = sigmaMap[Z << 266 const G4int nMatElements = material->GetNumberOfElements();
259 if (!kel || ifunc.xmin() > emin) emin = << 267
260 if (!kel || ifunc.xmax() < emax) emax = << 268 const G4Element *element=0;
261 } << 269 const G4double *atomDensities=material->GetVecNbOfAtomsPerVolume();
262 << 270
263 G4double logint = std::log(emax / emin) / << 271 G4double emin=0, emax=0;
264 // logarithmic increment for tables << 272 // find innermost range of cross section functions
265 << 273 for (G4int kel=0 ; kel < nMatElements ; kel++ )
266 // compute energy scale for interpolator. << 274 {
267 // both ends to avoid range errors << 275 element=elementVector[kel];
268 for (G4int i = 1; i < nmfpvals - 1; i++) << 276 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
269 evals[i] = emin * std::exp(logint * i); << 277 const G4_c2_function &ifunc=sigmaMap[Z];
270 evals.front() = emin; << 278 if(!kel || ifunc.xmin() > emin) emin=ifunc.xmin();
271 evals.back() = emax; << 279 if(!kel || ifunc.xmax() < emax) emax=ifunc.xmax();
272 << 280 }
273 // zero out the inverse mfp sums to start << 281
274 for (G4int eidx = 0; eidx < nmfpvals; eidx << 282 G4double logint=std::log(emax/emin) / (nmfpvals-1) ;
275 mfpvals[eidx] = 0.0; << 283 // logarithmic increment for tables
276 << 284
277 // sum inverse mfp for each element in thi << 285 // compute energy scale for interpolator. Force exact values at
278 // energy << 286 // both ends to avoid range errors
279 for (G4int kel = 0; kel < nMatElements; ke << 287 for (G4int i=1; i<nmfpvals-1; i++) evals[i]=emin*std::exp(logint*i);
280 element = elementVector[kel]; << 288 evals.front()=emin;
281 G4int Z = (G4int)std::floor(element->Get << 289 evals.back()=emax;
282 const G4_c2_function& sigma = sigmaMap[Z << 290
283 G4double ndens = atomDensities[kel]; << 291 // zero out the inverse mfp sums to start
284 // compute atom fraction for this elemen << 292 for (G4int eidx=0; eidx < nmfpvals; eidx++) mfpvals[eidx] = 0.0;
285 << 293
286 for (G4int eidx = 0; eidx < nmfpvals; ei << 294 // sum inverse mfp for each element in this material and for each
287 mfpvals[eidx] += ndens * sigma(evals[e << 295 // energy
288 } << 296 for (G4int kel=0 ; kel < nMatElements ; kel++ )
289 } << 297 {
290 << 298 element=elementVector[kel];
291 // convert inverse mfp to regular mfp << 299 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
292 for (G4int eidx = 0; eidx < nmfpvals; eidx << 300 const G4_c2_function &sigma=sigmaMap[Z];
293 mfpvals[eidx] = 1.0 / mfpvals[eidx]; << 301 G4double ndens = atomDensities[kel];
294 } << 302 // compute atom fraction for this element in this material
295 // and make a new interpolating function o << 303
296 MFPTables[matidx] = c2.log_log_interpolati << 304 for (G4int eidx=0; eidx < nmfpvals; eidx++) {
297 } << 305 mfpvals[eidx] += ndens*sigma(evals[eidx]);
>> 306 }
>> 307 }
>> 308
>> 309 // convert inverse mfp to regular mfp
>> 310 for (G4int eidx=0; eidx < nmfpvals; eidx++) {
>> 311 mfpvals[eidx] = 1.0/mfpvals[eidx];
>> 312 }
>> 313 // and make a new interpolating function out of the sum
>> 314 MFPTables[matidx] = c2.log_log_interpolating_function().load(evals,
>> 315 mfpvals,true,0,true,0);
>> 316 }
298 } 317 }
299 318
300 G4ScreenedNuclearRecoil::G4ScreenedNuclearReco << 319 G4ScreenedNuclearRecoil::
301 << 320 G4ScreenedNuclearRecoil(const G4String& processName,
302 << 321 const G4String &ScreeningKey,
303 << 322 G4bool GenerateRecoils,
304 : G4VDiscreteProcess(processName, fElectroma << 323 G4double RecoilCutoff, G4double PhysicsCutoff) :
305 screeningKey(ScreeningKey), << 324 G4VDiscreteProcess(processName, fElectromagnetic),
306 generateRecoils(GenerateRecoils), << 325 screeningKey(ScreeningKey),
307 avoidReactions(1), << 326 generateRecoils(GenerateRecoils), avoidReactions(1),
308 recoilCutoff(RecoilCutoff), << 327 recoilCutoff(RecoilCutoff), physicsCutoff(PhysicsCutoff),
309 physicsCutoff(PhysicsCutoff), << 328 hardeningFraction(0.0), hardeningFactor(1.0),
310 hardeningFraction(0.0), << 329 externalCrossSectionConstructor(0),
311 hardeningFactor(1.0), << 330 NIELPartitionFunction(new G4LindhardRobinsonPartition)
312 externalCrossSectionConstructor(0), <<
313 NIELPartitionFunction(new G4LindhardRobins <<
314 { 331 {
315 // for now, point to class instance of this. << 332 // for now, point to class instance of this. Doing it by creating a new
316 // one fails 333 // one fails
317 // to correctly update NIEL 334 // to correctly update NIEL
318 // not even this is needed... done in G4VPro 335 // not even this is needed... done in G4VProcess().
319 // pParticleChange=&aParticleChange; << 336 // pParticleChange=&aParticleChange;
320 processMaxEnergy = 50000.0 * MeV; << 337 processMaxEnergy=50000.0*MeV;
321 highEnergyLimit = 100.0 * MeV; << 338 highEnergyLimit=100.0*MeV;
322 lowEnergyLimit = physicsCutoff; << 339 lowEnergyLimit=physicsCutoff;
323 registerDepositedEnergy = 1; // by default, << 340 registerDepositedEnergy=1; // by default, don't hide NIEL
324 MFPScale = 1.0; << 341 MFPScale=1.0;
325 // SetVerboseLevel(2); 342 // SetVerboseLevel(2);
326 AddStage(new G4ScreenedCoulombClassicalKinem 343 AddStage(new G4ScreenedCoulombClassicalKinematics);
327 AddStage(new G4SingleScatter); << 344 AddStage(new G4SingleScatter);
328 SetProcessSubType(fCoulombScattering); 345 SetProcessSubType(fCoulombScattering);
329 } 346 }
330 347
331 void G4ScreenedNuclearRecoil::ResetTables() 348 void G4ScreenedNuclearRecoil::ResetTables()
332 { 349 {
333 std::map<G4int, G4ScreenedCoulombCrossSectio << 350
334 for (; xt != crossSectionHandlers.end(); xt+ << 351 std::map<G4int, G4ScreenedCoulombCrossSection*>::iterator xt=
335 delete (*xt).second; << 352 crossSectionHandlers.begin();
336 } << 353 for(;xt != crossSectionHandlers.end(); xt++) {
337 crossSectionHandlers.clear(); << 354 delete (*xt).second;
>> 355 }
>> 356 crossSectionHandlers.clear();
338 } 357 }
339 358
340 void G4ScreenedNuclearRecoil::ClearStages() 359 void G4ScreenedNuclearRecoil::ClearStages()
341 { 360 {
342 // I don't think I like deleting the process << 361 // I don't think I like deleting the processes here... they are better
343 // abandoned 362 // abandoned
344 // if the creator doesn't get rid of them 363 // if the creator doesn't get rid of them
345 // std::vector<G4ScreenedCollisionStage *>:: 364 // std::vector<G4ScreenedCollisionStage *>::iterator stage=
346 // collisionStages.begin(); << 365 //collisionStages.begin();
347 // for(; stage != collisionStages.end(); sta << 366 //for(; stage != collisionStages.end(); stage++) delete (*stage);
348 367
349 collisionStages.clear(); << 368 collisionStages.clear();
350 } 369 }
351 370
352 void G4ScreenedNuclearRecoil::SetNIELPartition << 371 void G4ScreenedNuclearRecoil::SetNIELPartitionFunction(
>> 372 const G4VNIELPartition *part)
353 { 373 {
354 if (NIELPartitionFunction) delete NIELPartit << 374 if(NIELPartitionFunction) delete NIELPartitionFunction;
355 NIELPartitionFunction = part; << 375 NIELPartitionFunction=part;
356 } 376 }
357 377
358 void G4ScreenedNuclearRecoil::DepositEnergy(G4 << 378 void G4ScreenedNuclearRecoil::DepositEnergy(G4int z1, G4double a1,
359 G4 << 379 const G4Material *material, G4double energy)
360 { 380 {
361 if (!NIELPartitionFunction) { << 381 if(!NIELPartitionFunction) {
362 IonizingLoss += energy; << 382 IonizingLoss+=energy;
363 } << 383 } else {
364 else { << 384 G4double part=NIELPartitionFunction->PartitionNIEL(z1, a1,
365 G4double part = NIELPartitionFunction->Par << 385 material, energy);
366 IonizingLoss += energy * (1 - part); << 386 IonizingLoss+=energy*(1-part);
367 NIEL += energy * part; << 387 NIEL += energy*part;
368 } << 388 }
369 } 389 }
370 390
371 G4ScreenedNuclearRecoil::~G4ScreenedNuclearRec 391 G4ScreenedNuclearRecoil::~G4ScreenedNuclearRecoil()
372 { 392 {
373 ResetTables(); << 393 ResetTables();
374 } 394 }
375 395
376 // returns true if it appears the nuclei colli << 396 // returns true if it appears the nuclei collided, and we are interested
377 // in checking 397 // in checking
378 G4bool G4ScreenedNuclearRecoil::CheckNuclearCo << 398 G4bool G4ScreenedNuclearRecoil::CheckNuclearCollision(
379 { << 399 G4double A, G4double a1, G4double apsis) {
380 return avoidReactions << 400 return avoidReactions && (apsis < (1.1*(std::pow(A,1.0/3.0)+
381 && (apsis < (1.1 * (std::pow(A, 1.0 / << 401 std::pow(a1,1.0/3.0)) + 1.4)*fermi);
382 // nuclei are within 1.4 fm (reduced pion Co << 402 // nuclei are within 1.4 fm (reduced pion Compton wavelength) of each
383 // other at apsis, << 403 // other at apsis,
384 // this is hadronic, skip it 404 // this is hadronic, skip it
385 } 405 }
386 406
387 G4ScreenedCoulombCrossSection* G4ScreenedNucle << 407 G4ScreenedCoulombCrossSection
388 { << 408 *G4ScreenedNuclearRecoil::GetNewCrossSectionHandler(void) {
389 G4ScreenedCoulombCrossSection* xc; << 409 G4ScreenedCoulombCrossSection *xc;
390 if (!externalCrossSectionConstructor) << 410 if(!externalCrossSectionConstructor)
391 xc = new G4NativeScreenedCoulombCrossSecti << 411 xc=new G4NativeScreenedCoulombCrossSection;
392 else << 412 else xc=externalCrossSectionConstructor->create();
393 xc = externalCrossSectionConstructor->crea << 413 xc->SetVerbosity(verboseLevel);
394 xc->SetVerbosity(verboseLevel); << 414 return xc;
395 return xc; <<
396 } 415 }
397 416
398 G4double G4ScreenedNuclearRecoil::GetMeanFreeP << 417 G4double G4ScreenedNuclearRecoil::GetMeanFreePath(const G4Track& track,
>> 418 G4double,
399 419 G4ForceCondition* cond)
400 { 420 {
401 const G4DynamicParticle* incoming = track.Ge << 421 const G4DynamicParticle* incoming = track.GetDynamicParticle();
402 G4double energy = incoming->GetKineticEnergy << 422 G4double energy = incoming->GetKineticEnergy();
403 G4double a1 = incoming->GetDefinition()->Get << 423 G4double a1=incoming->GetDefinition()->GetPDGMass()/amu_c2;
404 << 424
405 G4double meanFreePath; << 425 G4double meanFreePath;
406 *cond = NotForced; << 426 *cond=NotForced;
407 << 427
408 if (energy < lowEnergyLimit || energy < reco << 428 if (energy < lowEnergyLimit || energy < recoilCutoff*a1) {
409 *cond = Forced; << 429 *cond=Forced;
410 return 1.0 * nm; << 430 return 1.0*nm;
411 /* catch and stop slow particles to collec << 431 /* catch and stop slow particles to collect their NIEL! */
412 } << 432 } else if (energy > processMaxEnergy*a1) {
413 else if (energy > processMaxEnergy * a1) { << 433 return DBL_MAX; // infinite mean free path
414 return DBL_MAX; // infinite mean free pat << 434 } else if (energy > highEnergyLimit*a1) energy=highEnergyLimit*a1;
415 } << 435 /* constant MFP at high energy */
416 else if (energy > highEnergyLimit * a1) << 436
417 energy = highEnergyLimit * a1; << 437 G4double fz1=incoming->GetDefinition()->GetPDGCharge();
418 /* constant MFP at high energy */ << 438 G4int z1=(G4int)(fz1/eplus + 0.5);
419 << 439
420 G4double fz1 = incoming->GetDefinition()->Ge << 440 std::map<G4int, G4ScreenedCoulombCrossSection*>::iterator xh=
421 G4int z1 = (G4int)(fz1 / eplus + 0.5); << 441 crossSectionHandlers.find(z1);
422 << 442 G4ScreenedCoulombCrossSection *xs;
423 std::map<G4int, G4ScreenedCoulombCrossSectio << 443
424 G4ScreenedCoulombCrossSection* xs; << 444 if (xh==crossSectionHandlers.end()) {
425 << 445 xs =crossSectionHandlers[z1]=GetNewCrossSectionHandler();
426 if (xh == crossSectionHandlers.end()) { << 446 xs->LoadData(screeningKey, z1, a1, physicsCutoff);
427 xs = crossSectionHandlers[z1] = GetNewCros << 447 xs->BuildMFPTables();
428 xs->LoadData(screeningKey, z1, a1, physics << 448 } else xs=(*xh).second;
429 xs->BuildMFPTables(); << 449
430 } << 450 const G4MaterialCutsCouple* materialCouple =
431 else << 451 track.GetMaterialCutsCouple();
432 xs = (*xh).second; << 452 size_t materialIndex = materialCouple->GetMaterial()->GetIndex();
433 << 453
434 const G4MaterialCutsCouple* materialCouple = << 454 const G4_c2_function &mfp=*(*xs)[materialIndex];
435 size_t materialIndex = materialCouple->GetMa << 455
436 << 456 // make absolutely certain we don't get an out-of-range energy
437 const G4_c2_function& mfp = *(*xs)[materialI << 457 meanFreePath = mfp(std::min(std::max(energy, mfp.xmin()), mfp.xmax()));
438 << 458
439 // make absolutely certain we don't get an o << 459 // G4cout << "MFP: " << meanFreePath << " index " << materialIndex
440 meanFreePath = mfp(std::min(std::max(energy, << 460 //<< " energy " << energy << " MFPScale " << MFPScale << G4endl;
441 << 461
442 // G4cout << "MFP: " << meanFreePath << " in << 462 return meanFreePath*MFPScale;
443 //<< " energy " << energy << " MFPScale " << << 463 }
>> 464
>> 465 G4VParticleChange* G4ScreenedNuclearRecoil::PostStepDoIt(
>> 466 const G4Track& aTrack, const G4Step& aStep)
>> 467 {
>> 468 validCollision=1;
>> 469 pParticleChange->Initialize(aTrack);
>> 470 NIEL=0.0; // default is no NIEL deposited
>> 471 IonizingLoss=0.0;
>> 472
>> 473 // do universal setup
>> 474
>> 475 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
>> 476 G4ParticleDefinition *baseParticle=aTrack.GetDefinition();
>> 477
>> 478 G4double fz1=baseParticle->GetPDGCharge()/eplus;
>> 479 G4int z1=(G4int)(fz1+0.5);
>> 480 G4double a1=baseParticle->GetPDGMass()/amu_c2;
>> 481 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
>> 482
>> 483 // Select randomly one element and (possibly) isotope in the
>> 484 // current material.
>> 485 const G4MaterialCutsCouple* couple = aTrack.GetMaterialCutsCouple();
>> 486
>> 487 const G4Material* mat = couple->GetMaterial();
>> 488
>> 489 G4double P=0.0; // the impact parameter of this collision
>> 490
>> 491 if(incidentEnergy < GetRecoilCutoff()*a1) {
>> 492 // check energy sanity on entry
>> 493 DepositEnergy(z1, baseParticle->GetPDGMass()/amu_c2, mat,
>> 494 incidentEnergy);
>> 495 GetParticleChange().ProposeEnergy(0.0);
>> 496 // stop the particle and bail out
>> 497 validCollision=0;
>> 498 } else {
>> 499
>> 500 G4double numberDensity=mat->GetTotNbOfAtomsPerVolume();
>> 501 G4double lattice=0.5/std::pow(numberDensity,1.0/3.0);
>> 502 // typical lattice half-spacing
>> 503 G4double length=GetCurrentInteractionLength();
>> 504 G4double sigopi=1.0/(pi*numberDensity*length);
>> 505 // this is sigma0/pi
>> 506
>> 507 // compute the impact parameter very early, so if is rejected
>> 508 // as too far away, little effort is wasted
>> 509 // this is the TRIM method for determining an impact parameter
>> 510 // based on the flight path
>> 511 // this gives a cumulative distribution of
>> 512 // N(P)= 1-exp(-pi P^2 n l)
>> 513 // which says the probability of NOT hitting a disk of area
>> 514 // sigma= pi P^2 =exp(-sigma N l)
>> 515 // which may be reasonable
>> 516 if(sigopi < lattice*lattice) {
>> 517 // normal long-flight approximation
>> 518 P = std::sqrt(-std::log(G4UniformRand()) *sigopi);
>> 519 } else {
>> 520 // short-flight limit
>> 521 P = std::sqrt(G4UniformRand())*lattice;
>> 522 }
>> 523
>> 524 G4double fraction=GetHardeningFraction();
>> 525 if(fraction && G4UniformRand() < fraction) {
>> 526 // pick out some events, and increase the central cross
>> 527 // section by reducing the impact parameter
>> 528 P /= std::sqrt(GetHardeningFactor());
>> 529 }
>> 530
>> 531
>> 532 // check if we are far enough away that the energy transfer
>> 533 // must be below cutoff,
>> 534 // and leave everything alone if so, saving a lot of time.
>> 535 if(P*P > sigopi) {
>> 536 if(GetVerboseLevel() > 1)
>> 537 printf("ScreenedNuclear impact reject: length=%.3f P=%.4f limit=%.4f\n",
>> 538 length/angstrom, P/angstrom,std::sqrt(sigopi)/angstrom);
>> 539 // no collision, don't follow up with anything
>> 540 validCollision=0;
>> 541 }
>> 542 }
>> 543
>> 544 // find out what we hit, and record it in our kinematics block.
>> 545 kinematics.targetMaterial=mat;
>> 546 kinematics.a1=a1;
>> 547
>> 548 if(validCollision) {
>> 549 G4ScreenedCoulombCrossSection *xsect=
>> 550 GetCrossSectionHandlers()[z1];
>> 551 G4ParticleDefinition *recoilIon=
>> 552 xsect->SelectRandomUnweightedTarget(couple);
>> 553 kinematics.crossSection=xsect;
>> 554 kinematics.recoilIon=recoilIon;
>> 555 kinematics.impactParameter=P;
>> 556 kinematics.a2=recoilIon->GetPDGMass()/amu_c2;
>> 557 } else {
>> 558 kinematics.recoilIon=0;
>> 559 kinematics.impactParameter=0;
>> 560 kinematics.a2=0;
>> 561 }
>> 562
>> 563 std::vector<G4ScreenedCollisionStage *>::iterator stage=
>> 564 collisionStages.begin();
>> 565
>> 566 for(; stage != collisionStages.end(); stage++)
>> 567 (*stage)->DoCollisionStep(this,aTrack, aStep);
>> 568
>> 569 if(registerDepositedEnergy) {
>> 570 pParticleChange->ProposeLocalEnergyDeposit(IonizingLoss+NIEL);
>> 571 pParticleChange->ProposeNonIonizingEnergyDeposit(NIEL);
>> 572 //MHM G4cout << "depositing energy, total = "
>> 573 //<< IonizingLoss+NIEL << " NIEL = " << NIEL << G4endl;
>> 574 }
444 575
445 return meanFreePath * MFPScale; << 576 return G4VDiscreteProcess::PostStepDoIt( aTrack, aStep );
446 } 577 }
447 578
448 G4VParticleChange* G4ScreenedNuclearRecoil::Po << 579 G4ScreenedCoulombClassicalKinematics::G4ScreenedCoulombClassicalKinematics() :
>> 580 // instantiate all the needed functions statically, so no allocation is
>> 581 // done at run time
>> 582 // we will be solving x^2 - x phi(x*au)/eps - beta^2 == 0.0
>> 583 // or, for easier scaling, x'^2 - x' au phi(x')/eps - beta^2 au^2
>> 584 // note that only the last of these gets deleted, since it owns the rest
>> 585 phifunc(c2.const_plugin_function()),
>> 586 xovereps(c2.linear(0., 0., 0.)),
>> 587 // will fill this in with the right slope at run time
>> 588 diff(c2.quadratic(0., 0., 0., 1.)-xovereps*phifunc)
449 { 589 {
450 validCollision = 1; <<
451 pParticleChange->Initialize(aTrack); <<
452 NIEL = 0.0; // default is no NIEL deposited <<
453 IonizingLoss = 0.0; <<
454 <<
455 // do universal setup <<
456 <<
457 const G4DynamicParticle* incidentParticle = <<
458 G4ParticleDefinition* baseParticle = aTrack. <<
459 <<
460 G4double fz1 = baseParticle->GetPDGCharge() <<
461 G4int z1 = (G4int)(fz1 + 0.5); <<
462 G4double a1 = baseParticle->GetPDGMass() / a <<
463 G4double incidentEnergy = incidentParticle-> <<
464 <<
465 // Select randomly one element and (possibly <<
466 // current material. <<
467 const G4MaterialCutsCouple* couple = aTrack. <<
468 <<
469 const G4Material* mat = couple->GetMaterial( <<
470 <<
471 G4double P = 0.0; // the impact parameter o <<
472 <<
473 if (incidentEnergy < GetRecoilCutoff() * a1) <<
474 // check energy sanity on entry <<
475 DepositEnergy(z1, baseParticle->GetPDGMass <<
476 GetParticleChange().ProposeEnergy(0.0); <<
477 // stop the particle and bail out <<
478 validCollision = 0; <<
479 } <<
480 else { <<
481 G4double numberDensity = mat->GetTotNbOfAt <<
482 G4double lattice = 0.5 / std::pow(numberDe <<
483 // typical lattice half-spacing <<
484 G4double length = GetCurrentInteractionLen <<
485 G4double sigopi = 1.0 / (pi * numberDensit <<
486 // this is sigma0/pi <<
487 <<
488 // compute the impact parameter very early <<
489 // as too far away, little effort is waste <<
490 // this is the TRIM method for determining <<
491 // based on the flight path <<
492 // this gives a cumulative distribution of <<
493 // N(P)= 1-exp(-pi P^2 n l) <<
494 // which says the probability of NOT hitti <<
495 // sigma= pi P^2 =exp(-sigma N l) <<
496 // which may be reasonable <<
497 if (sigopi < lattice * lattice) { <<
498 // normal long-flight approximation <<
499 P = std::sqrt(-std::log(G4UniformRand()) <<
500 } <<
501 else { <<
502 // short-flight limit <<
503 P = std::sqrt(G4UniformRand()) * lattice <<
504 } <<
505 <<
506 G4double fraction = GetHardeningFraction() <<
507 if (fraction && G4UniformRand() < fraction <<
508 // pick out some events, and increase th <<
509 // section by reducing the impact parame <<
510 P /= std::sqrt(GetHardeningFactor()); <<
511 } <<
512 <<
513 // check if we are far enough away that th <<
514 // must be below cutoff, <<
515 // and leave everything alone if so, savin <<
516 if (P * P > sigopi) { <<
517 if (GetVerboseLevel() > 1) <<
518 printf("ScreenedNuclear impact reject: <<
519 P / angstrom, std::sqrt(sigopi) <<
520 // no collision, don't follow up with an <<
521 validCollision = 0; <<
522 } <<
523 } <<
524 <<
525 // find out what we hit, and record it in ou <<
526 kinematics.targetMaterial = mat; <<
527 kinematics.a1 = a1; <<
528 <<
529 if (validCollision) { <<
530 G4ScreenedCoulombCrossSection* xsect = Get <<
531 G4ParticleDefinition* recoilIon = xsect->S <<
532 kinematics.crossSection = xsect; <<
533 kinematics.recoilIon = recoilIon; <<
534 kinematics.impactParameter = P; <<
535 kinematics.a2 = recoilIon->GetPDGMass() / <<
536 } <<
537 else { <<
538 kinematics.recoilIon = 0; <<
539 kinematics.impactParameter = 0; <<
540 kinematics.a2 = 0; <<
541 } <<
542 <<
543 std::vector<G4ScreenedCollisionStage*>::iter <<
544 <<
545 for (; stage != collisionStages.end(); stage <<
546 (*stage)->DoCollisionStep(this, aTrack, aS <<
547 <<
548 if (registerDepositedEnergy) { <<
549 pParticleChange->ProposeLocalEnergyDeposit <<
550 pParticleChange->ProposeNonIonizingEnergyD <<
551 // MHM G4cout << "depositing energy, total <<
552 //<< IonizingLoss+NIEL << " NIEL = " << NI <<
553 } <<
554 <<
555 return G4VDiscreteProcess::PostStepDoIt(aTra <<
556 } 590 }
557 591
558 G4ScreenedCoulombClassicalKinematics::G4Screen << 592 G4bool G4ScreenedCoulombClassicalKinematics::DoScreeningComputation(
559 : // instantiate all the needed functions s << 593 G4ScreenedNuclearRecoil *master,
560 // done at run time << 594 const G4ScreeningTables *screen, G4double eps, G4double beta)
561 // we will be solving x^2 - x phi(x*au)/e << 595 {
562 // or, for easier scaling, x'^2 - x' au p << 596 G4double au=screen->au;
563 // note that only the last of these gets << 597 G4CoulombKinematicsInfo &kin=master->GetKinematics();
564 phifunc(c2.const_plugin_function()), << 598 G4double A=kin.a2;
565 xovereps(c2.linear(0., 0., 0.)), << 599 G4double a1=kin.a1;
566 // will fill this in with the right slope << 600
567 diff(c2.quadratic(0., 0., 0., 1.) - xovere << 601 G4double xx0; // first estimate of closest approach
568 {} << 602 if(eps < 5.0) {
569 << 603 G4double y=std::log(eps);
570 G4bool G4ScreenedCoulombClassicalKinematics::D << 604 G4double mlrho4=((((3.517e-4*y+1.401e-2)*y+2.393e-1)*y+2.734)*y+2.220);
571 << 605 G4double rho4=std::exp(-mlrho4); // W&M eq. 18
572 << 606 G4double bb2=0.5*beta*beta;
573 { << 607 xx0=std::sqrt(bb2+std::sqrt(bb2*bb2+rho4)); // W&M eq. 17
574 G4double au = screen->au; << 608 } else {
575 G4CoulombKinematicsInfo& kin = master->GetKi << 609 G4double ee=1.0/(2.0*eps);
576 G4double A = kin.a2; << 610 xx0=ee+std::sqrt(ee*ee+beta*beta); // W&M eq. 15 (Rutherford value)
577 G4double a1 = kin.a1; << 611 if(master->CheckNuclearCollision(A, a1, xx0*au)) return 0;
578 <<
579 G4double xx0; // first estimate of closest <<
580 if (eps < 5.0) { <<
581 G4double y = std::log(eps); <<
582 G4double mlrho4 = ((((3.517e-4 * y + 1.401 <<
583 G4double rho4 = std::exp(-mlrho4); // W&M <<
584 G4double bb2 = 0.5 * beta * beta; <<
585 xx0 = std::sqrt(bb2 + std::sqrt(bb2 * bb2 <<
586 } <<
587 else { <<
588 G4double ee = 1.0 / (2.0 * eps); <<
589 xx0 = ee + std::sqrt(ee * ee + beta * beta <<
590 if (master->CheckNuclearCollision(A, a1, x <<
591 // nuclei too close 612 // nuclei too close
>> 613
592 } 614 }
593 << 615
594 // we will be solving x^2 - x phi(x*au)/eps 616 // we will be solving x^2 - x phi(x*au)/eps - beta^2 == 0.0
595 // or, for easier scaling, x'^2 - x' au phi( 617 // or, for easier scaling, x'^2 - x' au phi(x')/eps - beta^2 au^2
596 xovereps.reset(0., 0.0, au / eps); // slope << 618 xovereps.reset(0., 0.0, au/eps); // slope of x*au/eps term
597 phifunc.set_function(&(screen->EMphiData.get << 619 phifunc.set_function(&(screen->EMphiData.get()));
598 // install interpolating table 620 // install interpolating table
599 G4double xx1, phip, phip2; 621 G4double xx1, phip, phip2;
600 G4int root_error; << 622 G4int root_error;
601 xx1 = diff->find_root(phifunc.xmin(), std::m << 623 xx1=diff->find_root(phifunc.xmin(), std::min(10*xx0*au,phifunc.xmax()),
602 std::min(xx0 * au, phi << 624 std::min(xx0*au, phifunc.xmax()), beta*beta*au*au,
603 &phip, &phip2) << 625 &root_error, &phip, &phip2)/au;
604 / au; << 626
605 << 627 if(root_error) {
606 if (root_error) { << 628 G4cout << "Screened Coulomb Root Finder Error" << G4endl;
607 G4cout << "Screened Coulomb Root Finder Er << 629 G4cout << "au " << au << " A " << A << " a1 " << a1
608 G4cout << "au " << au << " A " << A << " a << 630 << " xx1 " << xx1 << " eps " << eps
609 << " beta " << beta << G4endl; << 631 << " beta " << beta << G4endl;
610 G4cout << " xmin " << phifunc.xmin() << " << 632 G4cout << " xmin " << phifunc.xmin() << " xmax "
611 G4cout << " f(xmin) " << phifunc(phifunc.x << 633 << std::min(10*xx0*au,phifunc.xmax()) ;
612 << phifunc(std::min(10 * xx0 * au, << 634 G4cout << " f(xmin) " << phifunc(phifunc.xmin())
613 G4cout << " xstart " << std::min(xx0 * au, << 635 << " f(xmax) "
614 << beta * beta * au * au; << 636 << phifunc(std::min(10*xx0*au,phifunc.xmax())) ;
615 G4cout << G4endl; << 637 G4cout << " xstart " << std::min(xx0*au, phifunc.xmax())
616 throw c2_exception("Failed root find"); << 638 << " target " << beta*beta*au*au ;
617 } << 639 G4cout << G4endl;
618 << 640 throw c2_exception("Failed root find");
619 // phiprime is scaled by one factor of au be << 641 }
620 // at (xx0*au), << 642
621 G4double phiprime = phip * au; << 643 // phiprime is scaled by one factor of au because phi is evaluated
622 << 644 // at (xx0*au),
623 // lambda0 is from W&M 19 << 645 G4double phiprime=phip*au;
624 G4double lambda0 = << 646
625 1.0 / std::sqrt(0.5 + beta * beta / (2.0 * << 647 //lambda0 is from W&M 19
626 << 648 G4double lambda0=1.0/std::sqrt(0.5+beta*beta/(2.0*xx1*xx1)
627 // compute the 6-term Lobatto integral alpha << 649 -phiprime/(2.0*eps));
628 // different coefficients) << 650
629 // this is probably completely un-needed but << 651 // compute the 6-term Lobatto integral alpha (per W&M 21, with
630 // quality results, << 652 // different coefficients)
631 G4double alpha = (1.0 + lambda0) / 30.0; << 653 // this is probably completely un-needed but gives the highest
632 G4double xvals[] = {0.98302349, 0.84652241, << 654 // quality results,
633 G4double weights[] = {0.03472124, 0.14769029 << 655 G4double alpha=(1.0+ lambda0)/30.0;
634 for (G4int k = 0; k < 4; k++) { << 656 G4double xvals[]={0.98302349, 0.84652241, 0.53235309, 0.18347974};
635 G4double x, ff; << 657 G4double weights[]={0.03472124, 0.14769029, 0.23485003, 0.18602489};
636 x = xx1 / xvals[k]; << 658 for(G4int k=0; k<4; k++) {
637 ff = 1.0 / std::sqrt(1.0 - phifunc(x * au) << 659 G4double x, ff;
638 alpha += weights[k] * ff; << 660 x=xx1/xvals[k];
639 } << 661 ff=1.0/std::sqrt(1.0-phifunc(x*au)/(x*eps)-beta*beta/(x*x));
640 << 662 alpha+=weights[k]*ff;
641 phifunc.unset_function(); << 663 }
642 // throws an exception if used without setti << 664
643 << 665 phifunc.unset_function();
644 G4double thetac1 = pi * beta * alpha / xx1; << 666 // throws an exception if used without setting again
645 // complement of CM scattering angle << 667
646 G4double sintheta = std::sin(thetac1); // n << 668 G4double thetac1=pi*beta*alpha/xx1;
647 G4double costheta = -std::cos(thetac1); // << 669 // complement of CM scattering angle
648 // G4double psi=std::atan2(sintheta, costhet << 670 G4double sintheta=std::sin(thetac1); //note sin(pi-theta)=sin(theta)
649 // lab scattering angle (M&T 3rd eq. 8.69) << 671 G4double costheta=-std::cos(thetac1); // note cos(pi-theta)=-cos(theta)
650 << 672 // G4double psi=std::atan2(sintheta, costheta+a1/A);
651 // numerics note: because we checked above << 673 // lab scattering angle (M&T 3rd eq. 8.69)
652 // of beta which give real recoils, << 674
653 // we don't have to look too closely for the << 675 // numerics note: because we checked above for reasonable values
654 // (which would cause sin(theta) << 676 // of beta which give real recoils,
655 // and 1-cos(theta) to both vanish and make << 677 // we don't have to look too closely for theta -> 0 here
656 G4double zeta = std::atan2(sintheta, 1 - cos << 678 // (which would cause sin(theta)
657 // lab recoil angle (M&T 3rd eq. 8.73) << 679 // and 1-cos(theta) to both vanish and make the atan2 ill behaved).
658 G4double coszeta = std::cos(zeta); << 680 G4double zeta=std::atan2(sintheta, 1-costheta);
659 G4double sinzeta = std::sin(zeta); << 681 // lab recoil angle (M&T 3rd eq. 8.73)
660 << 682 G4double coszeta=std::cos(zeta);
661 kin.sinTheta = sintheta; << 683 G4double sinzeta=std::sin(zeta);
662 kin.cosTheta = costheta; << 684
663 kin.sinZeta = sinzeta; << 685 kin.sinTheta=sintheta;
664 kin.cosZeta = coszeta; << 686 kin.cosTheta=costheta;
665 return 1; // all OK, collision is valid << 687 kin.sinZeta=sinzeta;
666 } << 688 kin.cosZeta=coszeta;
667 << 689 return 1; // all OK, collision is valid
668 void G4ScreenedCoulombClassicalKinematics::DoC << 690 }
669 << 691
670 { << 692 void G4ScreenedCoulombClassicalKinematics::DoCollisionStep(
671 if (!master->GetValidCollision()) return; << 693 G4ScreenedNuclearRecoil *master,
672 << 694 const G4Track& aTrack, const G4Step&) {
673 G4ParticleChange& aParticleChange = master-> << 695
674 G4CoulombKinematicsInfo& kin = master->GetKi << 696 if(!master->GetValidCollision()) return;
675 << 697
676 const G4DynamicParticle* incidentParticle = << 698 G4ParticleChange &aParticleChange=master->GetParticleChange();
677 G4ParticleDefinition* baseParticle = aTrack. << 699 G4CoulombKinematicsInfo &kin=master->GetKinematics();
678 << 700
679 G4double incidentEnergy = incidentParticle-> << 701 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
680 << 702 G4ParticleDefinition *baseParticle=aTrack.GetDefinition();
681 // this adjustment to a1 gives the right res << 703
682 // (constant gamma) << 704 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
683 // relativistic collisions. Hard collisions << 705
684 // Coulombic and hadronic terms interfere an << 706 // this adjustment to a1 gives the right results for soft
685 G4double gamma = (1.0 + incidentEnergy / bas << 707 // (constant gamma)
686 G4double a1 = kin.a1 * gamma; // relativist << 708 // relativistic collisions. Hard collisions are wrong anyway, since the
687 << 709 // Coulombic and hadronic terms interfere and cannot be added.
688 G4ParticleDefinition* recoilIon = kin.recoil << 710 G4double gamma=(1.0+incidentEnergy/baseParticle->GetPDGMass());
689 G4double A = recoilIon->GetPDGMass() / amu_c << 711 G4double a1=kin.a1*gamma; // relativistic gamma correction
690 G4int Z = (G4int)((recoilIon->GetPDGCharge() << 712
691 << 713 G4ParticleDefinition *recoilIon=kin.recoilIon;
692 G4double Ec = incidentEnergy * (A / (A + a1) << 714 G4double A=recoilIon->GetPDGMass()/amu_c2;
693 // energy in CM frame (non-relativistic!) << 715 G4int Z=(G4int)((recoilIon->GetPDGCharge()/eplus)+0.5);
694 const G4ScreeningTables* screen = kin.crossS << 716
695 G4double au = screen->au; // screening leng << 717 G4double Ec = incidentEnergy*(A/(A+a1));
696 << 718 // energy in CM frame (non-relativistic!)
697 G4double beta = kin.impactParameter / au; << 719 const G4ScreeningTables *screen=kin.crossSection->GetScreening(Z);
698 // dimensionless impact parameter << 720 G4double au=screen->au; // screening length
699 G4double eps = Ec / (screen->z1 * Z * elm_co << 721
700 // dimensionless energy << 722 G4double beta = kin.impactParameter/au;
701 << 723 // dimensionless impact parameter
702 G4bool ok = DoScreeningComputation(master, s << 724 G4double eps = Ec/(screen->z1*Z*elm_coupling/au);
703 if (!ok) { << 725 // dimensionless energy
704 master->SetValidCollision(0); // flag bad << 726
705 return; // just bail out without setting << 727 G4bool ok=DoScreeningComputation(master, screen, eps, beta);
706 } << 728 if(!ok) {
707 << 729 master->SetValidCollision(0); // flag bad collision
708 G4double eRecoil = << 730 return; // just bail out without setting valid flag
709 4 * incidentEnergy * a1 * A * kin.cosZeta << 731 }
710 kin.eRecoil = eRecoil; << 732
711 << 733 G4double eRecoil=4*incidentEnergy*a1*A*kin.cosZeta*kin.cosZeta
712 if (incidentEnergy - eRecoil < master->GetRe << 734 /((a1+A)*(a1+A));
713 aParticleChange.ProposeEnergy(0.0); << 735 kin.eRecoil=eRecoil;
714 master->DepositEnergy(int(screen->z1), a1, << 736
715 } << 737 if(incidentEnergy-eRecoil < master->GetRecoilCutoff()*a1) {
716 << 738 aParticleChange.ProposeEnergy(0.0);
717 if (master->GetEnableRecoils() && eRecoil > << 739 master->DepositEnergy(int(screen->z1), a1, kin.targetMaterial,
718 kin.recoilIon = recoilIon; << 740 incidentEnergy-eRecoil);
719 } << 741 }
720 else { << 742
721 kin.recoilIon = 0; // this flags no recoi << 743 if(master->GetEnableRecoils() &&
722 master->DepositEnergy(Z, A, kin.targetMate << 744 eRecoil > master->GetRecoilCutoff() * kin.a2) {
723 } << 745 kin.recoilIon=recoilIon;
724 } << 746 } else {
725 << 747 kin.recoilIon=0; // this flags no recoil to be generated
726 void G4SingleScatter::DoCollisionStep(G4Screen << 748 master->DepositEnergy(Z, A, kin.targetMaterial, eRecoil) ;
727 const G4 << 749 }
728 { << 750 }
729 if (!master->GetValidCollision()) return; << 751
730 << 752 void G4SingleScatter::DoCollisionStep(G4ScreenedNuclearRecoil *master,
731 G4CoulombKinematicsInfo& kin = master->GetKi << 753 const G4Track& aTrack, const G4Step&) {
732 G4ParticleChange& aParticleChange = master-> << 754
733 << 755 if(!master->GetValidCollision()) return;
734 const G4DynamicParticle* incidentParticle = << 756
735 G4double incidentEnergy = incidentParticle-> << 757 G4CoulombKinematicsInfo &kin=master->GetKinematics();
736 G4double eRecoil = kin.eRecoil; << 758 G4ParticleChange &aParticleChange=master->GetParticleChange();
737 << 759
738 G4double azimuth = G4UniformRand() * (2.0 * << 760 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
739 G4double sa = std::sin(azimuth); << 761 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
740 G4double ca = std::cos(azimuth); << 762 G4double eRecoil=kin.eRecoil;
741 << 763
742 G4ThreeVector recoilMomentumDirection(kin.si << 764 G4double azimuth=G4UniformRand()*(2.0*pi);
743 G4ParticleMomentum incidentDirection = incid << 765 G4double sa=std::sin(azimuth);
744 recoilMomentumDirection = recoilMomentumDire << 766 G4double ca=std::cos(azimuth);
745 G4ThreeVector recoilMomentum = << 767
746 recoilMomentumDirection * std::sqrt(2.0 * << 768 G4ThreeVector recoilMomentumDirection(kin.sinZeta*ca,
747 << 769 kin.sinZeta*sa, kin.cosZeta);
748 if (aParticleChange.GetEnergy() != 0.0) { << 770 G4ParticleMomentum incidentDirection =
749 // DoKinematics hasn't stopped it! << 771 incidentParticle->GetMomentumDirection();
750 G4ThreeVector beamMomentum = incidentParti << 772 recoilMomentumDirection=
751 aParticleChange.ProposeMomentumDirection(b << 773 recoilMomentumDirection.rotateUz(incidentDirection);
752 aParticleChange.ProposeEnergy(incidentEner << 774 G4ThreeVector recoilMomentum=
753 } << 775 recoilMomentumDirection*std::sqrt(2.0*eRecoil*kin.a2*amu_c2);
754 << 776
755 if (kin.recoilIon) { << 777 if(aParticleChange.GetEnergy() != 0.0) {
756 G4DynamicParticle* recoil = << 778 // DoKinematics hasn't stopped it!
757 new G4DynamicParticle(kin.recoilIon, rec << 779 G4ThreeVector beamMomentum=
758 << 780 incidentParticle->GetMomentum()-recoilMomentum;
759 aParticleChange.SetNumberOfSecondaries(1); << 781 aParticleChange.ProposeMomentumDirection(beamMomentum.unit()) ;
760 aParticleChange.AddSecondary(recoil); << 782 aParticleChange.ProposeEnergy(incidentEnergy-eRecoil);
761 } << 783 }
>> 784
>> 785 if(kin.recoilIon) {
>> 786 G4DynamicParticle* recoil =
>> 787 new G4DynamicParticle (kin.recoilIon,
>> 788 recoilMomentumDirection,eRecoil) ;
>> 789
>> 790 aParticleChange.SetNumberOfSecondaries(1);
>> 791 aParticleChange.AddSecondary(recoil);
>> 792 }
762 } 793 }
763 794
764 G4bool G4ScreenedNuclearRecoil::IsApplicable(c << 795 G4bool G4ScreenedNuclearRecoil::
>> 796 IsApplicable(const G4ParticleDefinition& aParticleType)
765 { 797 {
766 return aParticleType == *(G4Proton::Proton() << 798 return aParticleType == *(G4Proton::Proton()) ||
767 || aParticleType.GetParticleType() == << 799 aParticleType.GetParticleType() == "nucleus" ||
>> 800 aParticleType.GetParticleType() == "static_nucleus";
768 } 801 }
769 802
770 void G4ScreenedNuclearRecoil::BuildPhysicsTabl << 803 void
>> 804 G4ScreenedNuclearRecoil::
>> 805 BuildPhysicsTable(const G4ParticleDefinition& aParticleType)
771 { 806 {
772 G4String nam = aParticleType.GetParticleName 807 G4String nam = aParticleType.GetParticleName();
773 if (nam == "GenericIon" || nam == "proton" | << 808 if(nam == "GenericIon" || nam == "proton"
774 || nam == "alpha" || nam == "He3") << 809 || nam == "deuteron" || nam == "triton"
775 { << 810 || nam == "alpha" || nam == "He3") {
776 G4cout << G4endl << GetProcessName() << ": 811 G4cout << G4endl << GetProcessName() << ": for " << nam
777 << " SubType= " << GetProcessSub << 812 << " SubType= " << GetProcessSubType()
778 << " maxEnergy(MeV)= " << proces << 813 << " maxEnergy(MeV)= " << processMaxEnergy/MeV << G4endl;
779 } 814 }
780 } 815 }
781 816
782 void G4ScreenedNuclearRecoil::DumpPhysicsTable << 817 void
>> 818 G4ScreenedNuclearRecoil::
>> 819 DumpPhysicsTable(const G4ParticleDefinition&)
>> 820 {
>> 821 }
783 822
784 // This used to be the file mhmScreenedNuclear 823 // This used to be the file mhmScreenedNuclearRecoil_native.cc
785 // it has been included here to collect this f << 824 // it has been included here to collect this file into a smaller
786 // number of packages 825 // number of packages
787 826
788 #include "G4DataVector.hh" 827 #include "G4DataVector.hh"
>> 828 #include "G4Material.hh"
789 #include "G4Element.hh" 829 #include "G4Element.hh"
790 #include "G4ElementVector.hh" <<
791 #include "G4Isotope.hh" 830 #include "G4Isotope.hh"
792 #include "G4Material.hh" <<
793 #include "G4MaterialCutsCouple.hh" 831 #include "G4MaterialCutsCouple.hh"
794 << 832 #include "G4ElementVector.hh"
795 #include <vector> 833 #include <vector>
796 834
797 G4_c2_function& ZBLScreening(G4int z1, G4int z << 835 G4_c2_function &ZBLScreening(G4int z1, G4int z2, size_t npoints,
>> 836 G4double rMax, G4double *auval)
798 { 837 {
799 static const size_t ncoef = 4; << 838 static const size_t ncoef=4;
800 static G4double scales[ncoef] = {-3.2, -0.94 << 839 static G4double scales[ncoef]={-3.2, -0.9432, -0.4028, -0.2016};
801 static G4double coefs[ncoef] = {0.1818, 0.50 << 840 static G4double coefs[ncoef]={0.1818,0.5099,0.2802,0.0281};
802 << 841
803 G4double au = 0.8854 * angstrom * 0.529 / (s << 842 G4double au=
804 std::vector<G4double> r(npoints), phi(npoint << 843 0.8854*angstrom*0.529/(std::pow(z1, 0.23)+std::pow(z2,0.23));
805 << 844 std::vector<G4double> r(npoints), phi(npoints);
806 for (size_t i = 0; i < npoints; i++) { << 845
807 G4double rr = (float)i / (float)(npoints - << 846 for(size_t i=0; i<npoints; i++) {
808 r[i] = rr * rr * rMax; << 847 G4double rr=(float)i/(float)(npoints-1);
809 // use quadratic r scale to make sampling << 848 r[i]=rr*rr*rMax;
810 G4double sum = 0.0; << 849 // use quadratic r scale to make sampling fine near the center
811 for (size_t j = 0; j < ncoef; j++) << 850 G4double sum=0.0;
812 sum += coefs[j] * std::exp(scales[j] * r << 851 for(size_t j=0; j<ncoef; j++)
813 phi[i] = sum; << 852 sum+=coefs[j]*std::exp(scales[j]*r[i]/au);
814 } << 853 phi[i]=sum;
815 << 854 }
816 // compute the derivative at the origin for <<
817 G4double phiprime0 = 0.0; <<
818 for (size_t j = 0; j < ncoef; j++) <<
819 phiprime0 += scales[j] * coefs[j] * std::e <<
820 phiprime0 *= (1.0 / au); // put back in nat <<
821 <<
822 *auval = au; <<
823 return c2.lin_log_interpolating_function().l <<
824 } <<
825 <<
826 G4_c2_function& MoliereScreening(G4int z1, G4i <<
827 { <<
828 static const size_t ncoef = 3; <<
829 static G4double scales[ncoef] = {-6.0, -1.2, <<
830 static G4double coefs[ncoef] = {0.10, 0.55, <<
831 <<
832 G4double au = 0.8853 * 0.529 * angstrom / st <<
833 std::vector<G4double> r(npoints), phi(npoint <<
834 <<
835 for (size_t i = 0; i < npoints; i++) { <<
836 G4double rr = (float)i / (float)(npoints - <<
837 r[i] = rr * rr * rMax; <<
838 // use quadratic r scale to make sampling <<
839 G4double sum = 0.0; <<
840 for (size_t j = 0; j < ncoef; j++) <<
841 sum += coefs[j] * std::exp(scales[j] * r <<
842 phi[i] = sum; <<
843 } <<
844 <<
845 // compute the derivative at the origin for <<
846 G4double phiprime0 = 0.0; <<
847 for (size_t j = 0; j < ncoef; j++) <<
848 phiprime0 += scales[j] * coefs[j] * std::e <<
849 phiprime0 *= (1.0 / au); // put back in nat <<
850 <<
851 *auval = au; <<
852 return c2.lin_log_interpolating_function().l <<
853 } <<
854 <<
855 G4_c2_function& LJScreening(G4int z1, G4int z2 <<
856 { <<
857 // from Loftager, Besenbacher, Jensen & Sore <<
858 // PhysRev A20, 1443++, 1979 <<
859 G4double au = 0.8853 * 0.529 * angstrom / st <<
860 std::vector<G4double> r(npoints), phi(npoint <<
861 <<
862 for (size_t i = 0; i < npoints; i++) { <<
863 G4double rr = (float)i / (float)(npoints - <<
864 r[i] = rr * rr * rMax; <<
865 // use quadratic r scale to make sampling <<
866 <<
867 G4double y = std::sqrt(9.67 * r[i] / au); <<
868 G4double ysq = y * y; <<
869 G4double phipoly = 1 + y + 0.3344 * ysq + <<
870 phi[i] = phipoly * std::exp(-y); <<
871 // G4cout << r[i] << " " << phi[i] << G4en <<
872 } <<
873 <<
874 // compute the derivative at the origin for <<
875 G4double logphiprime0 = (9.67 / 2.0) * (2 * <<
876 // #avoid 0/0 on first element <<
877 logphiprime0 *= (1.0 / au); // #put back in <<
878 <<
879 *auval = au; <<
880 return c2.lin_log_interpolating_function().l <<
881 } <<
882 <<
883 G4_c2_function& LJZBLScreening(G4int z1, G4int <<
884 { <<
885 // hybrid of LJ and ZBL, uses LJ if x < 0.25 <<
886 /// connector in between. These numbers are <<
887 // is very near the point where the function <<
888 G4double auzbl, aulj; <<
889 <<
890 c2p zbl = ZBLScreening(z1, z2, npoints, rMax <<
891 c2p lj = LJScreening(z1, z2, npoints, rMax, <<
892 <<
893 G4double au = (auzbl + aulj) * 0.5; <<
894 lj->set_domain(lj->xmin(), 0.25 * au); <<
895 zbl->set_domain(1.5 * au, zbl->xmax()); <<
896 <<
897 c2p conn = c2.connector_function(lj->xmax(), <<
898 c2_piecewise_function_p<G4double>& pw = c2.p <<
899 c2p keepit(pw); <<
900 pw.append_function(lj); <<
901 pw.append_function(conn); <<
902 pw.append_function(zbl); <<
903 <<
904 *auval = au; <<
905 keepit.release_for_return(); <<
906 return pw; <<
907 } <<
908 855
909 G4NativeScreenedCoulombCrossSection::~G4Native << 856 // compute the derivative at the origin for the spline
>> 857 G4double phiprime0=0.0;
>> 858 for(size_t j=0; j<ncoef; j++)
>> 859 phiprime0+=scales[j]*coefs[j]*std::exp(scales[j]*r[0]/au);
>> 860 phiprime0*=(1.0/au); // put back in natural units;
>> 861
>> 862 *auval=au;
>> 863 return c2.lin_log_interpolating_function().load(r, phi, false,
>> 864 phiprime0,true,0);
>> 865 }
>> 866
>> 867 G4_c2_function &MoliereScreening(G4int z1, G4int z2, size_t npoints,
>> 868 G4double rMax, G4double *auval)
>> 869 {
>> 870 static const size_t ncoef=3;
>> 871 static G4double scales[ncoef]={-6.0, -1.2, -0.3};
>> 872 static G4double coefs[ncoef]={0.10, 0.55, 0.35};
>> 873
>> 874 G4double au=0.8853*0.529*angstrom/std::sqrt(std::pow(z1, 0.6667)
>> 875 +std::pow(z2,0.6667));
>> 876 std::vector<G4double> r(npoints), phi(npoints);
>> 877
>> 878 for(size_t i=0; i<npoints; i++) {
>> 879 G4double rr=(float)i/(float)(npoints-1);
>> 880 r[i]=rr*rr*rMax;
>> 881 // use quadratic r scale to make sampling fine near the center
>> 882 G4double sum=0.0;
>> 883 for(size_t j=0; j<ncoef; j++)
>> 884 sum+=coefs[j]*std::exp(scales[j]*r[i]/au);
>> 885 phi[i]=sum;
>> 886 }
>> 887
>> 888 // compute the derivative at the origin for the spline
>> 889 G4double phiprime0=0.0;
>> 890 for(size_t j=0; j<ncoef; j++)
>> 891 phiprime0+=scales[j]*coefs[j]*std::exp(scales[j]*r[0]/au);
>> 892 phiprime0*=(1.0/au); // put back in natural units;
>> 893
>> 894 *auval=au;
>> 895 return c2.lin_log_interpolating_function().load(r, phi, false,
>> 896 phiprime0,true,0);
>> 897 }
>> 898
>> 899 G4_c2_function &LJScreening(G4int z1, G4int z2, size_t npoints,
>> 900 G4double rMax, G4double *auval)
>> 901 {
>> 902 //from Loftager, Besenbacher, Jensen & Sorensen
>> 903 //PhysRev A20, 1443++, 1979
>> 904 G4double au=0.8853*0.529*angstrom/std::sqrt(std::pow(z1, 0.6667)
>> 905 +std::pow(z2,0.6667));
>> 906 std::vector<G4double> r(npoints), phi(npoints);
>> 907
>> 908 for(size_t i=0; i<npoints; i++) {
>> 909 G4double rr=(float)i/(float)(npoints-1);
>> 910 r[i]=rr*rr*rMax;
>> 911 // use quadratic r scale to make sampling fine near the center
>> 912
>> 913 G4double y=std::sqrt(9.67*r[i]/au);
>> 914 G4double ysq=y*y;
>> 915 G4double phipoly=1+y+0.3344*ysq+0.0485*y*ysq+0.002647*ysq*ysq;
>> 916 phi[i]=phipoly*std::exp(-y);
>> 917 // G4cout << r[i] << " " << phi[i] << G4endl;
>> 918 }
910 919
911 G4NativeScreenedCoulombCrossSection::G4NativeS << 920 // compute the derivative at the origin for the spline
912 { << 921 G4double logphiprime0=(9.67/2.0)*(2*0.3344-1.0);
913 AddScreeningFunction("zbl", ZBLScreening); << 922 // #avoid 0/0 on first element
914 AddScreeningFunction("lj", LJScreening); << 923 logphiprime0 *= (1.0/au); // #put back in natural units
915 AddScreeningFunction("mol", MoliereScreening << 924
916 AddScreeningFunction("ljzbl", LJZBLScreening << 925 *auval=au;
>> 926 return c2.lin_log_interpolating_function().load(r, phi, false,
>> 927 logphiprime0*phi[0],
>> 928 true,0);
>> 929 }
>> 930
>> 931 G4_c2_function &LJZBLScreening(G4int z1, G4int z2, size_t npoints,
>> 932 G4double rMax, G4double *auval)
>> 933 {
>> 934 // hybrid of LJ and ZBL, uses LJ if x < 0.25*auniv, ZBL if x > 1.5*auniv, and
>> 935 /// connector in between. These numbers are selected so the switchover
>> 936 // is very near the point where the functions naturally cross.
>> 937 G4double auzbl, aulj;
>> 938
>> 939 c2p zbl=ZBLScreening(z1, z2, npoints, rMax, &auzbl);
>> 940 c2p lj=LJScreening(z1, z2, npoints, rMax, &aulj);
>> 941
>> 942 G4double au=(auzbl+aulj)*0.5;
>> 943 lj->set_domain(lj->xmin(), 0.25*au);
>> 944 zbl->set_domain(1.5*au,zbl->xmax());
>> 945
>> 946 c2p conn=
>> 947 c2.connector_function(lj->xmax(), lj, zbl->xmin(), zbl, true,0);
>> 948 c2_piecewise_function_p<G4double> &pw=c2.piecewise_function();
>> 949 c2p keepit(pw);
>> 950 pw.append_function(lj);
>> 951 pw.append_function(conn);
>> 952 pw.append_function(zbl);
>> 953
>> 954 *auval=au;
>> 955 keepit.release_for_return();
>> 956 return pw;
>> 957 }
>> 958
>> 959 G4NativeScreenedCoulombCrossSection::~G4NativeScreenedCoulombCrossSection() {
>> 960 }
>> 961
>> 962 G4NativeScreenedCoulombCrossSection::G4NativeScreenedCoulombCrossSection() {
>> 963 AddScreeningFunction("zbl", ZBLScreening);
>> 964 AddScreeningFunction("lj", LJScreening);
>> 965 AddScreeningFunction("mol", MoliereScreening);
>> 966 AddScreeningFunction("ljzbl", LJZBLScreening);
917 } 967 }
918 968
919 std::vector<G4String> G4NativeScreenedCoulombC << 969 std::vector<G4String>
920 { << 970 G4NativeScreenedCoulombCrossSection::GetScreeningKeys() const {
921 std::vector<G4String> keys; 971 std::vector<G4String> keys;
922 // find the available screening keys 972 // find the available screening keys
923 std::map<std::string, ScreeningFunc>::const_ << 973 std::map<std::string, ScreeningFunc>::const_iterator sfunciter=phiMap.begin();
924 for (; sfunciter != phiMap.end(); sfunciter+ << 974 for(; sfunciter != phiMap.end(); sfunciter++)
925 keys.push_back((*sfunciter).first); 975 keys.push_back((*sfunciter).first);
926 return keys; 976 return keys;
927 } 977 }
928 978
929 static inline G4double cm_energy(G4double a1, << 979 static inline G4double cm_energy(G4double a1, G4double a2, G4double t0) {
930 { << 980 // "relativistically correct energy in CM frame"
931 // "relativistically correct energy in CM fr << 981 G4double m1=a1*amu_c2, mass2=a2*amu_c2;
932 G4double m1 = a1 * amu_c2, mass2 = a2 * amu_ << 982 G4double mc2=(m1+mass2);
933 G4double mc2 = (m1 + mass2); << 983 G4double f=2.0*mass2*t0/(mc2*mc2);
934 G4double f = 2.0 * mass2 * t0 / (mc2 * mc2); << 984 // old way: return (f < 1e-6) ? 0.5*mc2*f : mc2*(std::sqrt(1.0+f)-1.0);
935 // old way: return (f < 1e-6) ? 0.5*mc2*f : << 985 // formally equivalent to previous, but numerically stable for all
936 // formally equivalent to previous, but nume << 986 // f without conditional
937 // f without conditional << 987 // uses identity (sqrt(1+x) - 1)(sqrt(1+x) + 1) = x
938 // uses identity (sqrt(1+x) - 1)(sqrt(1+x) + << 988 return mc2*f/(std::sqrt(1.0+f)+1.0);
939 return mc2 * f / (std::sqrt(1.0 + f) + 1.0); << 989 }
940 } << 990
941 << 991 static inline G4double thetac(G4double m1, G4double mass2, G4double eratio) {
942 static inline G4double thetac(G4double m1, G4d << 992 G4double s2th2=eratio*( (m1+mass2)*(m1+mass2)/(4.0*m1*mass2) );
943 { << 993 G4double sth2=std::sqrt(s2th2);
944 G4double s2th2 = eratio * ((m1 + mass2) * (m << 994 return 2.0*std::asin(sth2);
945 G4double sth2 = std::sqrt(s2th2); <<
946 return 2.0 * std::asin(sth2); <<
947 } 995 }
948 996
949 void G4NativeScreenedCoulombCrossSection::Load << 997 void G4NativeScreenedCoulombCrossSection::LoadData(G4String screeningKey,
>> 998 G4int z1, G4double a1,
950 999 G4double recoilCutoff)
951 { << 1000 {
952 static const size_t sigLen = 200; << 1001 static const size_t sigLen=200;
953 // since sigma doesn't matter much, a very c << 1002 // since sigma doesn't matter much, a very coarse table will do
954 G4DataVector energies(sigLen); << 1003 G4DataVector energies(sigLen);
955 G4DataVector data(sigLen); << 1004 G4DataVector data(sigLen);
956 << 1005
957 a1 = standardmass(z1); << 1006 a1=standardmass(z1);
958 // use standardized values for mass for buil << 1007 // use standardized values for mass for building tables
959 << 1008
960 const G4MaterialTable* materialTable = G4Mat << 1009 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
961 G4int nMaterials = G4Material::GetNumberOfMa << 1010 if (materialTable == 0) { return; }
962 << 1011 //G4Exception("mhmNativeCrossSection::LoadData - no MaterialTable found)");
963 for (G4int im = 0; im < nMaterials; im++) { << 1012
964 const G4Material* material = (*materialTab << 1013 G4int nMaterials = G4Material::GetNumberOfMaterials();
965 const G4ElementVector* elementVector = mat << 1014
966 const G4int nMatElements = material->GetNu << 1015 for (G4int im=0; im<nMaterials; im++)
967 << 1016 {
968 for (G4int iEl = 0; iEl < nMatElements; iE << 1017 const G4Material* material= (*materialTable)[im];
969 const G4Element* element = (*elementVect << 1018 const G4ElementVector* elementVector = material->GetElementVector();
970 G4int Z = element->GetZasInt(); << 1019 const G4int nMatElements = material->GetNumberOfElements();
971 G4double a2 = element->GetA() * (mole / << 1020
972 << 1021 for (G4int iEl=0; iEl<nMatElements; iEl++)
973 if (sigmaMap.find(Z) != sigmaMap.end()) << 1022 {
974 // we've already got this element << 1023 G4Element* element = (*elementVector)[iEl];
975 << 1024 G4int Z = (G4int) element->GetZ();
976 // find the screening function generator << 1025 G4double a2=element->GetA()*(mole/gram);
977 std::map<std::string, ScreeningFunc>::it << 1026
978 if (sfunciter == phiMap.end()) { << 1027 if(sigmaMap.find(Z)!=sigmaMap.end()) continue;
979 G4ExceptionDescription ed; << 1028 // we've already got this element
980 ed << "No such screening key <" << scr << 1029
981 G4Exception("G4NativeScreenedCoulombCr << 1030 // find the screening function generator we need
982 } << 1031 std::map<std::string, ScreeningFunc>::iterator sfunciter=
983 ScreeningFunc sfunc = (*sfunciter).secon << 1032 phiMap.find(screeningKey);
984 << 1033 if(sfunciter==phiMap.end()) {
985 G4double au; << 1034 G4ExceptionDescription ed;
986 G4_c2_ptr screen = sfunc(z1, Z, 200, 50. << 1035 ed << "No such screening key <"
987 // generate the screening data << 1036 << screeningKey << ">";
988 G4ScreeningTables st; << 1037 G4Exception("G4NativeScreenedCoulombCrossSection::LoadData",
989 << 1038 "em0003",FatalException,ed);
990 st.EMphiData = screen; // save our phi << 1039 }
991 st.z1 = z1; << 1040 ScreeningFunc sfunc=(*sfunciter).second;
992 st.m1 = a1; << 1041
993 st.z2 = Z; << 1042 G4double au;
994 st.m2 = a2; << 1043 G4_c2_ptr screen=sfunc(z1, Z, 200, 50.0*angstrom, &au);
995 st.emin = recoilCutoff; << 1044 // generate the screening data
996 st.au = au; << 1045 G4ScreeningTables st;
997 << 1046
998 // now comes the hard part... build the << 1047 st.EMphiData=screen; //save our phi table
999 // tables from the phi table << 1048 st.z1=z1; st.m1=a1; st.z2=Z; st.m2=a2; st.emin=recoilCutoff;
1000 // based on (pi-thetac) = pi*beta*alpha << 1049 st.au=au;
1001 // alpha is very nearly unity, always << 1050
1002 // so just solve it wth alpha=1, which << 1051 // now comes the hard part... build the total cross section
1003 // much easier << 1052 // tables from the phi table
1004 // this function returns an approximati << 1053 // based on (pi-thetac) = pi*beta*alpha/x0, but noting that
1005 // (beta/x0)^2=phi(x0)/(eps*x0)-1 ~ ((p << 1054 // alpha is very nearly unity, always
1006 // Since we don't need exact sigma valu << 1055 // so just solve it wth alpha=1, which makes the solution
1007 // (within a factor of 2 almost always) << 1056 // much easier
1008 // this rearranges to phi(x0)/(x0*eps) << 1057 // this function returns an approximation to
1009 // 2*theta/pi - theta^2/pi^2 << 1058 // (beta/x0)^2=phi(x0)/(eps*x0)-1 ~ ((pi-thetac)/pi)^2
1010 << 1059 // Since we don't need exact sigma values, this is good enough
1011 c2_linear_p<G4double>& c2eps = c2.linea << 1060 // (within a factor of 2 almost always)
1012 // will store an appropriate eps inside << 1061 // this rearranges to phi(x0)/(x0*eps) =
1013 G4_c2_ptr phiau = screen(c2.linear(0.0, << 1062 // 2*theta/pi - theta^2/pi^2
1014 G4_c2_ptr x0func(phiau / c2eps); << 1063
1015 // this will be phi(x)/(x*eps) when c2e << 1064 c2_linear_p<G4double> &c2eps=c2.linear(0.0, 0.0, 1.0);
1016 x0func->set_domain(1e-6 * angstrom / au << 1065 // will store an appropriate eps inside this in loop
1017 // needed for inverse function << 1066 G4_c2_ptr phiau=screen(c2.linear(0.0, 0.0, au));
1018 // use the c2_inverse_function interfac << 1067 G4_c2_ptr x0func(phiau/c2eps);
1019 // it is more efficient for an ordered << 1068 // this will be phi(x)/(x*eps) when c2eps is correctly set
1020 // computation of values. << 1069 x0func->set_domain(1e-6*angstrom/au, 0.9999*screen->xmax()/au);
1021 G4_c2_ptr x0_solution(c2.inverse_functi << 1070 // needed for inverse function
1022 << 1071 // use the c2_inverse_function interface for the root finder...
1023 G4double m1c2 = a1 * amu_c2; << 1072 // it is more efficient for an ordered
1024 G4double escale = z1 * Z * elm_coupling << 1073 // computation of values.
1025 // energy at screening distance << 1074 G4_c2_ptr x0_solution(c2.inverse_function(x0func));
1026 G4double emax = m1c2; << 1075
1027 // model is doubtful in very relativist << 1076 G4double m1c2=a1*amu_c2;
1028 G4double eratkin = 0.9999 * (4 * a1 * a << 1077 G4double escale=z1*Z*elm_coupling/au;
1029 // #maximum kinematic ratio possible at << 1078 // energy at screening distance
1030 G4double cmfact0 = st.emin / cm_energy( << 1079 G4double emax=m1c2;
1031 G4double l1 = std::log(emax); << 1080 // model is doubtful in very relativistic range
1032 G4double l0 = std::log(st.emin * cmfact << 1081 G4double eratkin=0.9999*(4*a1*a2)/((a1+a2)*(a1+a2));
1033 << 1082 // #maximum kinematic ratio possible at 180 degrees
1034 if (verbosity >= 1) << 1083 G4double cmfact0=st.emin/cm_energy(a1, a2, st.emin);
1035 G4cout << "Native Screening: " << scr << 1084 G4double l1=std::log(emax);
1036 << a2 << " " << recoilCutoff < << 1085 G4double l0=std::log(st.emin*cmfact0/eratkin);
1037 << 1086
1038 for (size_t idx = 0; idx < sigLen; idx+ << 1087 if(verbosity >=1)
1039 G4double ee = std::exp(idx * ((l1 - l << 1088 G4cout << "Native Screening: " << screeningKey << " "
1040 G4double gamma = 1.0 + ee / m1c2; << 1089 << z1 << " " << a1 << " " <<
1041 G4double eratio = (cmfact0 * st.emin) << 1090 Z << " " << a2 << " " << recoilCutoff << G4endl;
1042 // factor by which ee needs to be red << 1091
1043 G4double theta = thetac(gamma * a1, a << 1092 for(size_t idx=0; idx<sigLen; idx++) {
1044 << 1093 G4double ee=std::exp(idx*((l1-l0)/sigLen)+l0);
1045 G4double eps = cm_energy(a1, a2, ee) << 1094 G4double gamma=1.0+ee/m1c2;
1046 // #make sure lab energy is converted << 1095 G4double eratio=(cmfact0*st.emin)/ee;
1047 // calculations << 1096 // factor by which ee needs to be reduced to get emin
1048 c2eps.reset(0.0, 0.0, eps); << 1097 G4double theta=thetac(gamma*a1, a2, eratio);
1049 // set correct slope in this function << 1098
1050 << 1099 G4double eps=cm_energy(a1, a2, ee)/escale;
1051 G4double q = theta / pi; << 1100 // #make sure lab energy is converted to CM for these
1052 // G4cout << ee << " " << m1c2 << " " << 1101 // calculations
1053 // << eps << " " << theta << " " << q << 1102 c2eps.reset(0.0, 0.0, eps);
1054 // old way using root finder << 1103 // set correct slope in this function
1055 // G4double x0= x0func->find_root(1e- << 1104
1056 // 0.9999*screen.xmax()/au, 1.0, 2*q- << 1105 G4double q=theta/pi;
1057 // new way using c2_inverse_function << 1106 // G4cout << ee << " " << m1c2 << " " << gamma << " "
1058 // useful information so should be a << 1107 // << eps << " " << theta << " " << q << G4endl;
1059 // since we are scanning this in stri << 1108 // old way using root finder
1060 G4double x0 = 0; << 1109 // G4double x0= x0func->find_root(1e-6*angstrom/au,
1061 try { << 1110 // 0.9999*screen.xmax()/au, 1.0, 2*q-q*q);
1062 x0 = x0_solution(2 * q - q * q); << 1111 // new way using c2_inverse_function which caches
1063 } << 1112 // useful information so should be a bit faster
1064 catch (c2_exception&) { << 1113 // since we are scanning this in strict order.
1065 G4Exception("G4ScreenedNuclearRecoi << 1114 G4double x0=0;
1066 "failure in inverse sol << 1115 try {
1067 } << 1116 x0=x0_solution(2*q-q*q);
1068 G4double betasquared = x0 * x0 - x0 * << 1117 } catch(c2_exception e) {
1069 G4double sigma = pi * betasquared * a << 1118 //G4Exception(G4String("G4ScreenedNuclearRecoil: failure
1070 energies[idx] = ee; << 1119 //in inverse solution to generate MFP Tables: ")+e.what());
1071 data[idx] = sigma; << 1120 }
1072 } << 1121 G4double betasquared=x0*x0 - x0*phiau(x0)/eps;
1073 screeningData[Z] = st; << 1122 G4double sigma=pi*betasquared*au*au;
1074 sigmaMap[Z] = c2.log_log_interpolating_ << 1123 energies[idx]=ee;
1075 } << 1124 data[idx]=sigma;
1076 } << 1125 }
>> 1126 screeningData[Z]=st;
>> 1127 sigmaMap[Z] =
>> 1128 c2.log_log_interpolating_function().load(energies, data,
>> 1129 true,0,true,0);
>> 1130 }
>> 1131 }
1077 } 1132 }
1078 1133