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25 // 25 //
26 /// \file electromagnetic/TestEm7/src/G4Screen <<
27 /// \brief Implementation of the G4ScreenedNuc <<
28 // 26 //
>> 27 // G4ScreenedNuclearRecoil.cc,v 1.57 2008/05/07 11:51:26 marcus Exp
>> 28 // GEANT4 tag
29 // 29 //
30 // 30 //
31 // Class Description 31 // Class Description
32 // Process for screened electromagnetic nuclea << 32 // Process for screened electromagnetic nuclear elastic scattering;
33 // Physics comes from: 33 // Physics comes from:
34 // Marcus H. Mendenhall and Robert A. Weller, << 34 // Marcus H. Mendenhall and Robert A. Weller,
35 // "Algorithms for the rapid computation o << 35 // "Algorithms for the rapid computation of classical cross
36 // sections for screened Coulomb collision 36 // sections for screened Coulomb collisions "
37 // Nuclear Instruments and Methods in Phy << 37 // Nuclear Instruments and Methods in Physics Research B58 (1991) 11-17
38 // The only input required is a screening func 38 // The only input required is a screening function phi(r/a) which is the ratio
39 // of the actual interatomic potential for two << 39 // of the actual interatomic potential for two atoms with atomic numbers Z1 and Z2,
40 // numbers Z1 and Z2, << 40 // to the unscreened potential Z1*Z2*e^2/r where e^2 is elm_coupling in Geant4 units
41 // to the unscreened potential Z1*Z2*e^2/r whe <<
42 // Geant4 units <<
43 // 41 //
44 // First version, April 2004, Marcus H. Menden 42 // First version, April 2004, Marcus H. Mendenhall, Vanderbilt University
45 // 43 //
46 // 5 May, 2004, Marcus Mendenhall 44 // 5 May, 2004, Marcus Mendenhall
47 // Added an option for enhancing hard collisio << 45 // Added an option for enhancing hard collisions statistically, to allow
48 // backscattering calculations to be carried o 46 // backscattering calculations to be carried out with much improved event rates,
49 // without distorting the multiple-scattering 47 // without distorting the multiple-scattering broadening too much.
50 // the method SetCrossSectionHardening(G4doubl << 48 // the method SetCrossSectionHardening(G4double fraction, G4double HardeningFactor)
51 // Hardeni <<
52 // sets what fraction of the events will be ra 49 // sets what fraction of the events will be randomly hardened,
53 // and the factor by which the impact area is 50 // and the factor by which the impact area is reduced for such selected events.
54 // 51 //
55 // 21 November, 2004, Marcus Mendenhall 52 // 21 November, 2004, Marcus Mendenhall
56 // added static_nucleus to IsApplicable 53 // added static_nucleus to IsApplicable
57 // << 54 //
58 // 7 December, 2004, Marcus Mendenhall 55 // 7 December, 2004, Marcus Mendenhall
59 // changed mean free path of stopping particle 56 // changed mean free path of stopping particle from 0.0 to 1.0*nanometer
60 // to avoid new verbose warning about 0 MFP in 57 // to avoid new verbose warning about 0 MFP in 4.6.2p02
61 // << 58 //
62 // 17 December, 2004, Marcus Mendenhall 59 // 17 December, 2004, Marcus Mendenhall
63 // added code to permit screening out overly c << 60 // added code to permit screening out overly close collisions which are
64 // expected to be hadronic, not Coulombic 61 // expected to be hadronic, not Coulombic
65 // 62 //
66 // 19 December, 2004, Marcus Mendenhall 63 // 19 December, 2004, Marcus Mendenhall
67 // massive rewrite to add modular physics stag 64 // massive rewrite to add modular physics stages and plug-in cross section table
68 // computation. This allows one to select (e. << 65 // computation. This allows one to select (e.g.) between the normal external python
69 // python process and an embedded python inter << 66 // process and an embedded python interpreter (which is much faster) for generating
70 // for generating the tables. << 67 // the tables.
71 // It also allows one to switch between sub-sa << 68 // It also allows one to switch between sub-sampled scattering (event biasing) and
72 // and normal scattering, and between non-rela << 69 // normal scattering, and between non-relativistic kinematics and relativistic
73 // relativistic kinematic approximations, with << 70 // kinematic approximations, without having a class for every combination. Further, one can
74 // combination. Further, one can add extra sta << 71 // add extra stages to the scattering, which can implement various book-keeping processes.
75 // implement various book-keeping processes. << 72 //
76 // <<
77 // January 2007, Marcus Mendenhall 73 // January 2007, Marcus Mendenhall
78 // Reorganized heavily for inclusion in Geant4 << 74 // Reorganized heavily for inclusion in Geant4 Core. All modules merged into
79 // one source and header, all historic code re 75 // one source and header, all historic code removed.
80 // << 76 //
81 // Class Description - End 77 // Class Description - End
82 78
83 //....oooOO0OOooo........oooOO0OOooo........oo <<
84 79
85 #include "G4ScreenedNuclearRecoil.hh" << 80 #include <stdio.h>
86 81
87 #include "globals.hh" 82 #include "globals.hh"
88 83
89 #include <stdio.h> << 84 #include "G4ScreenedNuclearRecoil.hh"
90 85
91 const char* G4ScreenedCoulombCrossSectionInfo: << 86 const char* G4ScreenedCoulombCrossSectionInfo::CVSFileVers() { return
92 { << 87 "G4ScreenedNuclearRecoil.cc,v 1.57 2008/05/07 11:51:26 marcus Exp GEANT4 tag ";
93 return "G4ScreenedNuclearRecoil.cc,v 1.57 20 <<
94 } 88 }
95 89
96 #include "c2_factory.hh" << 90 #include "G4ParticleTypes.hh"
97 << 91 #include "G4ParticleTable.hh"
>> 92 #include "G4VParticleChange.hh"
>> 93 #include "G4ParticleChangeForLoss.hh"
98 #include "G4DataVector.hh" 94 #include "G4DataVector.hh"
99 #include "G4DynamicParticle.hh" << 95 #include "G4Track.hh"
>> 96 #include "G4Step.hh"
>> 97
>> 98 #include "G4Material.hh"
100 #include "G4Element.hh" 99 #include "G4Element.hh"
101 #include "G4ElementVector.hh" <<
102 #include "G4EmProcessSubType.hh" <<
103 #include "G4IonTable.hh" <<
104 #include "G4Isotope.hh" 100 #include "G4Isotope.hh"
105 #include "G4IsotopeVector.hh" <<
106 #include "G4LindhardPartition.hh" <<
107 #include "G4Material.hh" <<
108 #include "G4MaterialCutsCouple.hh" 101 #include "G4MaterialCutsCouple.hh"
109 #include "G4ParticleChangeForLoss.hh" << 102 #include "G4ElementVector.hh"
>> 103 #include "G4IsotopeVector.hh"
>> 104
>> 105 #include "G4EmProcessSubType.hh"
>> 106
>> 107 #include "G4RangeTest.hh"
110 #include "G4ParticleDefinition.hh" 108 #include "G4ParticleDefinition.hh"
111 #include "G4ParticleTable.hh" << 109 #include "G4DynamicParticle.hh"
112 #include "G4ParticleTypes.hh" <<
113 #include "G4ProcessManager.hh" 110 #include "G4ProcessManager.hh"
114 #include "G4StableIsotopes.hh" 111 #include "G4StableIsotopes.hh"
115 #include "G4Step.hh" << 112 #include "G4LindhardPartition.hh"
116 #include "G4Track.hh" << 113
117 #include "G4VParticleChange.hh" <<
118 #include "Randomize.hh" 114 #include "Randomize.hh"
119 115
120 #include <iomanip> << 116 #include "CLHEP/Units/PhysicalConstants.h"
>> 117
121 #include <iostream> 118 #include <iostream>
122 static c2_factory<G4double> c2; // this makes << 119 #include <iomanip>
>> 120
>> 121 #include "c2_factory.hh"
>> 122 static c2_factory<G4double> c2; // this makes a lot of notation shorter
123 typedef c2_ptr<G4double> c2p; 123 typedef c2_ptr<G4double> c2p;
124 124
125 G4ScreenedCoulombCrossSection::~G4ScreenedCoul 125 G4ScreenedCoulombCrossSection::~G4ScreenedCoulombCrossSection()
126 { 126 {
127 screeningData.clear(); << 127 screeningData.clear();
128 MFPTables.clear(); << 128 MFPTables.clear();
129 } 129 }
130 130
131 const G4double G4ScreenedCoulombCrossSection:: << 131 const G4double G4ScreenedCoulombCrossSection::massmap[nMassMapElements+1]={
132 0, 1.007940, 4.002602, 6.941000 << 132 0, 1.007940, 4.002602, 6.941000, 9.012182, 10.811000, 12.010700,
133 15.999400, 18.998403, 20.179700, 22.98977 << 133 14.006700, 15.999400, 18.998403, 20.179700, 22.989770, 24.305000, 26.981538, 28.085500,
134 32.065000, 35.453000, 39.948000, 39.09830 << 134 30.973761, 32.065000, 35.453000, 39.948000, 39.098300, 40.078000, 44.955910, 47.867000,
135 51.996100, 54.938049, 55.845000, 58.93320 << 135 50.941500, 51.996100, 54.938049, 55.845000, 58.933200, 58.693400, 63.546000, 65.409000,
136 72.640000, 74.921600, 78.960000, 79.90400 << 136 69.723000, 72.640000, 74.921600, 78.960000, 79.904000, 83.798000, 85.467800, 87.620000,
137 91.224000, 92.906380, 95.940000, 98.00000 << 137 88.905850, 91.224000, 92.906380, 95.940000, 98.000000, 101.070000, 102.905500, 106.420000,
138 112.411000, 114.818000, 118.710000, 121.7600 << 138 107.868200, 112.411000, 114.818000, 118.710000, 121.760000, 127.600000, 126.904470, 131.293000,
139 137.327000, 138.905500, 140.116000, 140.9076 << 139 132.905450, 137.327000, 138.905500, 140.116000, 140.907650, 144.240000, 145.000000, 150.360000,
140 157.250000, 158.925340, 162.500000, 164.9303 << 140 151.964000, 157.250000, 158.925340, 162.500000, 164.930320, 167.259000, 168.934210, 173.040000,
141 178.490000, 180.947900, 183.840000, 186.2070 << 141 174.967000, 178.490000, 180.947900, 183.840000, 186.207000, 190.230000, 192.217000, 195.078000,
142 200.590000, 204.383300, 207.200000, 208.9803 << 142 196.966550, 200.590000, 204.383300, 207.200000, 208.980380, 209.000000, 210.000000, 222.000000,
143 226.000000, 227.000000, 232.038100, 231.0358 << 143 223.000000, 226.000000, 227.000000, 232.038100, 231.035880, 238.028910, 237.000000, 244.000000,
144 247.000000, 247.000000, 251.000000, 252.0000 << 144 243.000000, 247.000000, 247.000000, 251.000000, 252.000000, 257.000000, 258.000000, 259.000000,
145 261.000000, 262.000000, 266.000000, 264.0000 << 145 262.000000, 261.000000, 262.000000, 266.000000, 264.000000, 277.000000, 268.000000, 281.000000,
146 285.000000, 282.500000, 289.000000, 287.5000 << 146 272.000000, 285.000000, 282.500000, 289.000000, 287.500000, 292.000000};
147 << 147
148 G4ParticleDefinition* << 148 G4ParticleDefinition* G4ScreenedCoulombCrossSection::SelectRandomUnweightedTarget(const G4MaterialCutsCouple* couple)
149 G4ScreenedCoulombCrossSection::SelectRandomUnw << 149 {
150 { << 150 // Select randomly an element within the material, according to number density only
151 // Select randomly an element within the mat << 151 const G4Material* material = couple->GetMaterial();
152 // density only << 152 G4int nMatElements = material->GetNumberOfElements();
153 const G4Material* material = couple->GetMate << 153 const G4ElementVector* elementVector = material->GetElementVector();
154 G4int nMatElements = material->GetNumberOfEl << 154 const G4Element *element=0;
155 const G4ElementVector* elementVector = mater << 155 G4ParticleDefinition*target=0;
156 const G4Element* element = 0; << 156
157 G4ParticleDefinition* target = 0; << 157 // Special case: the material consists of one element
158 << 158 if (nMatElements == 1)
159 // Special case: the material consists of on << 159 {
160 if (nMatElements == 1) { << 160 element= (*elementVector)[0];
161 element = (*elementVector)[0]; << 161 }
162 } << 162 else
163 else { << 163 {
164 // Composite material << 164 // Composite material
165 G4double random = G4UniformRand() * materi << 165 G4double random = G4UniformRand() * material->GetTotNbOfAtomsPerVolume();
166 G4double nsum = 0.0; << 166 G4double nsum=0.0;
167 const G4double* atomDensities = material-> << 167 const G4double *atomDensities=material->GetVecNbOfAtomsPerVolume();
168 << 168
169 for (G4int k = 0; k < nMatElements; k++) { << 169 for (G4int k=0 ; k < nMatElements ; k++ )
170 nsum += atomDensities[k]; << 170 {
171 element = (*elementVector)[k]; << 171 nsum+=atomDensities[k];
172 if (nsum >= random) break; << 172 element= (*elementVector)[k];
173 } << 173 if (nsum >= random) break;
174 } << 174 }
175 <<
176 G4int N = 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 } <<
197 else { <<
198 // too heavy for stable isotope table, j <<
199 N = (G4int)std::floor(element->GetN() + <<
200 } <<
201 } <<
202 else { <<
203 G4int i; <<
204 const G4IsotopeVector* isoV = element->Get <<
205 G4double random = G4UniformRand(); <<
206 G4double* abundance = element->GetRelative <<
207 G4double asum = 0.0; <<
208 for (i = 0; i < nIsotopes; i++) { <<
209 asum += abundance[i]; <<
210 N = (*isoV)[i]->GetN(); <<
211 if (asum >= random) break; <<
212 } 175 }
213 } <<
214 176
215 // get the official definition of this nucle << 177 G4int N=0;
216 // value of A note that GetIon is very slow, << 178 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
217 // we have already found ourselves. << 179
218 ParticleCache::iterator p = targetMap.find(Z << 180 G4int nIsotopes=element->GetNumberOfIsotopes();
219 if (p != targetMap.end()) { << 181 if(!nIsotopes) {
220 target = (*p).second; << 182 if(Z<=92) {
221 } << 183 // we have no detailed material isotopic info available,
222 else { << 184 // so use G4StableIsotopes table up to Z=92
223 target = G4IonTable::GetIonTable()->GetIon << 185 static G4StableIsotopes theIso; // get a stable isotope table for default results
224 targetMap[Z * 1000 + N] = target; << 186 nIsotopes=theIso.GetNumberOfIsotopes(Z);
225 } << 187 G4double random = 100.0*G4UniformRand(); // values are expressed as percent, sum is 100
226 return target; << 188 G4int tablestart=theIso.GetFirstIsotope(Z);
>> 189 G4double asum=0.0;
>> 190 for(G4int i=0; i<nIsotopes; i++) {
>> 191 asum+=theIso.GetAbundance(i+tablestart);
>> 192 N=theIso.GetIsotopeNucleonCount(i+tablestart);
>> 193 if(asum >= random) break;
>> 194 }
>> 195 } else {
>> 196 // too heavy for stable isotope table, just use mean mass
>> 197 N=(G4int)std::floor(element->GetN()+0.5);
>> 198 }
>> 199 } else {
>> 200 G4int i;
>> 201 const G4IsotopeVector *isoV=element->GetIsotopeVector();
>> 202 G4double random = G4UniformRand();
>> 203 G4double *abundance=element->GetRelativeAbundanceVector();
>> 204 G4double asum=0.0;
>> 205 for(i=0; i<nIsotopes; i++) {
>> 206 asum+=abundance[i];
>> 207 N=(*isoV)[i]->GetN();
>> 208 if(asum >= random) break;
>> 209 }
>> 210 }
>> 211
>> 212 // get the official definition of this nucleus, to get the correct value of A
>> 213 // note that GetIon is very slow, so we will cache ones we have already found ourselves.
>> 214 ParticleCache::iterator p=targetMap.find(Z*1000+N);
>> 215 if (p != targetMap.end()) {
>> 216 target=(*p).second;
>> 217 } else{
>> 218 target=G4ParticleTable::GetParticleTable()->GetIon(Z, N, 0.0);
>> 219 targetMap[Z*1000+N]=target;
>> 220 }
>> 221 return target;
227 } 222 }
228 223
229 void G4ScreenedCoulombCrossSection::BuildMFPTa 224 void G4ScreenedCoulombCrossSection::BuildMFPTables()
230 { 225 {
231 const G4int nmfpvals = 200; << 226 const G4int nmfpvals=200;
232 <<
233 std::vector<G4double> evals(nmfpvals), mfpva <<
234 227
235 // sum up inverse MFPs per element for each << 228 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 <<
245 for (G4int matidx = 0; matidx < nMaterials; <<
246 const G4Material* material = (*materialTab <<
247 const G4ElementVector& elementVector = *(m <<
248 const G4int nMatElements = material->GetNu <<
249 <<
250 const G4Element* element = 0; <<
251 const G4double* atomDensities = material-> <<
252 <<
253 G4double emin = 0, emax = 0; <<
254 // find innermost range of cross section f <<
255 for (G4int kel = 0; kel < nMatElements; ke <<
256 element = elementVector[kel]; <<
257 G4int Z = (G4int)std::floor(element->Get <<
258 const G4_c2_function& ifunc = sigmaMap[Z <<
259 if (!kel || ifunc.xmin() > emin) emin = <<
260 if (!kel || ifunc.xmax() < emax) emax = <<
261 } <<
262 229
263 G4double logint = std::log(emax / emin) / << 230 // sum up inverse MFPs per element for each material
264 // logarithmic increment for tables << 231 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
265 << 232 if (materialTable == 0)
266 // compute energy scale for interpolator. << 233 G4Exception("G4ScreenedCoulombCrossSection::BuildMFPTables - no MaterialTable found)");
267 // both ends to avoid range errors << 234
268 for (G4int i = 1; i < nmfpvals - 1; i++) << 235 G4int nMaterials = G4Material::GetNumberOfMaterials();
269 evals[i] = emin * std::exp(logint * i); << 236
270 evals.front() = emin; << 237 for (G4int matidx=0; matidx < nMaterials; matidx++) {
271 evals.back() = emax; << 238
272 << 239 const G4Material* material= (*materialTable)[matidx];
273 // zero out the inverse mfp sums to start << 240 const G4ElementVector &elementVector = *(material->GetElementVector());
274 for (G4int eidx = 0; eidx < nmfpvals; eidx << 241 const G4int nMatElements = material->GetNumberOfElements();
275 mfpvals[eidx] = 0.0; << 242
276 << 243 const G4Element *element=0;
277 // sum inverse mfp for each element in thi << 244 const G4double *atomDensities=material->GetVecNbOfAtomsPerVolume();
278 // energy << 245
279 for (G4int kel = 0; kel < nMatElements; ke << 246 G4double emin=0, emax=0; // find innermost range of cross section functions
280 element = elementVector[kel]; << 247 for (G4int kel=0 ; kel < nMatElements ; kel++ )
281 G4int Z = (G4int)std::floor(element->Get << 248 {
282 const G4_c2_function& sigma = sigmaMap[Z << 249 element=elementVector[kel];
283 G4double ndens = atomDensities[kel]; << 250 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
284 // compute atom fraction for this elemen << 251 const G4_c2_function &ifunc=sigmaMap[Z];
285 << 252 if(!kel || ifunc.xmin() > emin) emin=ifunc.xmin();
286 for (G4int eidx = 0; eidx < nmfpvals; ei << 253 if(!kel || ifunc.xmax() < emax) emax=ifunc.xmax();
287 mfpvals[eidx] += ndens * sigma(evals[e << 254 }
288 } << 255
>> 256 G4double logint=std::log(emax/emin) / (nmfpvals-1) ; // logarithmic increment for tables
>> 257
>> 258 // compute energy scale for interpolator. Force exact values at both ends to avoid range errors
>> 259 for (G4int i=1; i<nmfpvals-1; i++) evals[i]=emin*std::exp(logint*i);
>> 260 evals.front()=emin;
>> 261 evals.back()=emax;
>> 262
>> 263 // zero out the inverse mfp sums to start
>> 264 for (G4int eidx=0; eidx < nmfpvals; eidx++) mfpvals[eidx] = 0.0;
>> 265
>> 266 // sum inverse mfp for each element in this material and for each energy
>> 267 for (G4int kel=0 ; kel < nMatElements ; kel++ )
>> 268 {
>> 269 element=elementVector[kel];
>> 270 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
>> 271 const G4_c2_function &sigma=sigmaMap[Z];
>> 272 G4double ndens = atomDensities[kel]; // compute atom fraction for this element in this material
>> 273
>> 274 for (G4int eidx=0; eidx < nmfpvals; eidx++) {
>> 275 mfpvals[eidx] += ndens*sigma(evals[eidx]);
>> 276 }
>> 277 }
>> 278
>> 279 // convert inverse mfp to regular mfp
>> 280 for (G4int eidx=0; eidx < nmfpvals; eidx++) {
>> 281 mfpvals[eidx] = 1.0/mfpvals[eidx];
>> 282 }
>> 283 // and make a new interpolating function out of the sum
>> 284 MFPTables[matidx] = c2.log_log_interpolating_function().load(evals, mfpvals,true,0,true,0);
289 } 285 }
>> 286 }
290 287
291 // convert inverse mfp to regular mfp << 288 G4ScreenedNuclearRecoil::
292 for (G4int eidx = 0; eidx < nmfpvals; eidx << 289 G4ScreenedNuclearRecoil(const G4String& processName,
293 mfpvals[eidx] = 1.0 / mfpvals[eidx]; << 290 const G4String &ScreeningKey,
294 } << 291 G4bool GenerateRecoils,
295 // and make a new interpolating function o << 292 G4double RecoilCutoff, G4double PhysicsCutoff) :
296 MFPTables[matidx] = c2.log_log_interpolati << 293 G4VDiscreteProcess(processName),
297 } << 294 screeningKey(ScreeningKey),
298 } << 295 generateRecoils(GenerateRecoils), avoidReactions(1),
299 << 296 recoilCutoff(RecoilCutoff), physicsCutoff(PhysicsCutoff),
300 G4ScreenedNuclearRecoil::G4ScreenedNuclearReco << 297 hardeningFraction(0.0), hardeningFactor(1.0),
301 << 298 externalCrossSectionConstructor(0),
302 << 299 NIELPartitionFunction(new G4LindhardRobinsonPartition)
303 << 300 {
304 : G4VDiscreteProcess(processName, fElectroma << 301 // for now, point to class instance of this. Doing it by creating a new one fails
305 screeningKey(ScreeningKey), << 302 // to correctly update NIEL
306 generateRecoils(GenerateRecoils), << 303 // not even this is needed... done in G4VProcess().
307 avoidReactions(1), << 304 // pParticleChange=&aParticleChange;
308 recoilCutoff(RecoilCutoff), << 305 processMaxEnergy=50000.0*MeV;
309 physicsCutoff(PhysicsCutoff), << 306 highEnergyLimit=100.0*MeV;
310 hardeningFraction(0.0), << 307 lowEnergyLimit=physicsCutoff;
311 hardeningFactor(1.0), << 308 registerDepositedEnergy=1; // by default, don't hide NIEL
312 externalCrossSectionConstructor(0), << 309 MFPScale=1.0;
313 NIELPartitionFunction(new G4LindhardRobins << 310 // SetVerboseLevel(2);
314 { << 311 AddStage(new G4ScreenedCoulombClassicalKinematics);
315 // for now, point to class instance of this. << 312 AddStage(new G4SingleScatter);
316 // one fails << 313 SetProcessSubType(fCoulombScattering);
317 // to correctly update NIEL <<
318 // not even this is needed... done in G4VPro <<
319 // pParticleChange=&aParticleChange; <<
320 processMaxEnergy = 50000.0 * MeV; <<
321 highEnergyLimit = 100.0 * MeV; <<
322 lowEnergyLimit = physicsCutoff; <<
323 registerDepositedEnergy = 1; // by default, <<
324 MFPScale = 1.0; <<
325 // SetVerboseLevel(2); <<
326 AddStage(new G4ScreenedCoulombClassicalKinem <<
327 AddStage(new G4SingleScatter); <<
328 SetProcessSubType(fCoulombScattering); <<
329 } 314 }
330 315
331 void G4ScreenedNuclearRecoil::ResetTables() 316 void G4ScreenedNuclearRecoil::ResetTables()
332 { 317 {
333 std::map<G4int, G4ScreenedCoulombCrossSectio << 318
334 for (; xt != crossSectionHandlers.end(); xt+ << 319 std::map<G4int, G4ScreenedCoulombCrossSection*>::iterator xt=crossSectionHandlers.begin();
335 delete (*xt).second; << 320 for(;xt != crossSectionHandlers.end(); xt++) {
336 } << 321 delete (*xt).second;
337 crossSectionHandlers.clear(); << 322 }
>> 323 crossSectionHandlers.clear();
338 } 324 }
339 325
340 void G4ScreenedNuclearRecoil::ClearStages() 326 void G4ScreenedNuclearRecoil::ClearStages()
341 { 327 {
342 // I don't think I like deleting the process << 328 // I don't think I like deleting the processes here... they are better abandoned
343 // abandoned << 329 // if the creator doesn't get rid of them
344 // if the creator doesn't get rid of them << 330 // std::vector<G4ScreenedCollisionStage *>::iterator stage=collisionStages.begin();
345 // std::vector<G4ScreenedCollisionStage *>:: << 331 //for(; stage != collisionStages.end(); stage++) delete (*stage);
346 // collisionStages.begin(); <<
347 // for(; stage != collisionStages.end(); sta <<
348 332
349 collisionStages.clear(); << 333 collisionStages.clear();
350 } 334 }
351 335
352 void G4ScreenedNuclearRecoil::SetNIELPartition << 336 void G4ScreenedNuclearRecoil::SetNIELPartitionFunction(const G4VNIELPartition *part)
353 { 337 {
354 if (NIELPartitionFunction) delete NIELPartit << 338 if(NIELPartitionFunction) delete NIELPartitionFunction;
355 NIELPartitionFunction = part; << 339 NIELPartitionFunction=part;
356 } 340 }
357 341
358 void G4ScreenedNuclearRecoil::DepositEnergy(G4 << 342 void G4ScreenedNuclearRecoil::DepositEnergy(G4int z1, G4double a1, const G4Material *material, G4double energy)
359 G4 <<
360 { 343 {
361 if (!NIELPartitionFunction) { << 344 if(!NIELPartitionFunction) {
362 IonizingLoss += energy; << 345 IonizingLoss+=energy;
363 } << 346 } else {
364 else { << 347 G4double part=NIELPartitionFunction->PartitionNIEL(z1, a1, material, energy);
365 G4double part = NIELPartitionFunction->Par << 348 IonizingLoss+=energy*(1-part);
366 IonizingLoss += energy * (1 - part); << 349 NIEL += energy*part;
367 NIEL += energy * part; << 350 }
368 } <<
369 } 351 }
370 352
371 G4ScreenedNuclearRecoil::~G4ScreenedNuclearRec 353 G4ScreenedNuclearRecoil::~G4ScreenedNuclearRecoil()
372 { 354 {
373 ResetTables(); << 355 ResetTables();
374 } 356 }
375 357
376 // returns true if it appears the nuclei colli << 358 // returns true if it appears the nuclei collided, and we are interested in checking
377 // in checking << 359 G4bool G4ScreenedNuclearRecoil::CheckNuclearCollision(
378 G4bool G4ScreenedNuclearRecoil::CheckNuclearCo << 360 G4double A, G4double a1, G4double apsis) {
379 { << 361 return avoidReactions && (apsis < (1.1*(std::pow(A,1.0/3.0)+std::pow(a1,1.0/3.0)) + 1.4)*fermi);
380 return avoidReactions << 362 // nuclei are within 1.4 fm (reduced pion Compton wavelength) of each other at apsis,
381 && (apsis < (1.1 * (std::pow(A, 1.0 / << 363 // this is hadronic, skip it
382 // nuclei are within 1.4 fm (reduced pion Co << 364 }
383 // other at apsis, << 365
384 // this is hadronic, skip it << 366 G4ScreenedCoulombCrossSection *G4ScreenedNuclearRecoil::GetNewCrossSectionHandler(void) {
385 } << 367 G4ScreenedCoulombCrossSection *xc;
386 << 368 if(!externalCrossSectionConstructor) xc=new G4NativeScreenedCoulombCrossSection;
387 G4ScreenedCoulombCrossSection* G4ScreenedNucle << 369 else xc=externalCrossSectionConstructor->create();
388 { << 370 xc->SetVerbosity(verboseLevel);
389 G4ScreenedCoulombCrossSection* xc; << 371 return xc;
390 if (!externalCrossSectionConstructor) << 372 }
391 xc = new G4NativeScreenedCoulombCrossSecti << 373
392 else << 374 G4double G4ScreenedNuclearRecoil::GetMeanFreePath(const G4Track& track,
393 xc = externalCrossSectionConstructor->crea << 375 G4double,
394 xc->SetVerbosity(verboseLevel); << 376 G4ForceCondition* cond)
395 return xc; << 377 {
396 } << 378 const G4DynamicParticle* incoming = track.GetDynamicParticle();
397 << 379 G4double energy = incoming->GetKineticEnergy();
398 G4double G4ScreenedNuclearRecoil::GetMeanFreeP << 380 G4double a1=incoming->GetDefinition()->GetPDGMass()/amu_c2;
399 << 381
400 { << 382 G4double meanFreePath;
401 const G4DynamicParticle* incoming = track.Ge << 383 *cond=NotForced;
402 G4double energy = incoming->GetKineticEnergy << 384
403 G4double a1 = incoming->GetDefinition()->Get << 385 if (energy < lowEnergyLimit || energy < recoilCutoff*a1) {
404 << 386 *cond=Forced;
405 G4double meanFreePath; << 387 return 1.0*nm; /* catch and stop slow particles to collect their NIEL! */
406 *cond = NotForced; << 388 } else if (energy > processMaxEnergy*a1) {
407 << 389 return DBL_MAX; // infinite mean free path
408 if (energy < lowEnergyLimit || energy < reco << 390 } else if (energy > highEnergyLimit*a1) energy=highEnergyLimit*a1; /* constant MFP at high energy */
409 *cond = Forced; << 391
410 return 1.0 * nm; << 392 G4double fz1=incoming->GetDefinition()->GetPDGCharge();
411 /* catch and stop slow particles to collec << 393 G4int z1=(G4int)(fz1/eplus + 0.5);
412 } << 394
413 else if (energy > processMaxEnergy * a1) { << 395 std::map<G4int, G4ScreenedCoulombCrossSection*>::iterator xh=
414 return DBL_MAX; // infinite mean free pat << 396 crossSectionHandlers.find(z1);
415 } << 397 G4ScreenedCoulombCrossSection *xs;
416 else if (energy > highEnergyLimit * a1) << 398
417 energy = highEnergyLimit * a1; << 399 if (xh==crossSectionHandlers.end()) {
418 /* constant MFP at high energy */ << 400 xs =crossSectionHandlers[z1]=GetNewCrossSectionHandler();
419 << 401 xs->LoadData(screeningKey, z1, a1, physicsCutoff);
420 G4double fz1 = incoming->GetDefinition()->Ge << 402 xs->BuildMFPTables();
421 G4int z1 = (G4int)(fz1 / eplus + 0.5); << 403 } else xs=(*xh).second;
422 << 404
423 std::map<G4int, G4ScreenedCoulombCrossSectio << 405 const G4MaterialCutsCouple* materialCouple = track.GetMaterialCutsCouple();
424 G4ScreenedCoulombCrossSection* xs; << 406 size_t materialIndex = materialCouple->GetMaterial()->GetIndex();
425 << 407
426 if (xh == crossSectionHandlers.end()) { << 408 const G4_c2_function &mfp=*(*xs)[materialIndex];
427 xs = crossSectionHandlers[z1] = GetNewCros << 409
428 xs->LoadData(screeningKey, z1, a1, physics << 410 // make absolutely certain we don't get an out-of-range energy
429 xs->BuildMFPTables(); << 411 meanFreePath = mfp(std::min(std::max(energy, mfp.xmin()), mfp.xmax()));
430 } << 412
431 else << 413 // G4cout << "MFP: " << meanFreePath << " index " << materialIndex << " energy " << energy << " MFPScale " << MFPScale << G4endl;
432 xs = (*xh).second; << 414
433 << 415 return meanFreePath*MFPScale;
434 const G4MaterialCutsCouple* materialCouple = <<
435 size_t materialIndex = materialCouple->GetMa <<
436 <<
437 const G4_c2_function& mfp = *(*xs)[materialI <<
438 <<
439 // make absolutely certain we don't get an o <<
440 meanFreePath = mfp(std::min(std::max(energy, <<
441 <<
442 // G4cout << "MFP: " << meanFreePath << " in <<
443 //<< " energy " << energy << " MFPScale " << <<
444 <<
445 return meanFreePath * MFPScale; <<
446 } 416 }
447 417
448 G4VParticleChange* G4ScreenedNuclearRecoil::Po 418 G4VParticleChange* G4ScreenedNuclearRecoil::PostStepDoIt(const G4Track& aTrack, const G4Step& aStep)
449 { 419 {
450 validCollision = 1; << 420 validCollision=1;
451 pParticleChange->Initialize(aTrack); << 421 pParticleChange->Initialize(aTrack);
452 NIEL = 0.0; // default is no NIEL deposited << 422 NIEL=0.0; // default is no NIEL deposited
453 IonizingLoss = 0.0; << 423 IonizingLoss=0.0;
454 << 424
455 // do universal setup << 425 // do universal setup
456 << 426
457 const G4DynamicParticle* incidentParticle = << 427 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
458 G4ParticleDefinition* baseParticle = aTrack. << 428 G4ParticleDefinition *baseParticle=aTrack.GetDefinition();
459 << 429
460 G4double fz1 = baseParticle->GetPDGCharge() << 430 G4double fz1=baseParticle->GetPDGCharge()/eplus;
461 G4int z1 = (G4int)(fz1 + 0.5); << 431 G4int z1=(G4int)(fz1+0.5);
462 G4double a1 = baseParticle->GetPDGMass() / a << 432 G4double a1=baseParticle->GetPDGMass()/amu_c2;
463 G4double incidentEnergy = incidentParticle-> << 433 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
464 << 434
465 // Select randomly one element and (possibly << 435 // Select randomly one element and (possibly) isotope in the current material.
466 // current material. << 436 const G4MaterialCutsCouple* couple = aTrack.GetMaterialCutsCouple();
467 const G4MaterialCutsCouple* couple = aTrack. << 437
468 << 438 const G4Material* mat = couple->GetMaterial();
469 const G4Material* mat = couple->GetMaterial( << 439
470 << 440 G4double P=0.0; // the impact parameter of this collision
471 G4double P = 0.0; // the impact parameter o << 441
472 << 442 if(incidentEnergy < GetRecoilCutoff()*a1) { // check energy sanity on entry
473 if (incidentEnergy < GetRecoilCutoff() * a1) << 443 DepositEnergy(z1, baseParticle->GetPDGMass()/amu_c2, mat, incidentEnergy);
474 // check energy sanity on entry << 444 GetParticleChange().ProposeEnergy(0.0);
475 DepositEnergy(z1, baseParticle->GetPDGMass << 445 // stop the particle and bail out
476 GetParticleChange().ProposeEnergy(0.0); << 446 validCollision=0;
477 // stop the particle and bail out << 447 } else {
478 validCollision = 0; << 448
479 } << 449 G4double numberDensity=mat->GetTotNbOfAtomsPerVolume();
480 else { << 450 G4double lattice=0.5/std::pow(numberDensity,1.0/3.0); // typical lattice half-spacing
481 G4double numberDensity = mat->GetTotNbOfAt << 451 G4double length=GetCurrentInteractionLength();
482 G4double lattice = 0.5 / std::pow(numberDe << 452 G4double sigopi=1.0/(CLHEP::pi*numberDensity*length); // this is sigma0/pi
483 // typical lattice half-spacing << 453
484 G4double length = GetCurrentInteractionLen << 454 // compute the impact parameter very early, so if is rejected as too far away, little effort is wasted
485 G4double sigopi = 1.0 / (pi * numberDensit << 455 // this is the TRIM method for determining an impact parameter based on the flight path
486 // this is sigma0/pi << 456 // this gives a cumulative distribution of N(P)= 1-exp(-pi P^2 n l)
487 << 457 // which says the probability of NOT hitting a disk of area sigma= pi P^2 =exp(-sigma N l)
488 // compute the impact parameter very early << 458 // which may be reasonable
489 // as too far away, little effort is waste << 459 if(sigopi < lattice*lattice) {
490 // this is the TRIM method for determining << 460 // normal long-flight approximation
491 // based on the flight path << 461 P = std::sqrt(-std::log(G4UniformRand()) *sigopi);
492 // this gives a cumulative distribution of << 462 } else {
493 // N(P)= 1-exp(-pi P^2 n l) << 463 // short-flight limit
494 // which says the probability of NOT hitti << 464 P = std::sqrt(G4UniformRand())*lattice;
495 // sigma= pi P^2 =exp(-sigma N l) << 465 }
496 // which may be reasonable << 466
497 if (sigopi < lattice * lattice) { << 467 G4double fraction=GetHardeningFraction();
498 // normal long-flight approximation << 468 if(fraction && G4UniformRand() < fraction) {
499 P = std::sqrt(-std::log(G4UniformRand()) << 469 // pick out some events, and increase the central cross section
500 } << 470 // by reducing the impact parameter
501 else { << 471 P /= std::sqrt(GetHardeningFactor());
502 // short-flight limit << 472 }
503 P = std::sqrt(G4UniformRand()) * lattice << 473
504 } << 474
505 << 475 // check if we are far enough away that the energy transfer must be below cutoff,
506 G4double fraction = GetHardeningFraction() << 476 // and leave everything alone if so, saving a lot of time.
507 if (fraction && G4UniformRand() < fraction << 477 if(P*P > sigopi) {
508 // pick out some events, and increase th << 478 if(GetVerboseLevel() > 1)
509 // section by reducing the impact parame << 479 printf("ScreenedNuclear impact reject: length=%.3f P=%.4f limit=%.4f\n",
510 P /= std::sqrt(GetHardeningFactor()); << 480 length/angstrom, P/angstrom,std::sqrt(sigopi)/angstrom);
511 } << 481 // no collision, don't follow up with anything
512 << 482 validCollision=0;
513 // check if we are far enough away that th << 483 }
514 // must be below cutoff, << 484 }
515 // and leave everything alone if so, savin << 485
516 if (P * P > sigopi) { << 486 // find out what we hit, and record it in our kinematics block.
517 if (GetVerboseLevel() > 1) << 487 kinematics.targetMaterial=mat;
518 printf("ScreenedNuclear impact reject: << 488 kinematics.a1=a1;
519 P / angstrom, std::sqrt(sigopi) << 489
520 // no collision, don't follow up with an << 490 if(validCollision) {
521 validCollision = 0; << 491 G4ScreenedCoulombCrossSection *xsect=GetCrossSectionHandlers()[z1];
522 } << 492 G4ParticleDefinition *recoilIon=
523 } << 493 xsect->SelectRandomUnweightedTarget(couple);
524 << 494 kinematics.crossSection=xsect;
525 // find out what we hit, and record it in ou << 495 kinematics.recoilIon=recoilIon;
526 kinematics.targetMaterial = mat; << 496 kinematics.impactParameter=P;
527 kinematics.a1 = a1; << 497 kinematics.a2=recoilIon->GetPDGMass()/amu_c2;
528 << 498 } else {
529 if (validCollision) { << 499 kinematics.recoilIon=0;
530 G4ScreenedCoulombCrossSection* xsect = Get << 500 kinematics.impactParameter=0;
531 G4ParticleDefinition* recoilIon = xsect->S << 501 kinematics.a2=0;
532 kinematics.crossSection = xsect; << 502 }
533 kinematics.recoilIon = recoilIon; << 503
534 kinematics.impactParameter = P; << 504 std::vector<G4ScreenedCollisionStage *>::iterator stage=collisionStages.begin();
535 kinematics.a2 = recoilIon->GetPDGMass() / << 505
536 } << 506 for(; stage != collisionStages.end(); stage++)
537 else { << 507 (*stage)->DoCollisionStep(this,aTrack, aStep);
538 kinematics.recoilIon = 0; << 508
539 kinematics.impactParameter = 0; << 509 if(registerDepositedEnergy) {
540 kinematics.a2 = 0; << 510 pParticleChange->ProposeLocalEnergyDeposit(IonizingLoss+NIEL);
541 } << 511 pParticleChange->ProposeNonIonizingEnergyDeposit(NIEL);
542 << 512 //MHM G4cout << "depositing energy, total = " << IonizingLoss+NIEL << " NIEL = " << NIEL << G4endl;
543 std::vector<G4ScreenedCollisionStage*>::iter << 513 }
544 << 514
545 for (; stage != collisionStages.end(); stage << 515 return G4VDiscreteProcess::PostStepDoIt( aTrack, aStep );
546 (*stage)->DoCollisionStep(this, aTrack, aS << 516 }
547 << 517
548 if (registerDepositedEnergy) { << 518 G4ScreenedCoulombClassicalKinematics::G4ScreenedCoulombClassicalKinematics() :
549 pParticleChange->ProposeLocalEnergyDeposit << 519 // instantiate all the needed functions statically, so no allocation is done at run time
550 pParticleChange->ProposeNonIonizingEnergyD << 520 // we will be solving x^2 - x phi(x*au)/eps - beta^2 == 0.0
551 // MHM G4cout << "depositing energy, total << 521 // or, for easier scaling, x'^2 - x' au phi(x')/eps - beta^2 au^2
552 //<< IonizingLoss+NIEL << " NIEL = " << NI << 522 // note that only the last of these gets deleted, since it owns the rest
553 } << 523 phifunc(c2.const_plugin_function()),
554 << 524 xovereps(c2.linear(0., 0., 0.)), // will fill this in with the right slope at run time
555 return G4VDiscreteProcess::PostStepDoIt(aTra << 525 diff(c2.quadratic(0., 0., 0., 1.)-xovereps*phifunc)
556 } << 526 {
557 << 527 }
558 G4ScreenedCoulombClassicalKinematics::G4Screen << 528
559 : // instantiate all the needed functions s << 529 G4bool G4ScreenedCoulombClassicalKinematics::DoScreeningComputation(G4ScreenedNuclearRecoil *master,
560 // done at run time << 530 const G4ScreeningTables *screen, G4double eps, G4double beta)
561 // we will be solving x^2 - x phi(x*au)/e << 531 {
562 // or, for easier scaling, x'^2 - x' au p << 532 G4double au=screen->au;
563 // note that only the last of these gets << 533 G4CoulombKinematicsInfo &kin=master->GetKinematics();
564 phifunc(c2.const_plugin_function()), << 534 G4double A=kin.a2;
565 xovereps(c2.linear(0., 0., 0.)), << 535 G4double a1=kin.a1;
566 // will fill this in with the right slope << 536
567 diff(c2.quadratic(0., 0., 0., 1.) - xovere << 537 G4double xx0; // first estimate of closest approach
568 {} << 538 if(eps < 5.0) {
569 << 539 G4double y=std::log(eps);
570 G4bool G4ScreenedCoulombClassicalKinematics::D << 540 G4double mlrho4=((((3.517e-4*y+1.401e-2)*y+2.393e-1)*y+2.734)*y+2.220);
571 << 541 G4double rho4=std::exp(-mlrho4); // W&M eq. 18
572 << 542 G4double bb2=0.5*beta*beta;
573 { << 543 xx0=std::sqrt(bb2+std::sqrt(bb2*bb2+rho4)); // W&M eq. 17
574 G4double au = screen->au; << 544 } else {
575 G4CoulombKinematicsInfo& kin = master->GetKi << 545 G4double ee=1.0/(2.0*eps);
576 G4double A = kin.a2; << 546 xx0=ee+std::sqrt(ee*ee+beta*beta); // W&M eq. 15 (Rutherford value)
577 G4double a1 = kin.a1; << 547 if(master->CheckNuclearCollision(A, a1, xx0*au)) return 0; // nuclei too close
578 << 548
579 G4double xx0; // first estimate of closest << 549 }
580 if (eps < 5.0) { << 550
581 G4double y = std::log(eps); << 551 // we will be solving x^2 - x phi(x*au)/eps - beta^2 == 0.0
582 G4double mlrho4 = ((((3.517e-4 * y + 1.401 << 552 // or, for easier scaling, x'^2 - x' au phi(x')/eps - beta^2 au^2
583 G4double rho4 = std::exp(-mlrho4); // W&M << 553 xovereps.reset(0., 0.0, au/eps); // slope of x*au/eps term
584 G4double bb2 = 0.5 * beta * beta; << 554 phifunc.set_function(&(screen->EMphiData.get())); // install interpolating table
585 xx0 = std::sqrt(bb2 + std::sqrt(bb2 * bb2 << 555 G4double xx1, phip, phip2;
586 } << 556 G4int root_error;
587 else { << 557 xx1=diff->find_root(phifunc.xmin(), std::min(10*xx0*au,phifunc.xmax()),
588 G4double ee = 1.0 / (2.0 * eps); << 558 std::min(xx0*au, phifunc.xmax()), beta*beta*au*au, &root_error, &phip, &phip2)/au;
589 xx0 = ee + std::sqrt(ee * ee + beta * beta << 559
590 if (master->CheckNuclearCollision(A, a1, x << 560 if(root_error) {
591 // nuclei too close << 561 G4cout << "Screened Coulomb Root Finder Error" << G4endl;
592 } << 562 G4cout << "au " << au << " A " << A << " a1 " << a1 << " xx1 " << xx1 << " eps " << eps << " beta " << beta << G4endl;
593 << 563 G4cout << " xmin " << phifunc.xmin() << " xmax " << std::min(10*xx0*au,phifunc.xmax()) ;
594 // we will be solving x^2 - x phi(x*au)/eps << 564 G4cout << " f(xmin) " << phifunc(phifunc.xmin()) << " f(xmax) " << phifunc(std::min(10*xx0*au,phifunc.xmax())) ;
595 // or, for easier scaling, x'^2 - x' au phi( << 565 G4cout << " xstart " << std::min(xx0*au, phifunc.xmax()) << " target " << beta*beta*au*au ;
596 xovereps.reset(0., 0.0, au / eps); // slope << 566 G4cout << G4endl;
597 phifunc.set_function(&(screen->EMphiData.get << 567 throw c2_exception("Failed root find");
598 // install interpolating table << 568 }
599 G4double xx1, phip, phip2; << 569
600 G4int root_error; << 570 // phiprime is scaled by one factor of au because phi is evaluated at (xx0*au),
601 xx1 = diff->find_root(phifunc.xmin(), std::m << 571 G4double phiprime=phip*au;
602 std::min(xx0 * au, phi << 572
603 &phip, &phip2) << 573 //lambda0 is from W&M 19
604 / au; << 574 G4double lambda0=1.0/std::sqrt(0.5+beta*beta/(2.0*xx1*xx1)-phiprime/(2.0*eps));
605 << 575
606 if (root_error) { << 576 //compute the 6-term Lobatto integral alpha (per W&M 21, with different coefficients)
607 G4cout << "Screened Coulomb Root Finder Er << 577 // this is probably completely un-needed but gives the highest quality results,
608 G4cout << "au " << au << " A " << A << " a << 578 G4double alpha=(1.0+ lambda0)/30.0;
609 << " beta " << beta << G4endl; << 579 G4double xvals[]={0.98302349, 0.84652241, 0.53235309, 0.18347974};
610 G4cout << " xmin " << phifunc.xmin() << " << 580 G4double weights[]={0.03472124, 0.14769029, 0.23485003, 0.18602489};
611 G4cout << " f(xmin) " << phifunc(phifunc.x << 581 for(G4int k=0; k<4; k++) {
612 << phifunc(std::min(10 * xx0 * au, << 582 G4double x, ff;
613 G4cout << " xstart " << std::min(xx0 * au, << 583 x=xx1/xvals[k];
614 << beta * beta * au * au; << 584 ff=1.0/std::sqrt(1.0-phifunc(x*au)/(x*eps)-beta*beta/(x*x));
615 G4cout << G4endl; << 585 alpha+=weights[k]*ff;
616 throw c2_exception("Failed root find"); << 586 }
617 } << 587
618 << 588 phifunc.unset_function(); // throws an exception if used without setting again
619 // phiprime is scaled by one factor of au be << 589
620 // at (xx0*au), << 590 G4double thetac1=CLHEP::pi*beta*alpha/xx1; // complement of CM scattering angle
621 G4double phiprime = phip * au; << 591 G4double sintheta=std::sin(thetac1); //note sin(pi-theta)=sin(theta)
622 << 592 G4double costheta=-std::cos(thetac1); // note cos(pi-theta)=-cos(theta)
623 // lambda0 is from W&M 19 << 593 // G4double psi=std::atan2(sintheta, costheta+a1/A); // lab scattering angle (M&T 3rd eq. 8.69)
624 G4double lambda0 = << 594
625 1.0 / std::sqrt(0.5 + beta * beta / (2.0 * << 595 // numerics note: because we checked above for reasonable values of beta which give real recoils,
626 << 596 // we don't have to look too closely for theta -> 0 here (which would cause sin(theta)
627 // compute the 6-term Lobatto integral alpha << 597 // and 1-cos(theta) to both vanish and make the atan2 ill behaved).
628 // different coefficients) << 598 G4double zeta=std::atan2(sintheta, 1-costheta); // lab recoil angle (M&T 3rd eq. 8.73)
629 // this is probably completely un-needed but << 599 G4double coszeta=std::cos(zeta);
630 // quality results, << 600 G4double sinzeta=std::sin(zeta);
631 G4double alpha = (1.0 + lambda0) / 30.0; << 601
632 G4double xvals[] = {0.98302349, 0.84652241, << 602 kin.sinTheta=sintheta;
633 G4double weights[] = {0.03472124, 0.14769029 << 603 kin.cosTheta=costheta;
634 for (G4int k = 0; k < 4; k++) { << 604 kin.sinZeta=sinzeta;
635 G4double x, ff; << 605 kin.cosZeta=coszeta;
636 x = xx1 / xvals[k]; << 606 return 1; // all OK, collision is valid
637 ff = 1.0 / std::sqrt(1.0 - phifunc(x * au) << 607 }
638 alpha += weights[k] * ff; << 608
639 } << 609 void G4ScreenedCoulombClassicalKinematics::DoCollisionStep(G4ScreenedNuclearRecoil *master,
640 << 610 const G4Track& aTrack, const G4Step&) {
641 phifunc.unset_function(); << 611
642 // throws an exception if used without setti << 612 if(!master->GetValidCollision()) return;
643 << 613
644 G4double thetac1 = pi * beta * alpha / xx1; << 614 G4ParticleChange &aParticleChange=master->GetParticleChange();
645 // complement of CM scattering angle << 615 G4CoulombKinematicsInfo &kin=master->GetKinematics();
646 G4double sintheta = std::sin(thetac1); // n << 616
647 G4double costheta = -std::cos(thetac1); // << 617 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
648 // G4double psi=std::atan2(sintheta, costhet << 618 G4ParticleDefinition *baseParticle=aTrack.GetDefinition();
649 // lab scattering angle (M&T 3rd eq. 8.69) << 619
650 << 620 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
651 // numerics note: because we checked above << 621
652 // of beta which give real recoils, << 622 // this adjustment to a1 gives the right results for soft (constant gamma)
653 // we don't have to look too closely for the << 623 // relativistic collisions. Hard collisions are wrong anyway, since the
654 // (which would cause sin(theta) << 624 // Coulombic and hadronic terms interfere and cannot be added.
655 // and 1-cos(theta) to both vanish and make << 625 G4double gamma=(1.0+incidentEnergy/baseParticle->GetPDGMass());
656 G4double zeta = std::atan2(sintheta, 1 - cos << 626 G4double a1=kin.a1*gamma; // relativistic gamma correction
657 // lab recoil angle (M&T 3rd eq. 8.73) << 627
658 G4double coszeta = std::cos(zeta); << 628 G4ParticleDefinition *recoilIon=kin.recoilIon;
659 G4double sinzeta = std::sin(zeta); << 629 G4double A=recoilIon->GetPDGMass()/amu_c2;
660 << 630 G4int Z=(G4int)((recoilIon->GetPDGCharge()/eplus)+0.5);
661 kin.sinTheta = sintheta; << 631
662 kin.cosTheta = costheta; << 632 G4double Ec = incidentEnergy*(A/(A+a1)); // energy in CM frame (non-relativistic!)
663 kin.sinZeta = sinzeta; << 633 const G4ScreeningTables *screen=kin.crossSection->GetScreening(Z);
664 kin.cosZeta = coszeta; << 634 G4double au=screen->au; // screening length
665 return 1; // all OK, collision is valid << 635
666 } << 636 G4double beta = kin.impactParameter/au; // dimensionless impact parameter
667 << 637 G4double eps = Ec/(screen->z1*Z*elm_coupling/au); // dimensionless energy
668 void G4ScreenedCoulombClassicalKinematics::DoC << 638
669 << 639 G4bool ok=DoScreeningComputation(master, screen, eps, beta);
670 { << 640 if(!ok) {
671 if (!master->GetValidCollision()) return; << 641 master->SetValidCollision(0); // flag bad collision
672 << 642 return; // just bail out without setting valid flag
673 G4ParticleChange& aParticleChange = master-> << 643 }
674 G4CoulombKinematicsInfo& kin = master->GetKi << 644
675 << 645 G4double eRecoil=4*incidentEnergy*a1*A*kin.cosZeta*kin.cosZeta/((a1+A)*(a1+A));
676 const G4DynamicParticle* incidentParticle = << 646 kin.eRecoil=eRecoil;
677 G4ParticleDefinition* baseParticle = aTrack. << 647
678 << 648 if(incidentEnergy-eRecoil < master->GetRecoilCutoff()*a1) {
679 G4double incidentEnergy = incidentParticle-> << 649 aParticleChange.ProposeEnergy(0.0);
680 << 650 master->DepositEnergy(int(screen->z1), a1, kin.targetMaterial, incidentEnergy-eRecoil);
681 // this adjustment to a1 gives the right res << 651 }
682 // (constant gamma) << 652
683 // relativistic collisions. Hard collisions << 653 if(master->GetEnableRecoils() && eRecoil > master->GetRecoilCutoff() * kin.a2) {
684 // Coulombic and hadronic terms interfere an << 654 kin.recoilIon=recoilIon;
685 G4double gamma = (1.0 + incidentEnergy / bas << 655 } else {
686 G4double a1 = kin.a1 * gamma; // relativist << 656 kin.recoilIon=0; // this flags no recoil to be generated
687 << 657 master->DepositEnergy(Z, A, kin.targetMaterial, eRecoil) ;
688 G4ParticleDefinition* recoilIon = kin.recoil << 658 }
689 G4double A = recoilIon->GetPDGMass() / amu_c << 659 }
690 G4int Z = (G4int)((recoilIon->GetPDGCharge() << 660
691 << 661 void G4SingleScatter::DoCollisionStep(G4ScreenedNuclearRecoil *master,
692 G4double Ec = incidentEnergy * (A / (A + a1) << 662 const G4Track& aTrack, const G4Step&) {
693 // energy in CM frame (non-relativistic!) << 663
694 const G4ScreeningTables* screen = kin.crossS << 664 if(!master->GetValidCollision()) return;
695 G4double au = screen->au; // screening leng << 665
696 << 666 G4CoulombKinematicsInfo &kin=master->GetKinematics();
697 G4double beta = kin.impactParameter / au; << 667 G4ParticleChange &aParticleChange=master->GetParticleChange();
698 // dimensionless impact parameter << 668
699 G4double eps = Ec / (screen->z1 * Z * elm_co << 669 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
700 // dimensionless energy << 670 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
701 << 671 G4double eRecoil=kin.eRecoil;
702 G4bool ok = DoScreeningComputation(master, s << 672
703 if (!ok) { << 673 G4double azimuth=G4UniformRand()*(2.0*CLHEP::pi);
704 master->SetValidCollision(0); // flag bad << 674 G4double sa=std::sin(azimuth);
705 return; // just bail out without setting << 675 G4double ca=std::cos(azimuth);
706 } << 676
707 << 677 G4ThreeVector recoilMomentumDirection(kin.sinZeta*ca, kin.sinZeta*sa, kin.cosZeta);
708 G4double eRecoil = << 678 G4ParticleMomentum incidentDirection = incidentParticle->GetMomentumDirection();
709 4 * incidentEnergy * a1 * A * kin.cosZeta << 679 recoilMomentumDirection=recoilMomentumDirection.rotateUz(incidentDirection);
710 kin.eRecoil = eRecoil; << 680 G4ThreeVector recoilMomentum=recoilMomentumDirection*std::sqrt(2.0*eRecoil*kin.a2*amu_c2);
711 << 681
712 if (incidentEnergy - eRecoil < master->GetRe << 682 if(aParticleChange.GetEnergy() != 0.0) { // DoKinematics hasn't stopped it!
713 aParticleChange.ProposeEnergy(0.0); << 683 G4ThreeVector beamMomentum=incidentParticle->GetMomentum()-recoilMomentum;
714 master->DepositEnergy(int(screen->z1), a1, << 684 aParticleChange.ProposeMomentumDirection(beamMomentum.unit()) ;
715 } << 685 aParticleChange.ProposeEnergy(incidentEnergy-eRecoil);
716 << 686 }
717 if (master->GetEnableRecoils() && eRecoil > << 687
718 kin.recoilIon = recoilIon; << 688 if(kin.recoilIon) {
719 } << 689 G4DynamicParticle* recoil = new G4DynamicParticle (kin.recoilIon,
720 else { << 690 recoilMomentumDirection,eRecoil) ;
721 kin.recoilIon = 0; // this flags no recoi << 691
722 master->DepositEnergy(Z, A, kin.targetMate << 692 aParticleChange.SetNumberOfSecondaries(1);
723 } << 693 aParticleChange.AddSecondary(recoil);
724 } << 694 }
725 << 695 }
726 void G4SingleScatter::DoCollisionStep(G4Screen << 696
727 const G4 << 697 G4bool G4ScreenedNuclearRecoil::
728 { << 698 IsApplicable(const G4ParticleDefinition& aParticleType)
729 if (!master->GetValidCollision()) return; << 699 {
730 << 700 return aParticleType == *(G4Proton::Proton()) ||
731 G4CoulombKinematicsInfo& kin = master->GetKi << 701 aParticleType.GetParticleType() == "nucleus" ||
732 G4ParticleChange& aParticleChange = master-> << 702 aParticleType.GetParticleType() == "static_nucleus";
733 << 703 }
734 const G4DynamicParticle* incidentParticle = << 704
735 G4double incidentEnergy = incidentParticle-> << 705
736 G4double eRecoil = kin.eRecoil; << 706 void
737 << 707 G4ScreenedNuclearRecoil::
738 G4double azimuth = G4UniformRand() * (2.0 * << 708 DumpPhysicsTable(const G4ParticleDefinition&)
739 G4double sa = std::sin(azimuth); <<
740 G4double ca = std::cos(azimuth); <<
741 <<
742 G4ThreeVector recoilMomentumDirection(kin.si <<
743 G4ParticleMomentum incidentDirection = incid <<
744 recoilMomentumDirection = recoilMomentumDire <<
745 G4ThreeVector recoilMomentum = <<
746 recoilMomentumDirection * std::sqrt(2.0 * <<
747 <<
748 if (aParticleChange.GetEnergy() != 0.0) { <<
749 // DoKinematics hasn't stopped it! <<
750 G4ThreeVector beamMomentum = incidentParti <<
751 aParticleChange.ProposeMomentumDirection(b <<
752 aParticleChange.ProposeEnergy(incidentEner <<
753 } <<
754 <<
755 if (kin.recoilIon) { <<
756 G4DynamicParticle* recoil = <<
757 new G4DynamicParticle(kin.recoilIon, rec <<
758 <<
759 aParticleChange.SetNumberOfSecondaries(1); <<
760 aParticleChange.AddSecondary(recoil); <<
761 } <<
762 } <<
763 <<
764 G4bool G4ScreenedNuclearRecoil::IsApplicable(c <<
765 { <<
766 return aParticleType == *(G4Proton::Proton() <<
767 || aParticleType.GetParticleType() == <<
768 } <<
769 <<
770 void G4ScreenedNuclearRecoil::BuildPhysicsTabl <<
771 { 709 {
772 G4String nam = aParticleType.GetParticleName <<
773 if (nam == "GenericIon" || nam == "proton" | <<
774 || nam == "alpha" || nam == "He3") <<
775 { <<
776 G4cout << G4endl << GetProcessName() << ": <<
777 << " SubType= " << GetProcessSub <<
778 << " maxEnergy(MeV)= " << proces <<
779 } <<
780 } 710 }
781 711
782 void G4ScreenedNuclearRecoil::DumpPhysicsTable <<
783 <<
784 // This used to be the file mhmScreenedNuclear 712 // This used to be the file mhmScreenedNuclearRecoil_native.cc
785 // it has been included here to collect this f << 713 // it has been included here to collect this file into a smaller number of packages
786 // number of packages <<
787 714
788 #include "G4DataVector.hh" 715 #include "G4DataVector.hh"
>> 716 #include "G4Material.hh"
789 #include "G4Element.hh" 717 #include "G4Element.hh"
790 #include "G4ElementVector.hh" <<
791 #include "G4Isotope.hh" 718 #include "G4Isotope.hh"
792 #include "G4Material.hh" <<
793 #include "G4MaterialCutsCouple.hh" 719 #include "G4MaterialCutsCouple.hh"
794 << 720 #include "G4ElementVector.hh"
795 #include <vector> 721 #include <vector>
796 722
797 G4_c2_function& ZBLScreening(G4int z1, G4int z << 723 G4_c2_function &ZBLScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
798 { 724 {
799 static const size_t ncoef = 4; << 725 static const size_t ncoef=4;
800 static G4double scales[ncoef] = {-3.2, -0.94 << 726 static G4double scales[ncoef]={-3.2, -0.9432, -0.4028, -0.2016};
801 static G4double coefs[ncoef] = {0.1818, 0.50 << 727 static G4double coefs[ncoef]={0.1818,0.5099,0.2802,0.0281};
802 << 728
803 G4double au = 0.8854 * angstrom * 0.529 / (s << 729 G4double au=0.8854*angstrom*0.529/(std::pow(z1, 0.23)+std::pow(z2,0.23));
804 std::vector<G4double> r(npoints), phi(npoint << 730 std::vector<G4double> r(npoints), phi(npoints);
805 << 731
806 for (size_t i = 0; i < npoints; i++) { << 732 for(size_t i=0; i<npoints; i++) {
807 G4double rr = (float)i / (float)(npoints - << 733 G4double rr=(float)i/(float)(npoints-1);
808 r[i] = rr * rr * rMax; << 734 r[i]=rr*rr*rMax; // use quadratic r scale to make sampling fine near the center
809 // use quadratic r scale to make sampling << 735 G4double sum=0.0;
810 G4double sum = 0.0; << 736 for(size_t j=0; j<ncoef; j++) sum+=coefs[j]*std::exp(scales[j]*r[i]/au);
811 for (size_t j = 0; j < ncoef; j++) << 737 phi[i]=sum;
812 sum += coefs[j] * std::exp(scales[j] * r << 738 }
813 phi[i] = sum; << 739
814 } << 740 // compute the derivative at the origin for the spline
815 << 741 G4double phiprime0=0.0;
816 // compute the derivative at the origin for << 742 for(size_t j=0; j<ncoef; j++) phiprime0+=scales[j]*coefs[j]*std::exp(scales[j]*r[0]/au);
817 G4double phiprime0 = 0.0; << 743 phiprime0*=(1.0/au); // put back in natural units;
818 for (size_t j = 0; j < ncoef; j++) << 744
819 phiprime0 += scales[j] * coefs[j] * std::e << 745 *auval=au;
820 phiprime0 *= (1.0 / au); // put back in nat << 746 return c2.lin_log_interpolating_function().load(r, phi, false, phiprime0,true,0);
821 << 747 }
822 *auval = au; << 748
823 return c2.lin_log_interpolating_function().l << 749 G4_c2_function &MoliereScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
824 } << 750 {
825 << 751 static const size_t ncoef=3;
826 G4_c2_function& MoliereScreening(G4int z1, G4i << 752 static G4double scales[ncoef]={-6.0, -1.2, -0.3};
827 { << 753 static G4double coefs[ncoef]={0.10, 0.55, 0.35};
828 static const size_t ncoef = 3; << 754
829 static G4double scales[ncoef] = {-6.0, -1.2, << 755 G4double au=0.8853*0.529*angstrom/std::sqrt(std::pow(z1, 0.6667)+std::pow(z2,0.6667));
830 static G4double coefs[ncoef] = {0.10, 0.55, << 756 std::vector<G4double> r(npoints), phi(npoints);
831 << 757
832 G4double au = 0.8853 * 0.529 * angstrom / st << 758 for(size_t i=0; i<npoints; i++) {
833 std::vector<G4double> r(npoints), phi(npoint << 759 G4double rr=(float)i/(float)(npoints-1);
834 << 760 r[i]=rr*rr*rMax; // use quadratic r scale to make sampling fine near the center
835 for (size_t i = 0; i < npoints; i++) { << 761 G4double sum=0.0;
836 G4double rr = (float)i / (float)(npoints - << 762 for(size_t j=0; j<ncoef; j++) sum+=coefs[j]*std::exp(scales[j]*r[i]/au);
837 r[i] = rr * rr * rMax; << 763 phi[i]=sum;
838 // use quadratic r scale to make sampling << 764 }
839 G4double sum = 0.0; << 765
840 for (size_t j = 0; j < ncoef; j++) << 766 // compute the derivative at the origin for the spline
841 sum += coefs[j] * std::exp(scales[j] * r << 767 G4double phiprime0=0.0;
842 phi[i] = sum; << 768 for(size_t j=0; j<ncoef; j++) phiprime0+=scales[j]*coefs[j]*std::exp(scales[j]*r[0]/au);
843 } << 769 phiprime0*=(1.0/au); // put back in natural units;
844 << 770
845 // compute the derivative at the origin for << 771 *auval=au;
846 G4double phiprime0 = 0.0; << 772 return c2.lin_log_interpolating_function().load(r, phi, false, phiprime0,true,0);
847 for (size_t j = 0; j < ncoef; j++) << 773 }
848 phiprime0 += scales[j] * coefs[j] * std::e << 774
849 phiprime0 *= (1.0 / au); // put back in nat << 775 G4_c2_function &LJScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
850 << 776 {
851 *auval = au; << 777 //from Loftager, Besenbacher, Jensen & Sorensen
852 return c2.lin_log_interpolating_function().l << 778 //PhysRev A20, 1443++, 1979
853 } << 779 G4double au=0.8853*0.529*angstrom/std::sqrt(std::pow(z1, 0.6667)+std::pow(z2,0.6667));
854 << 780 std::vector<G4double> r(npoints), phi(npoints);
855 G4_c2_function& LJScreening(G4int z1, G4int z2 << 781
856 { << 782 for(size_t i=0; i<npoints; i++) {
857 // from Loftager, Besenbacher, Jensen & Sore << 783 G4double rr=(float)i/(float)(npoints-1);
858 // PhysRev A20, 1443++, 1979 << 784 r[i]=rr*rr*rMax; // use quadratic r scale to make sampling fine near the center
859 G4double au = 0.8853 * 0.529 * angstrom / st << 785
860 std::vector<G4double> r(npoints), phi(npoint << 786 G4double y=std::sqrt(9.67*r[i]/au);
861 << 787 G4double ysq=y*y;
862 for (size_t i = 0; i < npoints; i++) { << 788 G4double phipoly=1+y+0.3344*ysq+0.0485*y*ysq+0.002647*ysq*ysq;
863 G4double rr = (float)i / (float)(npoints - << 789 phi[i]=phipoly*std::exp(-y);
864 r[i] = rr * rr * rMax; << 790 // G4cout << r[i] << " " << phi[i] << G4endl;
865 // use quadratic r scale to make sampling << 791 }
866 << 792
867 G4double y = std::sqrt(9.67 * r[i] / au); << 793 // compute the derivative at the origin for the spline
868 G4double ysq = y * y; << 794 G4double logphiprime0=(9.67/2.0)*(2*0.3344-1.0); // #avoid 0/0 on first element
869 G4double phipoly = 1 + y + 0.3344 * ysq + << 795 logphiprime0 *= (1.0/au); // #put back in natural units
870 phi[i] = phipoly * std::exp(-y); << 796
871 // G4cout << r[i] << " " << phi[i] << G4en << 797 *auval=au;
872 } << 798 return c2.lin_log_interpolating_function().load(r, phi, false, logphiprime0*phi[0],true,0);
873 << 799 }
874 // compute the derivative at the origin for << 800
875 G4double logphiprime0 = (9.67 / 2.0) * (2 * << 801 G4_c2_function &LJZBLScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
876 // #avoid 0/0 on first element << 802 {
877 logphiprime0 *= (1.0 / au); // #put back in << 803 // hybrid of LJ and ZBL, uses LJ if x < 0.25*auniv, ZBL if x > 1.5*auniv, and
878 << 804 /// connector in between. These numbers are selected so the switchover
879 *auval = au; << 805 // is very near the point where the functions naturally cross.
880 return c2.lin_log_interpolating_function().l << 806 G4double auzbl, aulj;
881 } << 807
882 << 808 c2p zbl=ZBLScreening(z1, z2, npoints, rMax, &auzbl);
883 G4_c2_function& LJZBLScreening(G4int z1, G4int << 809 c2p lj=LJScreening(z1, z2, npoints, rMax, &aulj);
884 { << 810
885 // hybrid of LJ and ZBL, uses LJ if x < 0.25 << 811 G4double au=(auzbl+aulj)*0.5;
886 /// connector in between. These numbers are << 812 lj->set_domain(lj->xmin(), 0.25*au);
887 // is very near the point where the function << 813 zbl->set_domain(1.5*au,zbl->xmax());
888 G4double auzbl, aulj; << 814
889 << 815 c2p conn=c2.connector_function(lj->xmax(), lj, zbl->xmin(), zbl, true,0);
890 c2p zbl = ZBLScreening(z1, z2, npoints, rMax << 816 c2_piecewise_function_p<G4double> &pw=c2.piecewise_function();
891 c2p lj = LJScreening(z1, z2, npoints, rMax, << 817 c2p keepit(pw);
892 << 818 pw.append_function(lj);
893 G4double au = (auzbl + aulj) * 0.5; << 819 pw.append_function(conn);
894 lj->set_domain(lj->xmin(), 0.25 * au); << 820 pw.append_function(zbl);
895 zbl->set_domain(1.5 * au, zbl->xmax()); << 821
896 << 822 *auval=au;
897 c2p conn = c2.connector_function(lj->xmax(), << 823 keepit.release_for_return();
898 c2_piecewise_function_p<G4double>& pw = c2.p << 824 return pw;
899 c2p keepit(pw); << 825 }
900 pw.append_function(lj); << 826
901 pw.append_function(conn); << 827 G4NativeScreenedCoulombCrossSection::~G4NativeScreenedCoulombCrossSection() {
902 pw.append_function(zbl); << 828 }
903 << 829
904 *auval = au; << 830 G4NativeScreenedCoulombCrossSection::G4NativeScreenedCoulombCrossSection() {
905 keepit.release_for_return(); << 831 AddScreeningFunction("zbl", ZBLScreening);
906 return pw; << 832 AddScreeningFunction("lj", LJScreening);
907 } << 833 AddScreeningFunction("mol", MoliereScreening);
908 << 834 AddScreeningFunction("ljzbl", LJZBLScreening);
909 G4NativeScreenedCoulombCrossSection::~G4Native << 835 }
910 << 836
911 G4NativeScreenedCoulombCrossSection::G4NativeS << 837 std::vector<G4String> G4NativeScreenedCoulombCrossSection::GetScreeningKeys() const {
912 { << 838 std::vector<G4String> keys;
913 AddScreeningFunction("zbl", ZBLScreening); << 839 // find the available screening keys
914 AddScreeningFunction("lj", LJScreening); << 840 std::map<std::string, ScreeningFunc>::const_iterator sfunciter=phiMap.begin();
915 AddScreeningFunction("mol", MoliereScreening << 841 for(; sfunciter != phiMap.end(); sfunciter++) keys.push_back((*sfunciter).first);
916 AddScreeningFunction("ljzbl", LJZBLScreening << 842 return keys;
917 } << 843 }
918 << 844
919 std::vector<G4String> G4NativeScreenedCoulombC << 845 static inline G4double cm_energy(G4double a1, G4double a2, G4double t0) {
920 { << 846 // "relativistically correct energy in CM frame"
921 std::vector<G4String> keys; << 847 G4double m1=a1*amu_c2, m2=a2*amu_c2;
922 // find the available screening keys << 848 G4double mc2=(m1+m2);
923 std::map<std::string, ScreeningFunc>::const_ << 849 G4double f=2.0*m2*t0/(mc2*mc2);
924 for (; sfunciter != phiMap.end(); sfunciter+ << 850 // old way: return (f < 1e-6) ? 0.5*mc2*f : mc2*(std::sqrt(1.0+f)-1.0);
925 keys.push_back((*sfunciter).first); << 851 // formally equivalent to previous, but numerically stable for all f without conditional
926 return keys; << 852 // uses identity (sqrt(1+x) - 1)(sqrt(1+x) + 1) = x
927 } << 853 return mc2*f/(std::sqrt(1.0+f)+1.0);
928 << 854 }
929 static inline G4double cm_energy(G4double a1, << 855
930 { << 856 static inline G4double thetac(G4double m1, G4double m2, G4double eratio) {
931 // "relativistically correct energy in CM fr << 857 G4double s2th2=eratio*( (m1+m2)*(m1+m2)/(4.0*m1*m2) );
932 G4double m1 = a1 * amu_c2, mass2 = a2 * amu_ << 858 G4double sth2=std::sqrt(s2th2);
933 G4double mc2 = (m1 + mass2); << 859 return 2.0*std::asin(sth2);
934 G4double f = 2.0 * mass2 * t0 / (mc2 * mc2); << 860 }
935 // old way: return (f < 1e-6) ? 0.5*mc2*f : << 861
936 // formally equivalent to previous, but nume << 862 void G4NativeScreenedCoulombCrossSection::LoadData(G4String screeningKey, G4int z1, G4double a1, G4double recoilCutoff)
937 // f without conditional << 863 {
938 // uses identity (sqrt(1+x) - 1)(sqrt(1+x) + << 864 static const size_t sigLen=200; // since sigma doesn't matter much, a very coarse table will do
939 return mc2 * f / (std::sqrt(1.0 + f) + 1.0); << 865 G4DataVector energies(sigLen);
940 } << 866 G4DataVector data(sigLen);
941 << 867
942 static inline G4double thetac(G4double m1, G4d << 868 a1=standardmass(z1); // use standardized values for mass for building tables
943 { << 869
944 G4double s2th2 = eratio * ((m1 + mass2) * (m << 870 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
945 G4double sth2 = std::sqrt(s2th2); << 871 if (materialTable == 0)
946 return 2.0 * std::asin(sth2); << 872 G4Exception("mhmNativeCrossSection::LoadData - no MaterialTable found)");
947 } << 873
948 << 874 G4int nMaterials = G4Material::GetNumberOfMaterials();
949 void G4NativeScreenedCoulombCrossSection::Load << 875
950 << 876 for (G4int m=0; m<nMaterials; m++)
951 { << 877 {
952 static const size_t sigLen = 200; << 878 const G4Material* material= (*materialTable)[m];
953 // since sigma doesn't matter much, a very c << 879 const G4ElementVector* elementVector = material->GetElementVector();
954 G4DataVector energies(sigLen); << 880 const G4int nMatElements = material->GetNumberOfElements();
955 G4DataVector data(sigLen); << 881
956 << 882 for (G4int iEl=0; iEl<nMatElements; iEl++)
957 a1 = standardmass(z1); << 883 {
958 // use standardized values for mass for buil << 884 G4Element* element = (*elementVector)[iEl];
959 << 885 G4int Z = (G4int) element->GetZ();
960 const G4MaterialTable* materialTable = G4Mat << 886 G4double a2=element->GetA()*(mole/gram);
961 G4int nMaterials = G4Material::GetNumberOfMa << 887
962 << 888 if(sigmaMap.find(Z)!=sigmaMap.end()) continue; // we've already got this element
963 for (G4int im = 0; im < nMaterials; im++) { << 889
964 const G4Material* material = (*materialTab << 890 // find the screening function generator we need
965 const G4ElementVector* elementVector = mat << 891 std::map<std::string, ScreeningFunc>::iterator sfunciter=phiMap.find(screeningKey);
966 const G4int nMatElements = material->GetNu << 892 if(sfunciter==phiMap.end()) {
967 << 893 G4cout << "no such screening key " << screeningKey << G4endl; // FIXME later
968 for (G4int iEl = 0; iEl < nMatElements; iE << 894 exit(1);
969 const G4Element* element = (*elementVect << 895 }
970 G4int Z = element->GetZasInt(); << 896 ScreeningFunc sfunc=(*sfunciter).second;
971 G4double a2 = element->GetA() * (mole / << 897
972 << 898 G4double au;
973 if (sigmaMap.find(Z) != sigmaMap.end()) << 899 G4_c2_ptr screen=sfunc(z1, Z, 200, 50.0*angstrom, &au); // generate the screening data
974 // we've already got this element << 900 G4ScreeningTables st;
975 << 901
976 // find the screening function generator << 902 st.EMphiData=screen; //save our phi table
977 std::map<std::string, ScreeningFunc>::it << 903 st.z1=z1; st.m1=a1; st.z2=Z; st.m2=a2; st.emin=recoilCutoff;
978 if (sfunciter == phiMap.end()) { << 904 st.au=au;
979 G4ExceptionDescription ed; << 905
980 ed << "No such screening key <" << scr << 906 // now comes the hard part... build the total cross section tables from the phi table
981 G4Exception("G4NativeScreenedCoulombCr << 907 //based on (pi-thetac) = pi*beta*alpha/x0, but noting that alpha is very nearly unity, always
982 } << 908 //so just solve it wth alpha=1, which makes the solution much easier
983 ScreeningFunc sfunc = (*sfunciter).secon << 909 //this function returns an approximation to (beta/x0)^2=phi(x0)/(eps*x0)-1 ~ ((pi-thetac)/pi)^2
984 << 910 //Since we don't need exact sigma values, this is good enough (within a factor of 2 almost always)
985 G4double au; << 911 //this rearranges to phi(x0)/(x0*eps) = 2*theta/pi - theta^2/pi^2
986 G4_c2_ptr screen = sfunc(z1, Z, 200, 50. << 912
987 // generate the screening data << 913 c2_linear_p<G4double> &c2eps=c2.linear(0.0, 0.0, 0.0); // will store an appropriate eps inside this in loop
988 G4ScreeningTables st; << 914 G4_c2_ptr phiau=screen(c2.linear(0.0, 0.0, au));
989 << 915 G4_c2_ptr x0func(phiau/c2eps); // this will be phi(x)/(x*eps) when c2eps is correctly set
990 st.EMphiData = screen; // save our phi << 916 x0func->set_domain(1e-6*angstrom/au, 0.9999*screen->xmax()/au); // needed for inverse function
991 st.z1 = z1; << 917 // use the c2_inverse_function interface for the root finder... it is more efficient for an ordered
992 st.m1 = a1; << 918 // computation of values.
993 st.z2 = Z; << 919 G4_c2_ptr x0_solution(c2.inverse_function(x0func));
994 st.m2 = a2; << 920
995 st.emin = recoilCutoff; << 921 G4double m1c2=a1*amu_c2;
996 st.au = au; << 922 G4double escale=z1*Z*elm_coupling/au; // energy at screening distance
997 << 923 G4double emax=m1c2; // model is doubtful in very relativistic range
998 // now comes the hard part... build the << 924 G4double eratkin=0.9999*(4*a1*a2)/((a1+a2)*(a1+a2)); // #maximum kinematic ratio possible at 180 degrees
999 // tables from the phi table << 925 G4double cmfact0=st.emin/cm_energy(a1, a2, st.emin);
1000 // based on (pi-thetac) = pi*beta*alpha << 926 G4double l1=std::log(emax);
1001 // alpha is very nearly unity, always << 927 G4double l0=std::log(st.emin*cmfact0/eratkin);
1002 // so just solve it wth alpha=1, which << 928
1003 // much easier << 929 if(verbosity >=1)
1004 // this function returns an approximati << 930 G4cout << "Native Screening: " << screeningKey << " " << z1 << " " << a1 << " " <<
1005 // (beta/x0)^2=phi(x0)/(eps*x0)-1 ~ ((p << 931 Z << " " << a2 << " " << recoilCutoff << G4endl;
1006 // Since we don't need exact sigma valu << 932
1007 // (within a factor of 2 almost always) << 933 for(size_t idx=0; idx<sigLen; idx++) {
1008 // this rearranges to phi(x0)/(x0*eps) << 934 G4double ee=std::exp(idx*((l1-l0)/sigLen)+l0);
1009 // 2*theta/pi - theta^2/pi^2 << 935 G4double gamma=1.0+ee/m1c2;
1010 << 936 G4double eratio=(cmfact0*st.emin)/ee; // factor by which ee needs to be reduced to get emin
1011 c2_linear_p<G4double>& c2eps = c2.linea << 937 G4double theta=thetac(gamma*a1, a2, eratio);
1012 // will store an appropriate eps inside << 938
1013 G4_c2_ptr phiau = screen(c2.linear(0.0, << 939 G4double eps=cm_energy(a1, a2, ee)/escale; // #make sure lab energy is converted to CM for these calculations
1014 G4_c2_ptr x0func(phiau / c2eps); << 940 c2eps.reset(0.0, 0.0, eps); // set correct slope in this function
1015 // this will be phi(x)/(x*eps) when c2e << 941
1016 x0func->set_domain(1e-6 * angstrom / au << 942 G4double q=theta/pi;
1017 // needed for inverse function << 943 // G4cout << ee << " " << m1c2 << " " << gamma << " " << eps << " " << theta << " " << q << G4endl;
1018 // use the c2_inverse_function interfac << 944 // old way using root finder
1019 // it is more efficient for an ordered << 945 // G4double x0= x0func->find_root(1e-6*angstrom/au, 0.9999*screen.xmax()/au, 1.0, 2*q-q*q);
1020 // computation of values. << 946 // new way using c2_inverse_function which caches useful information so should be a bit faster
1021 G4_c2_ptr x0_solution(c2.inverse_functi << 947 // since we are scanning this in strict order.
1022 << 948 G4double x0=0;
1023 G4double m1c2 = a1 * amu_c2; << 949 try {
1024 G4double escale = z1 * Z * elm_coupling << 950 x0=x0_solution(2*q-q*q);
1025 // energy at screening distance << 951 } catch(c2_exception e) {
1026 G4double emax = m1c2; << 952 G4Exception(
1027 // model is doubtful in very relativist << 953 G4String("G4ScreenedNuclearRecoil: failure in inverse solution to generate MFP Tables: ")+e.what()
1028 G4double eratkin = 0.9999 * (4 * a1 * a << 954 );
1029 // #maximum kinematic ratio possible at << 955 }
1030 G4double cmfact0 = st.emin / cm_energy( << 956 G4double betasquared=x0*x0 - x0*phiau(x0)/eps;
1031 G4double l1 = std::log(emax); << 957 G4double sigma=pi*betasquared*au*au;
1032 G4double l0 = std::log(st.emin * cmfact << 958 energies[idx]=ee;
1033 << 959 data[idx]=sigma;
1034 if (verbosity >= 1) << 960 }
1035 G4cout << "Native Screening: " << scr << 961 screeningData[Z]=st;
1036 << a2 << " " << recoilCutoff < << 962 sigmaMap[Z] = c2.log_log_interpolating_function().load(energies, data, true,0,true,0);
1037 << 963 }
1038 for (size_t idx = 0; idx < sigLen; idx+ << 964 }
1039 G4double ee = std::exp(idx * ((l1 - l <<
1040 G4double gamma = 1.0 + ee / m1c2; <<
1041 G4double eratio = (cmfact0 * st.emin) <<
1042 // factor by which ee needs to be red <<
1043 G4double theta = thetac(gamma * a1, a <<
1044 <<
1045 G4double eps = cm_energy(a1, a2, ee) <<
1046 // #make sure lab energy is converted <<
1047 // calculations <<
1048 c2eps.reset(0.0, 0.0, eps); <<
1049 // set correct slope in this function <<
1050 <<
1051 G4double q = theta / pi; <<
1052 // G4cout << ee << " " << m1c2 << " " <<
1053 // << eps << " " << theta << " " << q <<
1054 // old way using root finder <<
1055 // G4double x0= x0func->find_root(1e- <<
1056 // 0.9999*screen.xmax()/au, 1.0, 2*q- <<
1057 // new way using c2_inverse_function <<
1058 // useful information so should be a <<
1059 // since we are scanning this in stri <<
1060 G4double x0 = 0; <<
1061 try { <<
1062 x0 = x0_solution(2 * q - q * q); <<
1063 } <<
1064 catch (c2_exception&) { <<
1065 G4Exception("G4ScreenedNuclearRecoi <<
1066 "failure in inverse sol <<
1067 } <<
1068 G4double betasquared = x0 * x0 - x0 * <<
1069 G4double sigma = pi * betasquared * a <<
1070 energies[idx] = ee; <<
1071 data[idx] = sigma; <<
1072 } <<
1073 screeningData[Z] = st; <<
1074 sigmaMap[Z] = c2.log_log_interpolating_ <<
1075 } <<
1076 } <<
1077 } 965 }
1078 966