| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
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 // 29 //
>> 30 // G4ScreenedNuclearRecoil.cc,v 1.57 2008/05/07 11:51:26 marcus Exp
>> 31 // GEANT4 tag
>> 32 //
30 // 33 //
31 // Class Description 34 // Class Description
32 // Process for screened electromagnetic nuclea << 35 // Process for screened electromagnetic nuclear elastic scattering;
33 // Physics comes from: 36 // Physics comes from:
34 // Marcus H. Mendenhall and Robert A. Weller, << 37 // Marcus H. Mendenhall and Robert A. Weller,
35 // "Algorithms for the rapid computation o << 38 // "Algorithms for the rapid computation of classical cross
36 // sections for screened Coulomb collision 39 // sections for screened Coulomb collisions "
37 // Nuclear Instruments and Methods in Phy << 40 // Nuclear Instruments and Methods in Physics Research B58 (1991) 11-17
38 // The only input required is a screening func 41 // The only input required is a screening function phi(r/a) which is the ratio
39 // of the actual interatomic potential for two << 42 // of the actual interatomic potential for two atoms with atomic numbers Z1 and Z2,
40 // numbers Z1 and Z2, << 43 // 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 // 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 HardeningFactor)
51 // Hardeni <<
52 // sets what fraction of the events will be ra 52 // sets what fraction of the events will be randomly hardened,
53 // and the factor by which the impact area is 53 // and the factor by which the impact area is reduced for such selected events.
54 // 54 //
55 // 21 November, 2004, Marcus Mendenhall 55 // 21 November, 2004, Marcus Mendenhall
56 // added static_nucleus to IsApplicable 56 // added static_nucleus to IsApplicable
57 // << 57 //
58 // 7 December, 2004, Marcus Mendenhall 58 // 7 December, 2004, Marcus Mendenhall
59 // changed mean free path of stopping particle 59 // changed mean free path of stopping particle from 0.0 to 1.0*nanometer
60 // to avoid new verbose warning about 0 MFP in 60 // to avoid new verbose warning about 0 MFP in 4.6.2p02
61 // << 61 //
62 // 17 December, 2004, Marcus Mendenhall 62 // 17 December, 2004, Marcus Mendenhall
63 // added code to permit screening out overly c << 63 // added code to permit screening out overly close collisions which are
64 // expected to be hadronic, not Coulombic 64 // expected to be hadronic, not Coulombic
65 // 65 //
66 // 19 December, 2004, Marcus Mendenhall 66 // 19 December, 2004, Marcus Mendenhall
67 // massive rewrite to add modular physics stag 67 // massive rewrite to add modular physics stages and plug-in cross section table
68 // computation. This allows one to select (e. << 68 // computation. This allows one to select (e.g.) between the normal external python
69 // python process and an embedded python inter << 69 // process and an embedded python interpreter (which is much faster) for generating
70 // for generating the tables. << 70 // the tables.
71 // It also allows one to switch between sub-sa << 71 // It also allows one to switch between sub-sampled scattering (event biasing) and
72 // and normal scattering, and between non-rela << 72 // normal scattering, and between non-relativistic kinematics and relativistic
73 // relativistic kinematic approximations, with << 73 // kinematic approximations, without having a class for every combination. Further, one can
74 // combination. Further, one can add extra sta << 74 // add extra stages to the scattering, which can implement various book-keeping processes.
75 // implement various book-keeping processes. << 75 //
76 // <<
77 // January 2007, Marcus Mendenhall 76 // January 2007, Marcus Mendenhall
78 // Reorganized heavily for inclusion in Geant4 << 77 // Reorganized heavily for inclusion in Geant4 Core. All modules merged into
79 // one source and header, all historic code re 78 // one source and header, all historic code removed.
80 // << 79 //
81 // Class Description - End 80 // Class Description - End
82 81
83 //....oooOO0OOooo........oooOO0OOooo........oo <<
84 82
85 #include "G4ScreenedNuclearRecoil.hh" << 83 #include <stdio.h>
86 84
87 #include "globals.hh" 85 #include "globals.hh"
88 86
89 #include <stdio.h> << 87 #include "G4ScreenedNuclearRecoil.hh"
90 88
91 const char* G4ScreenedCoulombCrossSectionInfo: << 89 const char* G4ScreenedCoulombCrossSectionInfo::CVSFileVers() { return
92 { << 90 "G4ScreenedNuclearRecoil.cc,v 1.57 2008/05/07 11:51:26 marcus Exp GEANT4 tag ";
93 return "G4ScreenedNuclearRecoil.cc,v 1.57 20 <<
94 } 91 }
95 92
96 #include "c2_factory.hh" << 93 #include "G4ParticleTypes.hh"
97 << 94 #include "G4ParticleTable.hh"
>> 95 #include "G4VParticleChange.hh"
>> 96 #include "G4ParticleChangeForLoss.hh"
98 #include "G4DataVector.hh" 97 #include "G4DataVector.hh"
99 #include "G4DynamicParticle.hh" << 98 #include "G4Track.hh"
>> 99 #include "G4Step.hh"
>> 100
>> 101 #include "G4Material.hh"
100 #include "G4Element.hh" 102 #include "G4Element.hh"
101 #include "G4ElementVector.hh" <<
102 #include "G4EmProcessSubType.hh" <<
103 #include "G4IonTable.hh" <<
104 #include "G4Isotope.hh" 103 #include "G4Isotope.hh"
105 #include "G4IsotopeVector.hh" <<
106 #include "G4LindhardPartition.hh" <<
107 #include "G4Material.hh" <<
108 #include "G4MaterialCutsCouple.hh" 104 #include "G4MaterialCutsCouple.hh"
109 #include "G4ParticleChangeForLoss.hh" << 105 #include "G4ElementVector.hh"
>> 106 #include "G4IsotopeVector.hh"
>> 107
>> 108 #include "G4EmProcessSubType.hh"
>> 109
>> 110 #include "G4RangeTest.hh"
110 #include "G4ParticleDefinition.hh" 111 #include "G4ParticleDefinition.hh"
111 #include "G4ParticleTable.hh" << 112 #include "G4DynamicParticle.hh"
112 #include "G4ParticleTypes.hh" <<
113 #include "G4ProcessManager.hh" 113 #include "G4ProcessManager.hh"
114 #include "G4StableIsotopes.hh" 114 #include "G4StableIsotopes.hh"
115 #include "G4Step.hh" << 115 #include "G4LindhardPartition.hh"
116 #include "G4Track.hh" << 116
117 #include "G4VParticleChange.hh" << 117 #include "G4PhysicalConstants.hh"
>> 118 #include "G4SystemOfUnits.hh"
118 #include "Randomize.hh" 119 #include "Randomize.hh"
119 120
120 #include <iomanip> <<
121 #include <iostream> 121 #include <iostream>
122 static c2_factory<G4double> c2; // this makes << 122 #include <iomanip>
>> 123
>> 124 #include "c2_factory.hh"
>> 125 static c2_factory<G4double> c2; // this makes a lot of notation shorter
123 typedef c2_ptr<G4double> c2p; 126 typedef c2_ptr<G4double> c2p;
124 127
125 G4ScreenedCoulombCrossSection::~G4ScreenedCoul 128 G4ScreenedCoulombCrossSection::~G4ScreenedCoulombCrossSection()
126 { 129 {
127 screeningData.clear(); << 130 screeningData.clear();
128 MFPTables.clear(); << 131 MFPTables.clear();
129 } 132 }
130 133
131 const G4double G4ScreenedCoulombCrossSection:: << 134 const G4double G4ScreenedCoulombCrossSection::massmap[nMassMapElements+1]={
132 0, 1.007940, 4.002602, 6.941000 << 135 0, 1.007940, 4.002602, 6.941000, 9.012182, 10.811000, 12.010700,
133 15.999400, 18.998403, 20.179700, 22.98977 << 136 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 << 137 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 << 138 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 << 139 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 << 140 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 << 141 107.868200, 112.411000, 114.818000, 118.710000, 121.760000, 127.600000, 126.904470, 131.293000,
139 137.327000, 138.905500, 140.116000, 140.9076 << 142 132.905450, 137.327000, 138.905500, 140.116000, 140.907650, 144.240000, 145.000000, 150.360000,
140 157.250000, 158.925340, 162.500000, 164.9303 << 143 151.964000, 157.250000, 158.925340, 162.500000, 164.930320, 167.259000, 168.934210, 173.040000,
141 178.490000, 180.947900, 183.840000, 186.2070 << 144 174.967000, 178.490000, 180.947900, 183.840000, 186.207000, 190.230000, 192.217000, 195.078000,
142 200.590000, 204.383300, 207.200000, 208.9803 << 145 196.966550, 200.590000, 204.383300, 207.200000, 208.980380, 209.000000, 210.000000, 222.000000,
143 226.000000, 227.000000, 232.038100, 231.0358 << 146 223.000000, 226.000000, 227.000000, 232.038100, 231.035880, 238.028910, 237.000000, 244.000000,
144 247.000000, 247.000000, 251.000000, 252.0000 << 147 243.000000, 247.000000, 247.000000, 251.000000, 252.000000, 257.000000, 258.000000, 259.000000,
145 261.000000, 262.000000, 266.000000, 264.0000 << 148 262.000000, 261.000000, 262.000000, 266.000000, 264.000000, 277.000000, 268.000000, 281.000000,
146 285.000000, 282.500000, 289.000000, 287.5000 << 149 272.000000, 285.000000, 282.500000, 289.000000, 287.500000, 292.000000};
147 << 150
148 G4ParticleDefinition* << 151 G4ParticleDefinition* G4ScreenedCoulombCrossSection::SelectRandomUnweightedTarget(const G4MaterialCutsCouple* couple)
149 G4ScreenedCoulombCrossSection::SelectRandomUnw << 152 {
150 { << 153 // Select randomly an element within the material, according to number density only
151 // Select randomly an element within the mat << 154 const G4Material* material = couple->GetMaterial();
152 // density only << 155 G4int nMatElements = material->GetNumberOfElements();
153 const G4Material* material = couple->GetMate << 156 const G4ElementVector* elementVector = material->GetElementVector();
154 G4int nMatElements = material->GetNumberOfEl << 157 const G4Element *element=0;
155 const G4ElementVector* elementVector = mater << 158 G4ParticleDefinition*target=0;
156 const G4Element* element = 0; << 159
157 G4ParticleDefinition* target = 0; << 160 // Special case: the material consists of one element
158 << 161 if (nMatElements == 1)
159 // Special case: the material consists of on << 162 {
160 if (nMatElements == 1) { << 163 element= (*elementVector)[0];
161 element = (*elementVector)[0]; << 164 }
162 } << 165 else
163 else { << 166 {
164 // Composite material << 167 // Composite material
165 G4double random = G4UniformRand() * materi << 168 G4double random = G4UniformRand() * material->GetTotNbOfAtomsPerVolume();
166 G4double nsum = 0.0; << 169 G4double nsum=0.0;
167 const G4double* atomDensities = material-> << 170 const G4double *atomDensities=material->GetVecNbOfAtomsPerVolume();
168 << 171
169 for (G4int k = 0; k < nMatElements; k++) { << 172 for (G4int k=0 ; k < nMatElements ; k++ )
170 nsum += atomDensities[k]; << 173 {
171 element = (*elementVector)[k]; << 174 nsum+=atomDensities[k];
172 if (nsum >= random) break; << 175 element= (*elementVector)[k];
173 } << 176 if (nsum >= random) break;
174 } << 177 }
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 } 178 }
213 } <<
214 179
215 // get the official definition of this nucle << 180 G4int N=0;
216 // value of A note that GetIon is very slow, << 181 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
217 // we have already found ourselves. << 182
218 ParticleCache::iterator p = targetMap.find(Z << 183 G4int nIsotopes=element->GetNumberOfIsotopes();
219 if (p != targetMap.end()) { << 184 if(!nIsotopes) {
220 target = (*p).second; << 185 if(Z<=92) {
221 } << 186 // we have no detailed material isotopic info available,
222 else { << 187 // so use G4StableIsotopes table up to Z=92
223 target = G4IonTable::GetIonTable()->GetIon << 188 static G4StableIsotopes theIso; // get a stable isotope table for default results
224 targetMap[Z * 1000 + N] = target; << 189 nIsotopes=theIso.GetNumberOfIsotopes(Z);
225 } << 190 G4double random = 100.0*G4UniformRand(); // values are expressed as percent, sum is 100
226 return target; << 191 G4int tablestart=theIso.GetFirstIsotope(Z);
>> 192 G4double asum=0.0;
>> 193 for(G4int i=0; i<nIsotopes; i++) {
>> 194 asum+=theIso.GetAbundance(i+tablestart);
>> 195 N=theIso.GetIsotopeNucleonCount(i+tablestart);
>> 196 if(asum >= random) break;
>> 197 }
>> 198 } else {
>> 199 // too heavy for stable isotope table, just use mean mass
>> 200 N=(G4int)std::floor(element->GetN()+0.5);
>> 201 }
>> 202 } else {
>> 203 G4int i;
>> 204 const G4IsotopeVector *isoV=element->GetIsotopeVector();
>> 205 G4double random = G4UniformRand();
>> 206 G4double *abundance=element->GetRelativeAbundanceVector();
>> 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 }
>> 213 }
>> 214
>> 215 // get the official definition of this nucleus, to get the correct value of A
>> 216 // note that GetIon is very slow, so we will cache ones we have already found ourselves.
>> 217 ParticleCache::iterator p=targetMap.find(Z*1000+N);
>> 218 if (p != targetMap.end()) {
>> 219 target=(*p).second;
>> 220 } else{
>> 221 target=G4ParticleTable::GetParticleTable()->GetIon(Z, N, 0.0);
>> 222 targetMap[Z*1000+N]=target;
>> 223 }
>> 224 return target;
227 } 225 }
228 226
229 void G4ScreenedCoulombCrossSection::BuildMFPTa 227 void G4ScreenedCoulombCrossSection::BuildMFPTables()
230 { 228 {
231 const G4int nmfpvals = 200; << 229 const G4int nmfpvals=200;
232 230
233 std::vector<G4double> evals(nmfpvals), mfpva << 231 std::vector<G4double> evals(nmfpvals), mfpvals(nmfpvals);
234 232
235 // sum up inverse MFPs per element for each << 233 // sum up inverse MFPs per element for each material
236 const G4MaterialTable* materialTable = G4Mat << 234 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
237 if (materialTable == 0) { << 235 if (materialTable == 0) { return; }
238 return; << 236 //G4Exception("G4ScreenedCoulombCrossSection::BuildMFPTables - no MaterialTable found)");
239 } << 237
240 // G4Exception("G4ScreenedCoulombCrossSectio << 238 G4int nMaterials = G4Material::GetNumberOfMaterials();
241 //- no MaterialTable found)"); << 239
242 << 240 for (G4int matidx=0; matidx < nMaterials; matidx++) {
243 G4int nMaterials = G4Material::GetNumberOfMa << 241
244 << 242 const G4Material* material= (*materialTable)[matidx];
245 for (G4int matidx = 0; matidx < nMaterials; << 243 const G4ElementVector &elementVector = *(material->GetElementVector());
246 const G4Material* material = (*materialTab << 244 const G4int nMatElements = material->GetNumberOfElements();
247 const G4ElementVector& elementVector = *(m << 245
248 const G4int nMatElements = material->GetNu << 246 const G4Element *element=0;
249 << 247 const G4double *atomDensities=material->GetVecNbOfAtomsPerVolume();
250 const G4Element* element = 0; << 248
251 const G4double* atomDensities = material-> << 249 G4double emin=0, emax=0; // find innermost range of cross section functions
252 << 250 for (G4int kel=0 ; kel < nMatElements ; kel++ )
253 G4double emin = 0, emax = 0; << 251 {
254 // find innermost range of cross section f << 252 element=elementVector[kel];
255 for (G4int kel = 0; kel < nMatElements; ke << 253 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
256 element = elementVector[kel]; << 254 const G4_c2_function &ifunc=sigmaMap[Z];
257 G4int Z = (G4int)std::floor(element->Get << 255 if(!kel || ifunc.xmin() > emin) emin=ifunc.xmin();
258 const G4_c2_function& ifunc = sigmaMap[Z << 256 if(!kel || ifunc.xmax() < emax) emax=ifunc.xmax();
259 if (!kel || ifunc.xmin() > emin) emin = << 257 }
260 if (!kel || ifunc.xmax() < emax) emax = << 258
261 } << 259 G4double logint=std::log(emax/emin) / (nmfpvals-1) ; // logarithmic increment for tables
262 << 260
263 G4double logint = std::log(emax / emin) / << 261 // compute energy scale for interpolator. Force exact values at both ends to avoid range errors
264 // logarithmic increment for tables << 262 for (G4int i=1; i<nmfpvals-1; i++) evals[i]=emin*std::exp(logint*i);
265 << 263 evals.front()=emin;
266 // compute energy scale for interpolator. << 264 evals.back()=emax;
267 // both ends to avoid range errors << 265
268 for (G4int i = 1; i < nmfpvals - 1; i++) << 266 // zero out the inverse mfp sums to start
269 evals[i] = emin * std::exp(logint * i); << 267 for (G4int eidx=0; eidx < nmfpvals; eidx++) mfpvals[eidx] = 0.0;
270 evals.front() = emin; << 268
271 evals.back() = emax; << 269 // sum inverse mfp for each element in this material and for each energy
272 << 270 for (G4int kel=0 ; kel < nMatElements ; kel++ )
273 // zero out the inverse mfp sums to start << 271 {
274 for (G4int eidx = 0; eidx < nmfpvals; eidx << 272 element=elementVector[kel];
275 mfpvals[eidx] = 0.0; << 273 G4int Z=(G4int)std::floor(element->GetZ()+0.5);
276 << 274 const G4_c2_function &sigma=sigmaMap[Z];
277 // sum inverse mfp for each element in thi << 275 G4double ndens = atomDensities[kel]; // compute atom fraction for this element in this material
278 // energy << 276
279 for (G4int kel = 0; kel < nMatElements; ke << 277 for (G4int eidx=0; eidx < nmfpvals; eidx++) {
280 element = elementVector[kel]; << 278 mfpvals[eidx] += ndens*sigma(evals[eidx]);
281 G4int Z = (G4int)std::floor(element->Get << 279 }
282 const G4_c2_function& sigma = sigmaMap[Z << 280 }
283 G4double ndens = atomDensities[kel]; << 281
284 // compute atom fraction for this elemen << 282 // convert inverse mfp to regular mfp
285 << 283 for (G4int eidx=0; eidx < nmfpvals; eidx++) {
286 for (G4int eidx = 0; eidx < nmfpvals; ei << 284 mfpvals[eidx] = 1.0/mfpvals[eidx];
287 mfpvals[eidx] += ndens * sigma(evals[e << 285 }
288 } << 286 // and make a new interpolating function out of the sum
>> 287 MFPTables[matidx] = c2.log_log_interpolating_function().load(evals, mfpvals,true,0,true,0);
289 } 288 }
>> 289 }
290 290
291 // convert inverse mfp to regular mfp << 291 G4ScreenedNuclearRecoil::
292 for (G4int eidx = 0; eidx < nmfpvals; eidx << 292 G4ScreenedNuclearRecoil(const G4String& processName,
293 mfpvals[eidx] = 1.0 / mfpvals[eidx]; << 293 const G4String &ScreeningKey,
294 } << 294 G4bool GenerateRecoils,
295 // and make a new interpolating function o << 295 G4double RecoilCutoff, G4double PhysicsCutoff) :
296 MFPTables[matidx] = c2.log_log_interpolati << 296 G4VDiscreteProcess(processName),
297 } << 297 screeningKey(ScreeningKey),
298 } << 298 generateRecoils(GenerateRecoils), avoidReactions(1),
299 << 299 recoilCutoff(RecoilCutoff), physicsCutoff(PhysicsCutoff),
300 G4ScreenedNuclearRecoil::G4ScreenedNuclearReco << 300 hardeningFraction(0.0), hardeningFactor(1.0),
301 << 301 externalCrossSectionConstructor(0),
302 << 302 NIELPartitionFunction(new G4LindhardRobinsonPartition)
303 << 303 {
304 : G4VDiscreteProcess(processName, fElectroma << 304 // for now, point to class instance of this. Doing it by creating a new one fails
305 screeningKey(ScreeningKey), << 305 // to correctly update NIEL
306 generateRecoils(GenerateRecoils), << 306 // not even this is needed... done in G4VProcess().
307 avoidReactions(1), << 307 // pParticleChange=&aParticleChange;
308 recoilCutoff(RecoilCutoff), << 308 processMaxEnergy=50000.0*MeV;
309 physicsCutoff(PhysicsCutoff), << 309 highEnergyLimit=100.0*MeV;
310 hardeningFraction(0.0), << 310 lowEnergyLimit=physicsCutoff;
311 hardeningFactor(1.0), << 311 registerDepositedEnergy=1; // by default, don't hide NIEL
312 externalCrossSectionConstructor(0), << 312 MFPScale=1.0;
313 NIELPartitionFunction(new G4LindhardRobins << 313 // SetVerboseLevel(2);
314 { << 314 AddStage(new G4ScreenedCoulombClassicalKinematics);
315 // for now, point to class instance of this. << 315 AddStage(new G4SingleScatter);
316 // one fails << 316 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 } 317 }
330 318
331 void G4ScreenedNuclearRecoil::ResetTables() 319 void G4ScreenedNuclearRecoil::ResetTables()
332 { 320 {
333 std::map<G4int, G4ScreenedCoulombCrossSectio << 321
334 for (; xt != crossSectionHandlers.end(); xt+ << 322 std::map<G4int, G4ScreenedCoulombCrossSection*>::iterator xt=crossSectionHandlers.begin();
335 delete (*xt).second; << 323 for(;xt != crossSectionHandlers.end(); xt++) {
336 } << 324 delete (*xt).second;
337 crossSectionHandlers.clear(); << 325 }
>> 326 crossSectionHandlers.clear();
338 } 327 }
339 328
340 void G4ScreenedNuclearRecoil::ClearStages() 329 void G4ScreenedNuclearRecoil::ClearStages()
341 { 330 {
342 // I don't think I like deleting the process << 331 // I don't think I like deleting the processes here... they are better abandoned
343 // abandoned << 332 // if the creator doesn't get rid of them
344 // if the creator doesn't get rid of them << 333 // std::vector<G4ScreenedCollisionStage *>::iterator stage=collisionStages.begin();
345 // std::vector<G4ScreenedCollisionStage *>:: << 334 //for(; stage != collisionStages.end(); stage++) delete (*stage);
346 // collisionStages.begin(); <<
347 // for(; stage != collisionStages.end(); sta <<
348 335
349 collisionStages.clear(); << 336 collisionStages.clear();
350 } 337 }
351 338
352 void G4ScreenedNuclearRecoil::SetNIELPartition << 339 void G4ScreenedNuclearRecoil::SetNIELPartitionFunction(const G4VNIELPartition *part)
353 { 340 {
354 if (NIELPartitionFunction) delete NIELPartit << 341 if(NIELPartitionFunction) delete NIELPartitionFunction;
355 NIELPartitionFunction = part; << 342 NIELPartitionFunction=part;
356 } 343 }
357 344
358 void G4ScreenedNuclearRecoil::DepositEnergy(G4 << 345 void G4ScreenedNuclearRecoil::DepositEnergy(G4int z1, G4double a1, const G4Material *material, G4double energy)
359 G4 <<
360 { 346 {
361 if (!NIELPartitionFunction) { << 347 if(!NIELPartitionFunction) {
362 IonizingLoss += energy; << 348 IonizingLoss+=energy;
363 } << 349 } else {
364 else { << 350 G4double part=NIELPartitionFunction->PartitionNIEL(z1, a1, material, energy);
365 G4double part = NIELPartitionFunction->Par << 351 IonizingLoss+=energy*(1-part);
366 IonizingLoss += energy * (1 - part); << 352 NIEL += energy*part;
367 NIEL += energy * part; << 353 }
368 } <<
369 } 354 }
370 355
371 G4ScreenedNuclearRecoil::~G4ScreenedNuclearRec 356 G4ScreenedNuclearRecoil::~G4ScreenedNuclearRecoil()
372 { 357 {
373 ResetTables(); << 358 ResetTables();
374 } 359 }
375 360
376 // returns true if it appears the nuclei colli << 361 // returns true if it appears the nuclei collided, and we are interested in checking
377 // in checking << 362 G4bool G4ScreenedNuclearRecoil::CheckNuclearCollision(
378 G4bool G4ScreenedNuclearRecoil::CheckNuclearCo << 363 G4double A, G4double a1, G4double apsis) {
379 { << 364 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 << 365 // nuclei are within 1.4 fm (reduced pion Compton wavelength) of each other at apsis,
381 && (apsis < (1.1 * (std::pow(A, 1.0 / << 366 // this is hadronic, skip it
382 // nuclei are within 1.4 fm (reduced pion Co <<
383 // other at apsis, <<
384 // this is hadronic, skip it <<
385 } 367 }
386 368
387 G4ScreenedCoulombCrossSection* G4ScreenedNucle << 369 G4ScreenedCoulombCrossSection *G4ScreenedNuclearRecoil::GetNewCrossSectionHandler(void) {
388 { << 370 G4ScreenedCoulombCrossSection *xc;
389 G4ScreenedCoulombCrossSection* xc; << 371 if(!externalCrossSectionConstructor) xc=new G4NativeScreenedCoulombCrossSection;
390 if (!externalCrossSectionConstructor) << 372 else xc=externalCrossSectionConstructor->create();
391 xc = new G4NativeScreenedCoulombCrossSecti << 373 xc->SetVerbosity(verboseLevel);
392 else << 374 return xc;
393 xc = externalCrossSectionConstructor->crea <<
394 xc->SetVerbosity(verboseLevel); <<
395 return xc; <<
396 } 375 }
397 376
398 G4double G4ScreenedNuclearRecoil::GetMeanFreeP << 377 G4double G4ScreenedNuclearRecoil::GetMeanFreePath(const G4Track& track,
>> 378 G4double,
399 379 G4ForceCondition* cond)
400 { 380 {
401 const G4DynamicParticle* incoming = track.Ge << 381 const G4DynamicParticle* incoming = track.GetDynamicParticle();
402 G4double energy = incoming->GetKineticEnergy << 382 G4double energy = incoming->GetKineticEnergy();
403 G4double a1 = incoming->GetDefinition()->Get << 383 G4double a1=incoming->GetDefinition()->GetPDGMass()/amu_c2;
404 << 384
405 G4double meanFreePath; << 385 G4double meanFreePath;
406 *cond = NotForced; << 386 *cond=NotForced;
407 << 387
408 if (energy < lowEnergyLimit || energy < reco << 388 if (energy < lowEnergyLimit || energy < recoilCutoff*a1) {
409 *cond = Forced; << 389 *cond=Forced;
410 return 1.0 * nm; << 390 return 1.0*nm; /* catch and stop slow particles to collect their NIEL! */
411 /* catch and stop slow particles to collec << 391 } else if (energy > processMaxEnergy*a1) {
412 } << 392 return DBL_MAX; // infinite mean free path
413 else if (energy > processMaxEnergy * a1) { << 393 } else if (energy > highEnergyLimit*a1) energy=highEnergyLimit*a1; /* constant MFP at high energy */
414 return DBL_MAX; // infinite mean free pat << 394
415 } << 395 G4double fz1=incoming->GetDefinition()->GetPDGCharge();
416 else if (energy > highEnergyLimit * a1) << 396 G4int z1=(G4int)(fz1/eplus + 0.5);
417 energy = highEnergyLimit * a1; << 397
418 /* constant MFP at high energy */ << 398 std::map<G4int, G4ScreenedCoulombCrossSection*>::iterator xh=
419 << 399 crossSectionHandlers.find(z1);
420 G4double fz1 = incoming->GetDefinition()->Ge << 400 G4ScreenedCoulombCrossSection *xs;
421 G4int z1 = (G4int)(fz1 / eplus + 0.5); << 401
422 << 402 if (xh==crossSectionHandlers.end()) {
423 std::map<G4int, G4ScreenedCoulombCrossSectio << 403 xs =crossSectionHandlers[z1]=GetNewCrossSectionHandler();
424 G4ScreenedCoulombCrossSection* xs; << 404 xs->LoadData(screeningKey, z1, a1, physicsCutoff);
425 << 405 xs->BuildMFPTables();
426 if (xh == crossSectionHandlers.end()) { << 406 } else xs=(*xh).second;
427 xs = crossSectionHandlers[z1] = GetNewCros << 407
428 xs->LoadData(screeningKey, z1, a1, physics << 408 const G4MaterialCutsCouple* materialCouple = track.GetMaterialCutsCouple();
429 xs->BuildMFPTables(); << 409 size_t materialIndex = materialCouple->GetMaterial()->GetIndex();
430 } << 410
431 else << 411 const G4_c2_function &mfp=*(*xs)[materialIndex];
432 xs = (*xh).second; << 412
433 << 413 // make absolutely certain we don't get an out-of-range energy
434 const G4MaterialCutsCouple* materialCouple = << 414 meanFreePath = mfp(std::min(std::max(energy, mfp.xmin()), mfp.xmax()));
435 size_t materialIndex = materialCouple->GetMa << 415
436 << 416 // G4cout << "MFP: " << meanFreePath << " index " << materialIndex << " energy " << energy << " MFPScale " << MFPScale << G4endl;
437 const G4_c2_function& mfp = *(*xs)[materialI << 417
438 << 418 return meanFreePath*MFPScale;
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 } 419 }
447 420
448 G4VParticleChange* G4ScreenedNuclearRecoil::Po 421 G4VParticleChange* G4ScreenedNuclearRecoil::PostStepDoIt(const G4Track& aTrack, const G4Step& aStep)
449 { 422 {
450 validCollision = 1; << 423 validCollision=1;
451 pParticleChange->Initialize(aTrack); << 424 pParticleChange->Initialize(aTrack);
452 NIEL = 0.0; // default is no NIEL deposited << 425 NIEL=0.0; // default is no NIEL deposited
453 IonizingLoss = 0.0; << 426 IonizingLoss=0.0;
454 << 427
455 // do universal setup << 428 // do universal setup
456 << 429
457 const G4DynamicParticle* incidentParticle = << 430 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
458 G4ParticleDefinition* baseParticle = aTrack. << 431 G4ParticleDefinition *baseParticle=aTrack.GetDefinition();
459 << 432
460 G4double fz1 = baseParticle->GetPDGCharge() << 433 G4double fz1=baseParticle->GetPDGCharge()/eplus;
461 G4int z1 = (G4int)(fz1 + 0.5); << 434 G4int z1=(G4int)(fz1+0.5);
462 G4double a1 = baseParticle->GetPDGMass() / a << 435 G4double a1=baseParticle->GetPDGMass()/amu_c2;
463 G4double incidentEnergy = incidentParticle-> << 436 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
464 << 437
465 // Select randomly one element and (possibly << 438 // Select randomly one element and (possibly) isotope in the current material.
466 // current material. << 439 const G4MaterialCutsCouple* couple = aTrack.GetMaterialCutsCouple();
467 const G4MaterialCutsCouple* couple = aTrack. << 440
468 << 441 const G4Material* mat = couple->GetMaterial();
469 const G4Material* mat = couple->GetMaterial( << 442
470 << 443 G4double P=0.0; // the impact parameter of this collision
471 G4double P = 0.0; // the impact parameter o << 444
472 << 445 if(incidentEnergy < GetRecoilCutoff()*a1) { // check energy sanity on entry
473 if (incidentEnergy < GetRecoilCutoff() * a1) << 446 DepositEnergy(z1, baseParticle->GetPDGMass()/amu_c2, mat, incidentEnergy);
474 // check energy sanity on entry << 447 GetParticleChange().ProposeEnergy(0.0);
475 DepositEnergy(z1, baseParticle->GetPDGMass << 448 // stop the particle and bail out
476 GetParticleChange().ProposeEnergy(0.0); << 449 validCollision=0;
477 // stop the particle and bail out << 450 } else {
478 validCollision = 0; << 451
479 } << 452 G4double numberDensity=mat->GetTotNbOfAtomsPerVolume();
480 else { << 453 G4double lattice=0.5/std::pow(numberDensity,1.0/3.0); // typical lattice half-spacing
481 G4double numberDensity = mat->GetTotNbOfAt << 454 G4double length=GetCurrentInteractionLength();
482 G4double lattice = 0.5 / std::pow(numberDe << 455 G4double sigopi=1.0/(CLHEP::pi*numberDensity*length); // this is sigma0/pi
483 // typical lattice half-spacing << 456
484 G4double length = GetCurrentInteractionLen << 457 // 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 << 458 // this is the TRIM method for determining an impact parameter based on the flight path
486 // this is sigma0/pi << 459 // this gives a cumulative distribution of N(P)= 1-exp(-pi P^2 n l)
487 << 460 // 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 << 461 // which may be reasonable
489 // as too far away, little effort is waste << 462 if(sigopi < lattice*lattice) {
490 // this is the TRIM method for determining << 463 // normal long-flight approximation
491 // based on the flight path << 464 P = std::sqrt(-std::log(G4UniformRand()) *sigopi);
492 // this gives a cumulative distribution of << 465 } else {
493 // N(P)= 1-exp(-pi P^2 n l) << 466 // short-flight limit
494 // which says the probability of NOT hitti << 467 P = std::sqrt(G4UniformRand())*lattice;
495 // sigma= pi P^2 =exp(-sigma N l) << 468 }
496 // which may be reasonable << 469
497 if (sigopi < lattice * lattice) { << 470 G4double fraction=GetHardeningFraction();
498 // normal long-flight approximation << 471 if(fraction && G4UniformRand() < fraction) {
499 P = std::sqrt(-std::log(G4UniformRand()) << 472 // pick out some events, and increase the central cross section
500 } << 473 // by reducing the impact parameter
501 else { << 474 P /= std::sqrt(GetHardeningFactor());
502 // short-flight limit << 475 }
503 P = std::sqrt(G4UniformRand()) * lattice << 476
504 } << 477
505 << 478 // check if we are far enough away that the energy transfer must be below cutoff,
506 G4double fraction = GetHardeningFraction() << 479 // and leave everything alone if so, saving a lot of time.
507 if (fraction && G4UniformRand() < fraction << 480 if(P*P > sigopi) {
508 // pick out some events, and increase th << 481 if(GetVerboseLevel() > 1)
509 // section by reducing the impact parame << 482 printf("ScreenedNuclear impact reject: length=%.3f P=%.4f limit=%.4f\n",
510 P /= std::sqrt(GetHardeningFactor()); << 483 length/angstrom, P/angstrom,std::sqrt(sigopi)/angstrom);
511 } << 484 // no collision, don't follow up with anything
512 << 485 validCollision=0;
513 // check if we are far enough away that th << 486 }
514 // must be below cutoff, << 487 }
515 // and leave everything alone if so, savin << 488
516 if (P * P > sigopi) { << 489 // find out what we hit, and record it in our kinematics block.
517 if (GetVerboseLevel() > 1) << 490 kinematics.targetMaterial=mat;
518 printf("ScreenedNuclear impact reject: << 491 kinematics.a1=a1;
519 P / angstrom, std::sqrt(sigopi) << 492
520 // no collision, don't follow up with an << 493 if(validCollision) {
521 validCollision = 0; << 494 G4ScreenedCoulombCrossSection *xsect=GetCrossSectionHandlers()[z1];
522 } << 495 G4ParticleDefinition *recoilIon=
523 } << 496 xsect->SelectRandomUnweightedTarget(couple);
>> 497 kinematics.crossSection=xsect;
>> 498 kinematics.recoilIon=recoilIon;
>> 499 kinematics.impactParameter=P;
>> 500 kinematics.a2=recoilIon->GetPDGMass()/amu_c2;
>> 501 } else {
>> 502 kinematics.recoilIon=0;
>> 503 kinematics.impactParameter=0;
>> 504 kinematics.a2=0;
>> 505 }
>> 506
>> 507 std::vector<G4ScreenedCollisionStage *>::iterator stage=collisionStages.begin();
>> 508
>> 509 for(; stage != collisionStages.end(); stage++)
>> 510 (*stage)->DoCollisionStep(this,aTrack, aStep);
>> 511
>> 512 if(registerDepositedEnergy) {
>> 513 pParticleChange->ProposeLocalEnergyDeposit(IonizingLoss+NIEL);
>> 514 pParticleChange->ProposeNonIonizingEnergyDeposit(NIEL);
>> 515 //MHM G4cout << "depositing energy, total = " << IonizingLoss+NIEL << " NIEL = " << NIEL << G4endl;
>> 516 }
524 517
525 // find out what we hit, and record it in ou << 518 return G4VDiscreteProcess::PostStepDoIt( aTrack, aStep );
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 } <<
557 <<
558 G4ScreenedCoulombClassicalKinematics::G4Screen <<
559 : // instantiate all the needed functions s <<
560 // done at run time <<
561 // we will be solving x^2 - x phi(x*au)/e <<
562 // or, for easier scaling, x'^2 - x' au p <<
563 // note that only the last of these gets <<
564 phifunc(c2.const_plugin_function()), <<
565 xovereps(c2.linear(0., 0., 0.)), <<
566 // will fill this in with the right slope <<
567 diff(c2.quadratic(0., 0., 0., 1.) - xovere <<
568 {} <<
569 <<
570 G4bool G4ScreenedCoulombClassicalKinematics::D <<
571 <<
572 <<
573 { <<
574 G4double au = screen->au; <<
575 G4CoulombKinematicsInfo& kin = master->GetKi <<
576 G4double A = kin.a2; <<
577 G4double a1 = kin.a1; <<
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 <<
592 } <<
593 <<
594 // we will be solving x^2 - x phi(x*au)/eps <<
595 // or, for easier scaling, x'^2 - x' au phi( <<
596 xovereps.reset(0., 0.0, au / eps); // slope <<
597 phifunc.set_function(&(screen->EMphiData.get <<
598 // install interpolating table <<
599 G4double xx1, phip, phip2; <<
600 G4int root_error; <<
601 xx1 = diff->find_root(phifunc.xmin(), std::m <<
602 std::min(xx0 * au, phi <<
603 &phip, &phip2) <<
604 / au; <<
605 <<
606 if (root_error) { <<
607 G4cout << "Screened Coulomb Root Finder Er <<
608 G4cout << "au " << au << " A " << A << " a <<
609 << " beta " << beta << G4endl; <<
610 G4cout << " xmin " << phifunc.xmin() << " <<
611 G4cout << " f(xmin) " << phifunc(phifunc.x <<
612 << phifunc(std::min(10 * xx0 * au, <<
613 G4cout << " xstart " << std::min(xx0 * au, <<
614 << beta * beta * au * au; <<
615 G4cout << G4endl; <<
616 throw c2_exception("Failed root find"); <<
617 } <<
618 <<
619 // phiprime is scaled by one factor of au be <<
620 // at (xx0*au), <<
621 G4double phiprime = phip * au; <<
622 <<
623 // lambda0 is from W&M 19 <<
624 G4double lambda0 = <<
625 1.0 / std::sqrt(0.5 + beta * beta / (2.0 * <<
626 <<
627 // compute the 6-term Lobatto integral alpha <<
628 // different coefficients) <<
629 // this is probably completely un-needed but <<
630 // quality results, <<
631 G4double alpha = (1.0 + lambda0) / 30.0; <<
632 G4double xvals[] = {0.98302349, 0.84652241, <<
633 G4double weights[] = {0.03472124, 0.14769029 <<
634 for (G4int k = 0; k < 4; k++) { <<
635 G4double x, ff; <<
636 x = xx1 / xvals[k]; <<
637 ff = 1.0 / std::sqrt(1.0 - phifunc(x * au) <<
638 alpha += weights[k] * ff; <<
639 } <<
640 <<
641 phifunc.unset_function(); <<
642 // throws an exception if used without setti <<
643 <<
644 G4double thetac1 = pi * beta * alpha / xx1; <<
645 // complement of CM scattering angle <<
646 G4double sintheta = std::sin(thetac1); // n <<
647 G4double costheta = -std::cos(thetac1); // <<
648 // G4double psi=std::atan2(sintheta, costhet <<
649 // lab scattering angle (M&T 3rd eq. 8.69) <<
650 <<
651 // numerics note: because we checked above <<
652 // of beta which give real recoils, <<
653 // we don't have to look too closely for the <<
654 // (which would cause sin(theta) <<
655 // and 1-cos(theta) to both vanish and make <<
656 G4double zeta = std::atan2(sintheta, 1 - cos <<
657 // lab recoil angle (M&T 3rd eq. 8.73) <<
658 G4double coszeta = std::cos(zeta); <<
659 G4double sinzeta = std::sin(zeta); <<
660 <<
661 kin.sinTheta = sintheta; <<
662 kin.cosTheta = costheta; <<
663 kin.sinZeta = sinzeta; <<
664 kin.cosZeta = coszeta; <<
665 return 1; // all OK, collision is valid <<
666 } 519 }
667 520
668 void G4ScreenedCoulombClassicalKinematics::DoC << 521 G4ScreenedCoulombClassicalKinematics::G4ScreenedCoulombClassicalKinematics() :
669 << 522 // instantiate all the needed functions statically, so no allocation is done at run time
>> 523 // we will be solving x^2 - x phi(x*au)/eps - beta^2 == 0.0
>> 524 // or, for easier scaling, x'^2 - x' au phi(x')/eps - beta^2 au^2
>> 525 // note that only the last of these gets deleted, since it owns the rest
>> 526 phifunc(c2.const_plugin_function()),
>> 527 xovereps(c2.linear(0., 0., 0.)), // will fill this in with the right slope at run time
>> 528 diff(c2.quadratic(0., 0., 0., 1.)-xovereps*phifunc)
670 { 529 {
671 if (!master->GetValidCollision()) return; <<
672 <<
673 G4ParticleChange& aParticleChange = master-> <<
674 G4CoulombKinematicsInfo& kin = master->GetKi <<
675 <<
676 const G4DynamicParticle* incidentParticle = <<
677 G4ParticleDefinition* baseParticle = aTrack. <<
678 <<
679 G4double incidentEnergy = incidentParticle-> <<
680 <<
681 // this adjustment to a1 gives the right res <<
682 // (constant gamma) <<
683 // relativistic collisions. Hard collisions <<
684 // Coulombic and hadronic terms interfere an <<
685 G4double gamma = (1.0 + incidentEnergy / bas <<
686 G4double a1 = kin.a1 * gamma; // relativist <<
687 <<
688 G4ParticleDefinition* recoilIon = kin.recoil <<
689 G4double A = recoilIon->GetPDGMass() / amu_c <<
690 G4int Z = (G4int)((recoilIon->GetPDGCharge() <<
691 <<
692 G4double Ec = incidentEnergy * (A / (A + a1) <<
693 // energy in CM frame (non-relativistic!) <<
694 const G4ScreeningTables* screen = kin.crossS <<
695 G4double au = screen->au; // screening leng <<
696 <<
697 G4double beta = kin.impactParameter / au; <<
698 // dimensionless impact parameter <<
699 G4double eps = Ec / (screen->z1 * Z * elm_co <<
700 // dimensionless energy <<
701 <<
702 G4bool ok = DoScreeningComputation(master, s <<
703 if (!ok) { <<
704 master->SetValidCollision(0); // flag bad <<
705 return; // just bail out without setting <<
706 } <<
707 <<
708 G4double eRecoil = <<
709 4 * incidentEnergy * a1 * A * kin.cosZeta <<
710 kin.eRecoil = eRecoil; <<
711 <<
712 if (incidentEnergy - eRecoil < master->GetRe <<
713 aParticleChange.ProposeEnergy(0.0); <<
714 master->DepositEnergy(int(screen->z1), a1, <<
715 } <<
716 <<
717 if (master->GetEnableRecoils() && eRecoil > <<
718 kin.recoilIon = recoilIon; <<
719 } <<
720 else { <<
721 kin.recoilIon = 0; // this flags no recoi <<
722 master->DepositEnergy(Z, A, kin.targetMate <<
723 } <<
724 } 530 }
725 531
726 void G4SingleScatter::DoCollisionStep(G4Screen << 532 G4bool G4ScreenedCoulombClassicalKinematics::DoScreeningComputation(G4ScreenedNuclearRecoil *master,
727 const G4 << 533 const G4ScreeningTables *screen, G4double eps, G4double beta)
728 { << 534 {
729 if (!master->GetValidCollision()) return; << 535 G4double au=screen->au;
730 << 536 G4CoulombKinematicsInfo &kin=master->GetKinematics();
731 G4CoulombKinematicsInfo& kin = master->GetKi << 537 G4double A=kin.a2;
732 G4ParticleChange& aParticleChange = master-> << 538 G4double a1=kin.a1;
>> 539
>> 540 G4double xx0; // first estimate of closest approach
>> 541 if(eps < 5.0) {
>> 542 G4double y=std::log(eps);
>> 543 G4double mlrho4=((((3.517e-4*y+1.401e-2)*y+2.393e-1)*y+2.734)*y+2.220);
>> 544 G4double rho4=std::exp(-mlrho4); // W&M eq. 18
>> 545 G4double bb2=0.5*beta*beta;
>> 546 xx0=std::sqrt(bb2+std::sqrt(bb2*bb2+rho4)); // W&M eq. 17
>> 547 } else {
>> 548 G4double ee=1.0/(2.0*eps);
>> 549 xx0=ee+std::sqrt(ee*ee+beta*beta); // W&M eq. 15 (Rutherford value)
>> 550 if(master->CheckNuclearCollision(A, a1, xx0*au)) return 0; // nuclei too close
>> 551
>> 552 }
>> 553
>> 554 // we will be solving x^2 - x phi(x*au)/eps - beta^2 == 0.0
>> 555 // or, for easier scaling, x'^2 - x' au phi(x')/eps - beta^2 au^2
>> 556 xovereps.reset(0., 0.0, au/eps); // slope of x*au/eps term
>> 557 phifunc.set_function(&(screen->EMphiData.get())); // install interpolating table
>> 558 G4double xx1, phip, phip2;
>> 559 G4int root_error;
>> 560 xx1=diff->find_root(phifunc.xmin(), std::min(10*xx0*au,phifunc.xmax()),
>> 561 std::min(xx0*au, phifunc.xmax()), beta*beta*au*au, &root_error, &phip, &phip2)/au;
>> 562
>> 563 if(root_error) {
>> 564 G4cout << "Screened Coulomb Root Finder Error" << G4endl;
>> 565 G4cout << "au " << au << " A " << A << " a1 " << a1 << " xx1 " << xx1 << " eps " << eps << " beta " << beta << G4endl;
>> 566 G4cout << " xmin " << phifunc.xmin() << " xmax " << std::min(10*xx0*au,phifunc.xmax()) ;
>> 567 G4cout << " f(xmin) " << phifunc(phifunc.xmin()) << " f(xmax) " << phifunc(std::min(10*xx0*au,phifunc.xmax())) ;
>> 568 G4cout << " xstart " << std::min(xx0*au, phifunc.xmax()) << " target " << beta*beta*au*au ;
>> 569 G4cout << G4endl;
>> 570 throw c2_exception("Failed root find");
>> 571 }
>> 572
>> 573 // phiprime is scaled by one factor of au because phi is evaluated at (xx0*au),
>> 574 G4double phiprime=phip*au;
>> 575
>> 576 //lambda0 is from W&M 19
>> 577 G4double lambda0=1.0/std::sqrt(0.5+beta*beta/(2.0*xx1*xx1)-phiprime/(2.0*eps));
>> 578
>> 579 //compute the 6-term Lobatto integral alpha (per W&M 21, with different coefficients)
>> 580 // this is probably completely un-needed but gives the highest quality results,
>> 581 G4double alpha=(1.0+ lambda0)/30.0;
>> 582 G4double xvals[]={0.98302349, 0.84652241, 0.53235309, 0.18347974};
>> 583 G4double weights[]={0.03472124, 0.14769029, 0.23485003, 0.18602489};
>> 584 for(G4int k=0; k<4; k++) {
>> 585 G4double x, ff;
>> 586 x=xx1/xvals[k];
>> 587 ff=1.0/std::sqrt(1.0-phifunc(x*au)/(x*eps)-beta*beta/(x*x));
>> 588 alpha+=weights[k]*ff;
>> 589 }
>> 590
>> 591 phifunc.unset_function(); // throws an exception if used without setting again
733 592
734 const G4DynamicParticle* incidentParticle = << 593 G4double thetac1=CLHEP::pi*beta*alpha/xx1; // complement of CM scattering angle
735 G4double incidentEnergy = incidentParticle-> << 594 G4double sintheta=std::sin(thetac1); //note sin(pi-theta)=sin(theta)
736 G4double eRecoil = kin.eRecoil; << 595 G4double costheta=-std::cos(thetac1); // note cos(pi-theta)=-cos(theta)
737 << 596 // G4double psi=std::atan2(sintheta, costheta+a1/A); // lab scattering angle (M&T 3rd eq. 8.69)
738 G4double azimuth = G4UniformRand() * (2.0 * << 597
739 G4double sa = std::sin(azimuth); << 598 // numerics note: because we checked above for reasonable values of beta which give real recoils,
740 G4double ca = std::cos(azimuth); << 599 // we don't have to look too closely for theta -> 0 here (which would cause sin(theta)
741 << 600 // and 1-cos(theta) to both vanish and make the atan2 ill behaved).
742 G4ThreeVector recoilMomentumDirection(kin.si << 601 G4double zeta=std::atan2(sintheta, 1-costheta); // lab recoil angle (M&T 3rd eq. 8.73)
743 G4ParticleMomentum incidentDirection = incid << 602 G4double coszeta=std::cos(zeta);
744 recoilMomentumDirection = recoilMomentumDire << 603 G4double sinzeta=std::sin(zeta);
745 G4ThreeVector recoilMomentum = << 604
746 recoilMomentumDirection * std::sqrt(2.0 * << 605 kin.sinTheta=sintheta;
747 << 606 kin.cosTheta=costheta;
748 if (aParticleChange.GetEnergy() != 0.0) { << 607 kin.sinZeta=sinzeta;
749 // DoKinematics hasn't stopped it! << 608 kin.cosZeta=coszeta;
750 G4ThreeVector beamMomentum = incidentParti << 609 return 1; // all OK, collision is valid
751 aParticleChange.ProposeMomentumDirection(b << 610 }
752 aParticleChange.ProposeEnergy(incidentEner << 611
753 } << 612 void G4ScreenedCoulombClassicalKinematics::DoCollisionStep(G4ScreenedNuclearRecoil *master,
754 << 613 const G4Track& aTrack, const G4Step&) {
755 if (kin.recoilIon) { << 614
756 G4DynamicParticle* recoil = << 615 if(!master->GetValidCollision()) return;
757 new G4DynamicParticle(kin.recoilIon, rec << 616
758 << 617 G4ParticleChange &aParticleChange=master->GetParticleChange();
759 aParticleChange.SetNumberOfSecondaries(1); << 618 G4CoulombKinematicsInfo &kin=master->GetKinematics();
760 aParticleChange.AddSecondary(recoil); << 619
761 } << 620 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
>> 621 G4ParticleDefinition *baseParticle=aTrack.GetDefinition();
>> 622
>> 623 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
>> 624
>> 625 // this adjustment to a1 gives the right results for soft (constant gamma)
>> 626 // relativistic collisions. Hard collisions are wrong anyway, since the
>> 627 // Coulombic and hadronic terms interfere and cannot be added.
>> 628 G4double gamma=(1.0+incidentEnergy/baseParticle->GetPDGMass());
>> 629 G4double a1=kin.a1*gamma; // relativistic gamma correction
>> 630
>> 631 G4ParticleDefinition *recoilIon=kin.recoilIon;
>> 632 G4double A=recoilIon->GetPDGMass()/amu_c2;
>> 633 G4int Z=(G4int)((recoilIon->GetPDGCharge()/eplus)+0.5);
>> 634
>> 635 G4double Ec = incidentEnergy*(A/(A+a1)); // energy in CM frame (non-relativistic!)
>> 636 const G4ScreeningTables *screen=kin.crossSection->GetScreening(Z);
>> 637 G4double au=screen->au; // screening length
>> 638
>> 639 G4double beta = kin.impactParameter/au; // dimensionless impact parameter
>> 640 G4double eps = Ec/(screen->z1*Z*elm_coupling/au); // dimensionless energy
>> 641
>> 642 G4bool ok=DoScreeningComputation(master, screen, eps, beta);
>> 643 if(!ok) {
>> 644 master->SetValidCollision(0); // flag bad collision
>> 645 return; // just bail out without setting valid flag
>> 646 }
>> 647
>> 648 G4double eRecoil=4*incidentEnergy*a1*A*kin.cosZeta*kin.cosZeta/((a1+A)*(a1+A));
>> 649 kin.eRecoil=eRecoil;
>> 650
>> 651 if(incidentEnergy-eRecoil < master->GetRecoilCutoff()*a1) {
>> 652 aParticleChange.ProposeEnergy(0.0);
>> 653 master->DepositEnergy(int(screen->z1), a1, kin.targetMaterial, incidentEnergy-eRecoil);
>> 654 }
>> 655
>> 656 if(master->GetEnableRecoils() && eRecoil > master->GetRecoilCutoff() * kin.a2) {
>> 657 kin.recoilIon=recoilIon;
>> 658 } else {
>> 659 kin.recoilIon=0; // this flags no recoil to be generated
>> 660 master->DepositEnergy(Z, A, kin.targetMaterial, eRecoil) ;
>> 661 }
>> 662 }
>> 663
>> 664 void G4SingleScatter::DoCollisionStep(G4ScreenedNuclearRecoil *master,
>> 665 const G4Track& aTrack, const G4Step&) {
>> 666
>> 667 if(!master->GetValidCollision()) return;
>> 668
>> 669 G4CoulombKinematicsInfo &kin=master->GetKinematics();
>> 670 G4ParticleChange &aParticleChange=master->GetParticleChange();
>> 671
>> 672 const G4DynamicParticle* incidentParticle = aTrack.GetDynamicParticle();
>> 673 G4double incidentEnergy = incidentParticle->GetKineticEnergy();
>> 674 G4double eRecoil=kin.eRecoil;
>> 675
>> 676 G4double azimuth=G4UniformRand()*(2.0*CLHEP::pi);
>> 677 G4double sa=std::sin(azimuth);
>> 678 G4double ca=std::cos(azimuth);
>> 679
>> 680 G4ThreeVector recoilMomentumDirection(kin.sinZeta*ca, kin.sinZeta*sa, kin.cosZeta);
>> 681 G4ParticleMomentum incidentDirection = incidentParticle->GetMomentumDirection();
>> 682 recoilMomentumDirection=recoilMomentumDirection.rotateUz(incidentDirection);
>> 683 G4ThreeVector recoilMomentum=recoilMomentumDirection*std::sqrt(2.0*eRecoil*kin.a2*amu_c2);
>> 684
>> 685 if(aParticleChange.GetEnergy() != 0.0) { // DoKinematics hasn't stopped it!
>> 686 G4ThreeVector beamMomentum=incidentParticle->GetMomentum()-recoilMomentum;
>> 687 aParticleChange.ProposeMomentumDirection(beamMomentum.unit()) ;
>> 688 aParticleChange.ProposeEnergy(incidentEnergy-eRecoil);
>> 689 }
>> 690
>> 691 if(kin.recoilIon) {
>> 692 G4DynamicParticle* recoil = new G4DynamicParticle (kin.recoilIon,
>> 693 recoilMomentumDirection,eRecoil) ;
>> 694
>> 695 aParticleChange.SetNumberOfSecondaries(1);
>> 696 aParticleChange.AddSecondary(recoil);
>> 697 }
762 } 698 }
763 699
764 G4bool G4ScreenedNuclearRecoil::IsApplicable(c << 700 G4bool G4ScreenedNuclearRecoil::
>> 701 IsApplicable(const G4ParticleDefinition& aParticleType)
765 { 702 {
766 return aParticleType == *(G4Proton::Proton() << 703 return aParticleType == *(G4Proton::Proton()) ||
767 || aParticleType.GetParticleType() == << 704 aParticleType.GetParticleType() == "nucleus" ||
>> 705 aParticleType.GetParticleType() == "static_nucleus";
768 } 706 }
769 707
770 void G4ScreenedNuclearRecoil::BuildPhysicsTabl << 708
>> 709 void
>> 710 G4ScreenedNuclearRecoil::
>> 711 DumpPhysicsTable(const G4ParticleDefinition&)
771 { 712 {
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 } 713 }
781 714
782 void G4ScreenedNuclearRecoil::DumpPhysicsTable <<
783 <<
784 // This used to be the file mhmScreenedNuclear 715 // This used to be the file mhmScreenedNuclearRecoil_native.cc
785 // it has been included here to collect this f << 716 // it has been included here to collect this file into a smaller number of packages
786 // number of packages <<
787 717
788 #include "G4DataVector.hh" 718 #include "G4DataVector.hh"
>> 719 #include "G4Material.hh"
789 #include "G4Element.hh" 720 #include "G4Element.hh"
790 #include "G4ElementVector.hh" <<
791 #include "G4Isotope.hh" 721 #include "G4Isotope.hh"
792 #include "G4Material.hh" <<
793 #include "G4MaterialCutsCouple.hh" 722 #include "G4MaterialCutsCouple.hh"
794 << 723 #include "G4ElementVector.hh"
795 #include <vector> 724 #include <vector>
796 725
797 G4_c2_function& ZBLScreening(G4int z1, G4int z << 726 G4_c2_function &ZBLScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
798 { <<
799 static const size_t ncoef = 4; <<
800 static G4double scales[ncoef] = {-3.2, -0.94 <<
801 static G4double coefs[ncoef] = {0.1818, 0.50 <<
802 <<
803 G4double au = 0.8854 * angstrom * 0.529 / (s <<
804 std::vector<G4double> r(npoints), phi(npoint <<
805 <<
806 for (size_t i = 0; i < npoints; i++) { <<
807 G4double rr = (float)i / (float)(npoints - <<
808 r[i] = rr * rr * rMax; <<
809 // use quadratic r scale to make sampling <<
810 G4double sum = 0.0; <<
811 for (size_t j = 0; j < ncoef; j++) <<
812 sum += coefs[j] * std::exp(scales[j] * r <<
813 phi[i] = sum; <<
814 } <<
815 <<
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 { 727 {
828 static const size_t ncoef = 3; << 728 static const size_t ncoef=4;
829 static G4double scales[ncoef] = {-6.0, -1.2, << 729 static G4double scales[ncoef]={-3.2, -0.9432, -0.4028, -0.2016};
830 static G4double coefs[ncoef] = {0.10, 0.55, << 730 static G4double coefs[ncoef]={0.1818,0.5099,0.2802,0.0281};
831 << 731
832 G4double au = 0.8853 * 0.529 * angstrom / st << 732 G4double au=0.8854*angstrom*0.529/(std::pow(z1, 0.23)+std::pow(z2,0.23));
833 std::vector<G4double> r(npoints), phi(npoint << 733 std::vector<G4double> r(npoints), phi(npoints);
834 << 734
835 for (size_t i = 0; i < npoints; i++) { << 735 for(size_t i=0; i<npoints; i++) {
836 G4double rr = (float)i / (float)(npoints - << 736 G4double rr=(float)i/(float)(npoints-1);
837 r[i] = rr * rr * rMax; << 737 r[i]=rr*rr*rMax; // use quadratic r scale to make sampling fine near the center
838 // use quadratic r scale to make sampling << 738 G4double sum=0.0;
839 G4double sum = 0.0; << 739 for(size_t j=0; j<ncoef; j++) sum+=coefs[j]*std::exp(scales[j]*r[i]/au);
840 for (size_t j = 0; j < ncoef; j++) << 740 phi[i]=sum;
841 sum += coefs[j] * std::exp(scales[j] * r << 741 }
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 <<
909 G4NativeScreenedCoulombCrossSection::~G4Native <<
910 <<
911 G4NativeScreenedCoulombCrossSection::G4NativeS <<
912 { <<
913 AddScreeningFunction("zbl", ZBLScreening); <<
914 AddScreeningFunction("lj", LJScreening); <<
915 AddScreeningFunction("mol", MoliereScreening <<
916 AddScreeningFunction("ljzbl", LJZBLScreening <<
917 } <<
918 <<
919 std::vector<G4String> G4NativeScreenedCoulombC <<
920 { <<
921 std::vector<G4String> keys; <<
922 // find the available screening keys <<
923 std::map<std::string, ScreeningFunc>::const_ <<
924 for (; sfunciter != phiMap.end(); sfunciter+ <<
925 keys.push_back((*sfunciter).first); <<
926 return keys; <<
927 } <<
928 <<
929 static inline G4double cm_energy(G4double a1, <<
930 { <<
931 // "relativistically correct energy in CM fr <<
932 G4double m1 = a1 * amu_c2, mass2 = a2 * amu_ <<
933 G4double mc2 = (m1 + mass2); <<
934 G4double f = 2.0 * mass2 * t0 / (mc2 * mc2); <<
935 // old way: return (f < 1e-6) ? 0.5*mc2*f : <<
936 // formally equivalent to previous, but nume <<
937 // f without conditional <<
938 // uses identity (sqrt(1+x) - 1)(sqrt(1+x) + <<
939 return mc2 * f / (std::sqrt(1.0 + f) + 1.0); <<
940 } <<
941 <<
942 static inline G4double thetac(G4double m1, G4d <<
943 { <<
944 G4double s2th2 = eratio * ((m1 + mass2) * (m <<
945 G4double sth2 = std::sqrt(s2th2); <<
946 return 2.0 * std::asin(sth2); <<
947 } <<
948 742
949 void G4NativeScreenedCoulombCrossSection::Load << 743 // compute the derivative at the origin for the spline
950 << 744 G4double phiprime0=0.0;
951 { << 745 for(size_t j=0; j<ncoef; j++) phiprime0+=scales[j]*coefs[j]*std::exp(scales[j]*r[0]/au);
952 static const size_t sigLen = 200; << 746 phiprime0*=(1.0/au); // put back in natural units;
953 // since sigma doesn't matter much, a very c << 747
954 G4DataVector energies(sigLen); << 748 *auval=au;
955 G4DataVector data(sigLen); << 749 return c2.lin_log_interpolating_function().load(r, phi, false, phiprime0,true,0);
956 << 750 }
957 a1 = standardmass(z1); << 751
958 // use standardized values for mass for buil << 752 G4_c2_function &MoliereScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
959 << 753 {
960 const G4MaterialTable* materialTable = G4Mat << 754 static const size_t ncoef=3;
961 G4int nMaterials = G4Material::GetNumberOfMa << 755 static G4double scales[ncoef]={-6.0, -1.2, -0.3};
962 << 756 static G4double coefs[ncoef]={0.10, 0.55, 0.35};
963 for (G4int im = 0; im < nMaterials; im++) { << 757
964 const G4Material* material = (*materialTab << 758 G4double au=0.8853*0.529*angstrom/std::sqrt(std::pow(z1, 0.6667)+std::pow(z2,0.6667));
965 const G4ElementVector* elementVector = mat << 759 std::vector<G4double> r(npoints), phi(npoints);
966 const G4int nMatElements = material->GetNu << 760
967 << 761 for(size_t i=0; i<npoints; i++) {
968 for (G4int iEl = 0; iEl < nMatElements; iE << 762 G4double rr=(float)i/(float)(npoints-1);
969 const G4Element* element = (*elementVect << 763 r[i]=rr*rr*rMax; // use quadratic r scale to make sampling fine near the center
970 G4int Z = element->GetZasInt(); << 764 G4double sum=0.0;
971 G4double a2 = element->GetA() * (mole / << 765 for(size_t j=0; j<ncoef; j++) sum+=coefs[j]*std::exp(scales[j]*r[i]/au);
972 << 766 phi[i]=sum;
973 if (sigmaMap.find(Z) != sigmaMap.end()) <<
974 // we've already got this element <<
975 <<
976 // find the screening function generator <<
977 std::map<std::string, ScreeningFunc>::it <<
978 if (sfunciter == phiMap.end()) { <<
979 G4ExceptionDescription ed; <<
980 ed << "No such screening key <" << scr <<
981 G4Exception("G4NativeScreenedCoulombCr <<
982 } <<
983 ScreeningFunc sfunc = (*sfunciter).secon <<
984 <<
985 G4double au; <<
986 G4_c2_ptr screen = sfunc(z1, Z, 200, 50. <<
987 // generate the screening data <<
988 G4ScreeningTables st; <<
989 <<
990 st.EMphiData = screen; // save our phi <<
991 st.z1 = z1; <<
992 st.m1 = a1; <<
993 st.z2 = Z; <<
994 st.m2 = a2; <<
995 st.emin = recoilCutoff; <<
996 st.au = au; <<
997 <<
998 // now comes the hard part... build the <<
999 // tables from the phi table <<
1000 // based on (pi-thetac) = pi*beta*alpha <<
1001 // alpha is very nearly unity, always <<
1002 // so just solve it wth alpha=1, which <<
1003 // much easier <<
1004 // this function returns an approximati <<
1005 // (beta/x0)^2=phi(x0)/(eps*x0)-1 ~ ((p <<
1006 // Since we don't need exact sigma valu <<
1007 // (within a factor of 2 almost always) <<
1008 // this rearranges to phi(x0)/(x0*eps) <<
1009 // 2*theta/pi - theta^2/pi^2 <<
1010 <<
1011 c2_linear_p<G4double>& c2eps = c2.linea <<
1012 // will store an appropriate eps inside <<
1013 G4_c2_ptr phiau = screen(c2.linear(0.0, <<
1014 G4_c2_ptr x0func(phiau / c2eps); <<
1015 // this will be phi(x)/(x*eps) when c2e <<
1016 x0func->set_domain(1e-6 * angstrom / au <<
1017 // needed for inverse function <<
1018 // use the c2_inverse_function interfac <<
1019 // it is more efficient for an ordered <<
1020 // computation of values. <<
1021 G4_c2_ptr x0_solution(c2.inverse_functi <<
1022 <<
1023 G4double m1c2 = a1 * amu_c2; <<
1024 G4double escale = z1 * Z * elm_coupling <<
1025 // energy at screening distance <<
1026 G4double emax = m1c2; <<
1027 // model is doubtful in very relativist <<
1028 G4double eratkin = 0.9999 * (4 * a1 * a <<
1029 // #maximum kinematic ratio possible at <<
1030 G4double cmfact0 = st.emin / cm_energy( <<
1031 G4double l1 = std::log(emax); <<
1032 G4double l0 = std::log(st.emin * cmfact <<
1033 <<
1034 if (verbosity >= 1) <<
1035 G4cout << "Native Screening: " << scr <<
1036 << a2 << " " << recoilCutoff < <<
1037 <<
1038 for (size_t idx = 0; idx < sigLen; idx+ <<
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 } 767 }
1064 catch (c2_exception&) { << 768
1065 G4Exception("G4ScreenedNuclearRecoi << 769 // compute the derivative at the origin for the spline
1066 "failure in inverse sol << 770 G4double phiprime0=0.0;
>> 771 for(size_t j=0; j<ncoef; j++) phiprime0+=scales[j]*coefs[j]*std::exp(scales[j]*r[0]/au);
>> 772 phiprime0*=(1.0/au); // put back in natural units;
>> 773
>> 774 *auval=au;
>> 775 return c2.lin_log_interpolating_function().load(r, phi, false, phiprime0,true,0);
>> 776 }
>> 777
>> 778 G4_c2_function &LJScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
>> 779 {
>> 780 //from Loftager, Besenbacher, Jensen & Sorensen
>> 781 //PhysRev A20, 1443++, 1979
>> 782 G4double au=0.8853*0.529*angstrom/std::sqrt(std::pow(z1, 0.6667)+std::pow(z2,0.6667));
>> 783 std::vector<G4double> r(npoints), phi(npoints);
>> 784
>> 785 for(size_t i=0; i<npoints; i++) {
>> 786 G4double rr=(float)i/(float)(npoints-1);
>> 787 r[i]=rr*rr*rMax; // use quadratic r scale to make sampling fine near the center
>> 788
>> 789 G4double y=std::sqrt(9.67*r[i]/au);
>> 790 G4double ysq=y*y;
>> 791 G4double phipoly=1+y+0.3344*ysq+0.0485*y*ysq+0.002647*ysq*ysq;
>> 792 phi[i]=phipoly*std::exp(-y);
>> 793 // G4cout << r[i] << " " << phi[i] << G4endl;
>> 794 }
>> 795
>> 796 // compute the derivative at the origin for the spline
>> 797 G4double logphiprime0=(9.67/2.0)*(2*0.3344-1.0); // #avoid 0/0 on first element
>> 798 logphiprime0 *= (1.0/au); // #put back in natural units
>> 799
>> 800 *auval=au;
>> 801 return c2.lin_log_interpolating_function().load(r, phi, false, logphiprime0*phi[0],true,0);
>> 802 }
>> 803
>> 804 G4_c2_function &LJZBLScreening(G4int z1, G4int z2, size_t npoints, G4double rMax, G4double *auval)
>> 805 {
>> 806 // hybrid of LJ and ZBL, uses LJ if x < 0.25*auniv, ZBL if x > 1.5*auniv, and
>> 807 /// connector in between. These numbers are selected so the switchover
>> 808 // is very near the point where the functions naturally cross.
>> 809 G4double auzbl, aulj;
>> 810
>> 811 c2p zbl=ZBLScreening(z1, z2, npoints, rMax, &auzbl);
>> 812 c2p lj=LJScreening(z1, z2, npoints, rMax, &aulj);
>> 813
>> 814 G4double au=(auzbl+aulj)*0.5;
>> 815 lj->set_domain(lj->xmin(), 0.25*au);
>> 816 zbl->set_domain(1.5*au,zbl->xmax());
>> 817
>> 818 c2p conn=c2.connector_function(lj->xmax(), lj, zbl->xmin(), zbl, true,0);
>> 819 c2_piecewise_function_p<G4double> &pw=c2.piecewise_function();
>> 820 c2p keepit(pw);
>> 821 pw.append_function(lj);
>> 822 pw.append_function(conn);
>> 823 pw.append_function(zbl);
>> 824
>> 825 *auval=au;
>> 826 keepit.release_for_return();
>> 827 return pw;
>> 828 }
>> 829
>> 830 G4NativeScreenedCoulombCrossSection::~G4NativeScreenedCoulombCrossSection() {
>> 831 }
>> 832
>> 833 G4NativeScreenedCoulombCrossSection::G4NativeScreenedCoulombCrossSection() {
>> 834 AddScreeningFunction("zbl", ZBLScreening);
>> 835 AddScreeningFunction("lj", LJScreening);
>> 836 AddScreeningFunction("mol", MoliereScreening);
>> 837 AddScreeningFunction("ljzbl", LJZBLScreening);
>> 838 }
>> 839
>> 840 std::vector<G4String> G4NativeScreenedCoulombCrossSection::GetScreeningKeys() const {
>> 841 std::vector<G4String> keys;
>> 842 // find the available screening keys
>> 843 std::map<std::string, ScreeningFunc>::const_iterator sfunciter=phiMap.begin();
>> 844 for(; sfunciter != phiMap.end(); sfunciter++) keys.push_back((*sfunciter).first);
>> 845 return keys;
>> 846 }
>> 847
>> 848 static inline G4double cm_energy(G4double a1, G4double a2, G4double t0) {
>> 849 // "relativistically correct energy in CM frame"
>> 850 G4double m1=a1*amu_c2, mass2=a2*amu_c2;
>> 851 G4double mc2=(m1+mass2);
>> 852 G4double f=2.0*mass2*t0/(mc2*mc2);
>> 853 // old way: return (f < 1e-6) ? 0.5*mc2*f : mc2*(std::sqrt(1.0+f)-1.0);
>> 854 // formally equivalent to previous, but numerically stable for all f without conditional
>> 855 // uses identity (sqrt(1+x) - 1)(sqrt(1+x) + 1) = x
>> 856 return mc2*f/(std::sqrt(1.0+f)+1.0);
>> 857 }
>> 858
>> 859 static inline G4double thetac(G4double m1, G4double mass2, G4double eratio) {
>> 860 G4double s2th2=eratio*( (m1+mass2)*(m1+mass2)/(4.0*m1*mass2) );
>> 861 G4double sth2=std::sqrt(s2th2);
>> 862 return 2.0*std::asin(sth2);
>> 863 }
>> 864
>> 865 void G4NativeScreenedCoulombCrossSection::LoadData(G4String screeningKey, G4int z1, G4double a1, G4double recoilCutoff)
>> 866 {
>> 867 static const size_t sigLen=200; // since sigma doesn't matter much, a very coarse table will do
>> 868 G4DataVector energies(sigLen);
>> 869 G4DataVector data(sigLen);
>> 870
>> 871 a1=standardmass(z1); // use standardized values for mass for building tables
>> 872
>> 873 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
>> 874 if (materialTable == 0) { return; }
>> 875 //G4Exception("mhmNativeCrossSection::LoadData - no MaterialTable found)");
>> 876
>> 877 G4int nMaterials = G4Material::GetNumberOfMaterials();
>> 878
>> 879 for (G4int im=0; im<nMaterials; im++)
>> 880 {
>> 881 const G4Material* material= (*materialTable)[im];
>> 882 const G4ElementVector* elementVector = material->GetElementVector();
>> 883 const G4int nMatElements = material->GetNumberOfElements();
>> 884
>> 885 for (G4int iEl=0; iEl<nMatElements; iEl++)
>> 886 {
>> 887 G4Element* element = (*elementVector)[iEl];
>> 888 G4int Z = (G4int) element->GetZ();
>> 889 G4double a2=element->GetA()*(mole/gram);
>> 890
>> 891 if(sigmaMap.find(Z)!=sigmaMap.end()) continue; // we've already got this element
>> 892
>> 893 // find the screening function generator we need
>> 894 std::map<std::string, ScreeningFunc>::iterator sfunciter=phiMap.find(screeningKey);
>> 895 if(sfunciter==phiMap.end()) {
>> 896 G4cout << "no such screening key " << screeningKey << G4endl; // FIXME later
>> 897 exit(1);
>> 898 }
>> 899 ScreeningFunc sfunc=(*sfunciter).second;
>> 900
>> 901 G4double au;
>> 902 G4_c2_ptr screen=sfunc(z1, Z, 200, 50.0*angstrom, &au); // generate the screening data
>> 903 G4ScreeningTables st;
>> 904
>> 905 st.EMphiData=screen; //save our phi table
>> 906 st.z1=z1; st.m1=a1; st.z2=Z; st.m2=a2; st.emin=recoilCutoff;
>> 907 st.au=au;
>> 908
>> 909 // now comes the hard part... build the total cross section tables from the phi table
>> 910 //based on (pi-thetac) = pi*beta*alpha/x0, but noting that alpha is very nearly unity, always
>> 911 //so just solve it wth alpha=1, which makes the solution much easier
>> 912 //this function returns an approximation to (beta/x0)^2=phi(x0)/(eps*x0)-1 ~ ((pi-thetac)/pi)^2
>> 913 //Since we don't need exact sigma values, this is good enough (within a factor of 2 almost always)
>> 914 //this rearranges to phi(x0)/(x0*eps) = 2*theta/pi - theta^2/pi^2
>> 915
>> 916 c2_linear_p<G4double> &c2eps=c2.linear(0.0, 0.0, 1.0); // will store an appropriate eps inside this in loop
>> 917 G4_c2_ptr phiau=screen(c2.linear(0.0, 0.0, au));
>> 918 G4_c2_ptr x0func(phiau/c2eps); // this will be phi(x)/(x*eps) when c2eps is correctly set
>> 919 x0func->set_domain(1e-6*angstrom/au, 0.9999*screen->xmax()/au); // needed for inverse function
>> 920 // use the c2_inverse_function interface for the root finder... it is more efficient for an ordered
>> 921 // computation of values.
>> 922 G4_c2_ptr x0_solution(c2.inverse_function(x0func));
>> 923
>> 924 G4double m1c2=a1*amu_c2;
>> 925 G4double escale=z1*Z*elm_coupling/au; // energy at screening distance
>> 926 G4double emax=m1c2; // model is doubtful in very relativistic range
>> 927 G4double eratkin=0.9999*(4*a1*a2)/((a1+a2)*(a1+a2)); // #maximum kinematic ratio possible at 180 degrees
>> 928 G4double cmfact0=st.emin/cm_energy(a1, a2, st.emin);
>> 929 G4double l1=std::log(emax);
>> 930 G4double l0=std::log(st.emin*cmfact0/eratkin);
>> 931
>> 932 if(verbosity >=1)
>> 933 G4cout << "Native Screening: " << screeningKey << " " << z1 << " " << a1 << " " <<
>> 934 Z << " " << a2 << " " << recoilCutoff << G4endl;
>> 935
>> 936 for(size_t idx=0; idx<sigLen; idx++) {
>> 937 G4double ee=std::exp(idx*((l1-l0)/sigLen)+l0);
>> 938 G4double gamma=1.0+ee/m1c2;
>> 939 G4double eratio=(cmfact0*st.emin)/ee; // factor by which ee needs to be reduced to get emin
>> 940 G4double theta=thetac(gamma*a1, a2, eratio);
>> 941
>> 942 G4double eps=cm_energy(a1, a2, ee)/escale; // #make sure lab energy is converted to CM for these calculations
>> 943 c2eps.reset(0.0, 0.0, eps); // set correct slope in this function
>> 944
>> 945 G4double q=theta/pi;
>> 946 // G4cout << ee << " " << m1c2 << " " << gamma << " " << eps << " " << theta << " " << q << G4endl;
>> 947 // old way using root finder
>> 948 // G4double x0= x0func->find_root(1e-6*angstrom/au, 0.9999*screen.xmax()/au, 1.0, 2*q-q*q);
>> 949 // new way using c2_inverse_function which caches useful information so should be a bit faster
>> 950 // since we are scanning this in strict order.
>> 951 G4double x0=0;
>> 952 try {
>> 953 x0=x0_solution(2*q-q*q);
>> 954 } catch(c2_exception e) {
>> 955 //G4Exception(G4String("G4ScreenedNuclearRecoil: failure in inverse solution to generate MFP Tables: ")+e.what());
>> 956 }
>> 957 G4double betasquared=x0*x0 - x0*phiau(x0)/eps;
>> 958 G4double sigma=pi*betasquared*au*au;
>> 959 energies[idx]=ee;
>> 960 data[idx]=sigma;
>> 961 }
>> 962 screeningData[Z]=st;
>> 963 sigmaMap[Z] = c2.log_log_interpolating_function().load(energies, data, true,0,true,0);
>> 964 }
1067 } 965 }
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 } 966 }
1078 967