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1 // 1 2 // ******************************************* 3 // * License and Disclaimer 4 // * 5 // * The Geant4 software is copyright of th 6 // * the Geant4 Collaboration. It is provided 7 // * conditions of the Geant4 Software License 8 // * LICENSE and available at http://cern.ch/ 9 // * include a list of copyright holders. 10 // * 11 // * Neither the authors of this software syst 12 // * institutes,nor the agencies providing fin 13 // * work make any representation or warran 14 // * regarding this software system or assum 15 // * use. Please see the license in the file 16 // * for the full disclaimer and the limitatio 17 // * 18 // * This code implementation is the result 19 // * technical work of the GEANT4 collaboratio 20 // * By using, copying, modifying or distri 21 // * any work based on the software) you ag 22 // * use in resulting scientific publicati 23 // * acceptance of all terms of the Geant4 Sof 24 // ******************************************* 25 // 26 // 27 // ------------------------------------------- 28 // 29 // GEANT4 Class file 30 // 31 // 32 // File name: G4EmElementSelector 33 // 34 // Author: Vladimir Ivanchenko 35 // 36 // Creation date: 29.05.2008 37 // 38 // Modifications: 39 // 40 // Class Description: 41 // 42 // Generic helper class for the random selecti 43 44 // ------------------------------------------- 45 // 46 47 #include "G4EmElementSelector.hh" 48 #include "G4VEmModel.hh" 49 #include "G4SystemOfUnits.hh" 50 51 //....oooOO0OOooo........oooOO0OOooo........oo 52 //....oooOO0OOooo........oooOO0OOooo........oo 53 54 G4EmElementSelector::G4EmElementSelector(G4VEm 55 const 56 G4int 57 G4dou 58 G4dou 59 G4boo 60 model(mod), material(mat), nbins(bins), cutE 61 lowEnergy(emin), highEnergy(emax) 62 { 63 G4int n = (G4int)material->GetNumberOfElemen 64 nElmMinusOne = n - 1; 65 theElementVector = material->GetElementVecto 66 if(nElmMinusOne > 0) { 67 xSections.reserve(n); 68 auto v0 = new G4PhysicsLogVector(lowEnergy 69 xSections.push_back(v0); 70 for(G4int i=1; i<n; ++i) { 71 auto v = new G4PhysicsLogVector(*v0); 72 xSections.push_back(v); 73 } 74 } 75 /* 76 G4cout << "G4EmElementSelector for " << mat- 77 << " nbins= " << nbins << " Emin= " 78 << " Emax= " << highEnergy << G4endl; 79 */ 80 } 81 82 //....oooOO0OOooo........oooOO0OOooo........oo 83 84 G4EmElementSelector::~G4EmElementSelector() 85 { 86 if(nElmMinusOne > 0) { 87 for(G4int i=0; i<=nElmMinusOne; ++i) { del 88 } 89 } 90 91 //....oooOO0OOooo........oooOO0OOooo........oo 92 93 void G4EmElementSelector::Initialise(const G4P 94 G4double 95 { 96 //G4cout << "G4EmElementSelector initialise 97 // << G4endl; 98 if(0 == nElmMinusOne || cut == cutEnergy) { 99 100 cutEnergy = cut; 101 //G4cout << "cut(keV)= " << cut/keV << G4end 102 G4double cross; 103 104 const G4double* theAtomNumDensityVector = 105 material->GetVecNbOfAtomsPerVolume(); 106 107 // loop over bins 108 for(G4int j=0; j<=nbins; ++j) { 109 G4double e = (xSections[0])->Energy(j); 110 model->SetupForMaterial(part, material, e) 111 cross = 0.0; 112 //G4cout << "j= " << j << " e(MeV)= " << e 113 for (G4int i=0; i<=nElmMinusOne; ++i) { 114 cross += theAtomNumDensityVector[i]* 115 model->ComputeCrossSectionPerAtom(part 116 cutE 117 xSections[i]->PutValue(j, cross); 118 } 119 } 120 // xSections start from null, so use probabi 121 if(0.0 == (*xSections[nElmMinusOne])[0]) { 122 for (G4int i=0; i<=nElmMinusOne; ++i) { 123 xSections[i]->PutValue(0, (*xSections[i] 124 } 125 } 126 // xSections ends with null, so use probabil 127 if(0.0 == (*xSections[nElmMinusOne])[nbins]) 128 for (G4int i=0; i<=nElmMinusOne; ++i) { 129 xSections[i]->PutValue(nbins, (*xSection 130 } 131 } 132 // perform normalization 133 for(G4int j=0; j<=nbins; ++j) { 134 cross = (*xSections[nElmMinusOne])[j]; 135 // only for positive X-section 136 if(cross > 0.0) { 137 for (G4int i=0; i<nElmMinusOne; ++i) { 138 G4double x = (*xSections[i])[j]/cross; 139 xSections[i]->PutValue(j, x); 140 } 141 } 142 } 143 /* 144 G4cout << "======== G4EmElementSelector for 145 << G4endl; 146 for (G4int i=0; i<=nElmMinusOne; ++i) { 147 G4cout << "#### i=" << i << G4endl; 148 G4cout << (*xSections[i]) << G4endl; 149 } 150 */ 151 } 152 153 //....oooOO0OOooo........oooOO0OOooo........oo 154 155 const G4Element* 156 G4EmElementSelector::SelectRandomAtom(const G4 157 const G4 158 { 159 const G4Element* element = (*theElementVecto 160 if (nElmMinusOne > 0) { 161 // 1. Determine energy index (only once) 162 // handle cases below/above the enrgy grid 163 // ekin = x[0] if e<=x[0] and idx will 164 // ekin = x[N-1] if e>=x[N-1] and idx will 165 G4double ekin = e; 166 std::size_t idx = 0; 167 if(e <= (xSections[0])->Energy(0)) { 168 ekin = (xSections[0])->Energy(0); 169 } else if(e < (xSections[0])->GetMaxEnergy 170 idx = (xSections[0])->ComputeLogVectorBi 171 } else { 172 ekin = (xSections[0])->GetMaxEnergy(); 173 idx = (xSections[0])->GetVectorLength() 174 } 175 // 2. Do the linear interp.(corner cases a 176 const G4double x1 = (xSections[0])->Energy 177 const G4double a = (ekin - x1)/((xSection 178 const G4double urnd = G4UniformRand(); 179 for (G4int i = 0; i < nElmMinusOne; ++i) { 180 const G4double y1 = (*xSections[i])[idx 181 if (urnd <= y1 + a*((*xSections[i])[idx+ 182 element = (*theElementVector)[i]; 183 break; 184 } 185 } 186 } 187 return element; 188 } 189 190 //....oooOO0OOooo........oooOO0OOooo........oo 191 192 void G4EmElementSelector::Dump(const G4Particl 193 { 194 G4cout << "======== G4EmElementSelector for 195 if(part) G4cout << " and " << part->GetParti 196 G4cout << " for " << material->GetName() << 197 if(0 < nElmMinusOne) { 198 for(G4int i=0; i<nElmMinusOne; i++) { 199 G4cout << " " << (*theElementVector 200 G4cout << *(xSections[i]) << G4endl; 201 } 202 } 203 G4cout << "Last Element in element vector " 204 << (*theElementVector)[nElmMinusOne]- 205 << G4endl; 206 G4cout << G4endl; 207 } 208 209 //....oooOO0OOooo........oooOO0OOooo........oo 210 211 212