1 | // |
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2 | // ******************************************************************** |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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24 | // ******************************************************************** |
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25 | // |
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26 | // $Id: G4PenelopePhotoElectricModel.cc,v 1.3 2009/01/08 09:42:54 pandola Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-02-ref-02 $ |
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28 | // |
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29 | // Author: Luciano Pandola |
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30 | // |
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31 | // History: |
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32 | // -------- |
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33 | // 08 Oct 2008 L Pandola Migration from process to model |
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34 | // 08 Jan 2009 L. Pandola Check shell index to avoid mismatch between |
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35 | // the Penelope cross section database and the |
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36 | // G4AtomicTransitionManager database. It suppresses |
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37 | // a warning from G4AtomicTransitionManager only. |
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38 | // Results are unchanged. |
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39 | // |
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40 | |
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41 | #include "G4PenelopePhotoElectricModel.hh" |
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42 | #include "G4ParticleDefinition.hh" |
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43 | #include "G4MaterialCutsCouple.hh" |
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44 | #include "G4ProductionCutsTable.hh" |
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45 | #include "G4DynamicParticle.hh" |
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46 | #include "G4PhysicsTable.hh" |
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47 | #include "G4ElementTable.hh" |
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48 | #include "G4Element.hh" |
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49 | #include "G4CrossSectionHandler.hh" |
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50 | #include "G4AtomicTransitionManager.hh" |
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51 | #include "G4AtomicShell.hh" |
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52 | #include "G4Gamma.hh" |
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53 | #include "G4Electron.hh" |
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54 | |
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55 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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56 | |
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57 | |
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58 | G4PenelopePhotoElectricModel::G4PenelopePhotoElectricModel(const G4ParticleDefinition*, |
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59 | const G4String& nam) |
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60 | :G4VEmModel(nam),isInitialised(false),crossSectionHandler(0), |
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61 | shellCrossSectionHandler(0) |
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62 | { |
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63 | fIntrinsicLowEnergyLimit = 100.0*eV; |
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64 | fIntrinsicHighEnergyLimit = 100.0*GeV; |
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65 | SetLowEnergyLimit(fIntrinsicLowEnergyLimit); |
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66 | SetHighEnergyLimit(fIntrinsicHighEnergyLimit); |
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67 | // |
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68 | fUseAtomicDeexcitation = true; |
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69 | verboseLevel= 0; |
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70 | // Verbosity scale: |
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71 | // 0 = nothing |
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72 | // 1 = warning for energy non-conservation |
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73 | // 2 = details of energy budget |
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74 | // 3 = calculation of cross sections, file openings, sampling of atoms |
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75 | // 4 = entering in methods |
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76 | } |
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77 | |
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78 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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79 | |
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80 | G4PenelopePhotoElectricModel::~G4PenelopePhotoElectricModel() |
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81 | { |
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82 | if (crossSectionHandler) delete crossSectionHandler; |
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83 | if (shellCrossSectionHandler) delete shellCrossSectionHandler; |
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84 | } |
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85 | |
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86 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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87 | |
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88 | void G4PenelopePhotoElectricModel::Initialise(const G4ParticleDefinition*, |
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89 | const G4DataVector& ) |
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90 | { |
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91 | if (verboseLevel > 3) |
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92 | G4cout << "Calling G4PenelopePhotoElectricModel::Initialise()" << G4endl; |
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93 | if (crossSectionHandler) |
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94 | { |
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95 | crossSectionHandler->Clear(); |
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96 | delete crossSectionHandler; |
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97 | } |
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98 | if (shellCrossSectionHandler) |
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99 | { |
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100 | shellCrossSectionHandler->Clear(); |
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101 | delete shellCrossSectionHandler; |
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102 | } |
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103 | |
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104 | //Check energy limits |
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105 | if (LowEnergyLimit() < fIntrinsicLowEnergyLimit) |
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106 | { |
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107 | G4cout << "G4PenelopePhotoElectricModel: low energy limit increased from " << |
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108 | LowEnergyLimit()/eV << " eV to " << fIntrinsicLowEnergyLimit/eV << " eV" << |
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109 | G4endl; |
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110 | SetLowEnergyLimit(fIntrinsicLowEnergyLimit); |
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111 | } |
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112 | if (HighEnergyLimit() > fIntrinsicHighEnergyLimit) |
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113 | { |
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114 | G4cout << "G4PenelopePhotoElectricModel: high energy limit decreased from " << |
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115 | HighEnergyLimit()/GeV << " GeV to " << fIntrinsicHighEnergyLimit/GeV << " GeV" |
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116 | << G4endl; |
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117 | SetHighEnergyLimit(fIntrinsicHighEnergyLimit); |
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118 | } |
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119 | |
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120 | |
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121 | //Re-initialize cross section handlers |
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122 | crossSectionHandler = new G4CrossSectionHandler(); |
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123 | crossSectionHandler->Clear(); |
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124 | G4String crossSectionFile = "penelope/ph-cs-pen-"; |
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125 | crossSectionHandler->LoadData(crossSectionFile); |
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126 | shellCrossSectionHandler = new G4CrossSectionHandler(); |
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127 | shellCrossSectionHandler->Clear(); |
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128 | crossSectionFile = "penelope/ph-ss-cs-pen-"; |
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129 | shellCrossSectionHandler->LoadShellData(crossSectionFile); |
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130 | //This is used to retrieve cross section values later on |
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131 | crossSectionHandler->BuildMeanFreePathForMaterials(); |
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132 | |
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133 | if (verboseLevel > 2) |
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134 | G4cout << "Loaded cross section files for PenelopePhotoElectric" << G4endl; |
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135 | |
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136 | G4cout << "Penelope Photo-Electric model is initialized " << G4endl |
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137 | << "Energy range: " |
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138 | << LowEnergyLimit() / MeV << " MeV - " |
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139 | << HighEnergyLimit() / GeV << " GeV" |
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140 | << G4endl; |
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141 | |
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142 | if(isInitialised) return; |
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143 | |
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144 | if(pParticleChange) |
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145 | fParticleChange = reinterpret_cast<G4ParticleChangeForGamma*>(pParticleChange); |
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146 | else |
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147 | fParticleChange = new G4ParticleChangeForGamma(); |
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148 | isInitialised = true; |
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149 | } |
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150 | |
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151 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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152 | |
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153 | G4double G4PenelopePhotoElectricModel::ComputeCrossSectionPerAtom( |
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154 | const G4ParticleDefinition*, |
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155 | G4double energy, |
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156 | G4double Z, G4double, |
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157 | G4double, G4double) |
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158 | { |
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159 | // |
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160 | // Penelope model. Use data-driven approach for cross section estimate (and |
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161 | // also shell sampling from a given atom). Data are from the Livermore database |
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162 | // D.E. Cullen et al., Report UCRL-50400 (1989) |
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163 | // |
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164 | |
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165 | if (verboseLevel > 3) |
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166 | G4cout << "Calling ComputeCrossSectionPerAtom() of G4PenelopePhotoElectricModel" << G4endl; |
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167 | |
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168 | G4int iZ = (G4int) Z; |
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169 | if (!crossSectionHandler) |
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170 | { |
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171 | G4cout << "G4PenelopePhotoElectricModel::ComputeCrossSectionPerAtom" << G4endl; |
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172 | G4cout << "The cross section handler is not correctly initialized" << G4endl; |
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173 | G4Exception(); |
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174 | } |
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175 | G4double cs = crossSectionHandler->FindValue(iZ,energy); |
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176 | |
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177 | if (verboseLevel > 2) |
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178 | G4cout << "Photoelectric cross section at " << energy/MeV << " MeV for Z=" << Z << |
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179 | " = " << cs/barn << " barn" << G4endl; |
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180 | return cs; |
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181 | } |
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182 | |
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183 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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184 | |
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185 | void G4PenelopePhotoElectricModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect, |
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186 | const G4MaterialCutsCouple* couple, |
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187 | const G4DynamicParticle* aDynamicGamma, |
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188 | G4double, |
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189 | G4double) |
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190 | { |
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191 | // |
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192 | // Photoelectric effect, Penelope model |
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193 | // |
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194 | // The target atom and the target shell are sampled according to the Livermore |
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195 | // database |
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196 | // D.E. Cullen et al., Report UCRL-50400 (1989) |
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197 | // The angular distribution of the electron in the final state is sampled |
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198 | // according to the Sauter distribution from |
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199 | // F. Sauter, Ann. Phys. 11 (1931) 454 |
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200 | // The energy of the final electron is given by the initial photon energy minus |
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201 | // the binding energy. Fluorescence de-excitation is subsequently produced |
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202 | // (to fill the vacancy) according to the general Geant4 G4DeexcitationManager: |
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203 | // J. Stepanek, Comp. Phys. Comm. 1206 pp 1-1-9 (1997) |
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204 | |
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205 | if (verboseLevel > 3) |
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206 | G4cout << "Calling SamplingSecondaries() of G4PenelopePhotoElectricModel" << G4endl; |
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207 | |
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208 | G4double photonEnergy = aDynamicGamma->GetKineticEnergy(); |
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209 | |
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210 | if (photonEnergy <= LowEnergyLimit()) |
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211 | { |
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212 | fParticleChange->ProposeTrackStatus(fStopAndKill); |
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213 | fParticleChange->SetProposedKineticEnergy(0.); |
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214 | fParticleChange->ProposeLocalEnergyDeposit(photonEnergy); |
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215 | return ; |
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216 | } |
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217 | |
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218 | G4ParticleMomentum photonDirection = aDynamicGamma->GetMomentumDirection(); |
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219 | |
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220 | // Select randomly one element in the current material |
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221 | if (verboseLevel > 2) |
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222 | G4cout << "Going to select element in " << couple->GetMaterial()->GetName() << G4endl; |
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223 | //use crossSectionHandler instead of G4EmElementSelector because in this case |
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224 | //the dimension of the table is equal to the dimension of the database (less interpolation errors) |
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225 | G4int Z = crossSectionHandler->SelectRandomAtom(couple,photonEnergy); |
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226 | if (verboseLevel > 2) |
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227 | G4cout << "Selected Z = " << Z << G4endl; |
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228 | |
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229 | // Select the ionised shell in the current atom according to shell cross sections |
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230 | size_t shellIndex = shellCrossSectionHandler->SelectRandomShell(Z,photonEnergy); |
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231 | |
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232 | // Retrieve the corresponding identifier and binding energy of the selected shell |
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233 | const G4AtomicTransitionManager* transitionManager = G4AtomicTransitionManager::Instance(); |
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234 | |
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235 | //The number of shell cross section possibly reported in the Penelope database |
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236 | //might be different from the number of shells in the G4AtomicTransitionManager |
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237 | //(namely, Penelope may contain more shell, especially for very light elements). |
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238 | //In order to avoid a warning message from the G4AtomicTransitionManager, I |
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239 | //add this protection. Results are anyway changed, because when G4AtomicTransitionManager |
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240 | //has a shellID>maxID, it sets the shellID to the last valid shell. |
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241 | size_t numberOfShells = (size_t) transitionManager->NumberOfShells(Z); |
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242 | if (shellIndex >= numberOfShells) |
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243 | shellIndex = numberOfShells-1; |
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244 | |
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245 | const G4AtomicShell* shell = transitionManager->Shell(Z,shellIndex); |
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246 | G4double bindingEnergy = shell->BindingEnergy(); |
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247 | G4int shellId = shell->ShellId(); |
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248 | |
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249 | G4double localEnergyDeposit = 0.0; |
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250 | |
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251 | // Primary outcoming electron |
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252 | G4double eKineticEnergy = photonEnergy - bindingEnergy; |
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253 | |
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254 | G4double cutForLowEnergySecondaryParticles = 250.0*eV; |
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255 | const G4ProductionCutsTable* theCoupleTable= |
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256 | G4ProductionCutsTable::GetProductionCutsTable(); |
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257 | size_t indx = couple->GetIndex(); |
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258 | G4double cutE = (*(theCoupleTable->GetEnergyCutsVector(1)))[indx]; |
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259 | cutE = std::max(cutForLowEnergySecondaryParticles,cutE); |
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260 | |
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261 | // There may be cases where the binding energy of the selected shell is > photon energy |
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262 | // In such cases do not generate secondaries |
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263 | if (eKineticEnergy > 0.) |
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264 | { |
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265 | //Now check if the electron is above cuts: if so, it is created explicitely |
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266 | if (eKineticEnergy > cutE) |
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267 | { |
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268 | // The electron is created |
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269 | // Direction sampled from the Sauter distribution |
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270 | G4double cosTheta = SampleElectronDirection(eKineticEnergy); |
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271 | G4double sinTheta = std::sqrt(1-cosTheta*cosTheta); |
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272 | G4double phi = twopi * G4UniformRand() ; |
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273 | G4double dirx = sinTheta * std::cos(phi); |
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274 | G4double diry = sinTheta * std::sin(phi); |
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275 | G4double dirz = cosTheta ; |
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276 | G4ThreeVector electronDirection(dirx,diry,dirz); //electron direction |
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277 | electronDirection.rotateUz(photonDirection); |
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278 | G4DynamicParticle* electron = new G4DynamicParticle (G4Electron::Electron(), |
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279 | electronDirection, |
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280 | eKineticEnergy); |
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281 | fvect->push_back(electron); |
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282 | } |
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283 | else |
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284 | localEnergyDeposit += eKineticEnergy; |
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285 | } |
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286 | else |
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287 | bindingEnergy = photonEnergy; |
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288 | |
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289 | |
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290 | G4double energyInFluorescence = 0; //testing purposes |
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291 | |
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292 | //Now, take care of fluorescence, if required |
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293 | if (fUseAtomicDeexcitation) |
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294 | { |
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295 | G4double cutG = (*(theCoupleTable->GetEnergyCutsVector(0)))[indx]; |
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296 | cutG = std::min(cutForLowEnergySecondaryParticles,cutG); |
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297 | |
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298 | std::vector<G4DynamicParticle*>* photonVector = 0; |
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299 | |
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300 | // Protection to avoid generating photons in the unphysical case of |
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301 | // shell binding energy > photon energy |
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302 | if (Z > 5 && (bindingEnergy > cutG || bindingEnergy > cutE)) |
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303 | { |
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304 | photonVector = deexcitationManager.GenerateParticles(Z,shellId); |
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305 | //Check for single photons (if they are above threshold) |
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306 | for (size_t k=0; k< photonVector->size(); k++) |
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307 | { |
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308 | G4DynamicParticle* aPhoton = (*photonVector)[k]; |
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309 | if (aPhoton) |
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310 | { |
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311 | G4double itsCut = cutG; |
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312 | if(aPhoton->GetDefinition() == G4Electron::Electron()) itsCut = cutE; |
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313 | G4double itsEnergy = aPhoton->GetKineticEnergy(); |
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314 | |
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315 | if (itsEnergy > itsCut && itsEnergy <= bindingEnergy) |
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316 | { |
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317 | // Local energy deposit is given as the sum of the |
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318 | // energies of incident photons minus the energies |
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319 | // of the outcoming fluorescence photons |
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320 | bindingEnergy -= itsEnergy; |
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321 | |
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322 | } |
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323 | else |
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324 | { |
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325 | (*photonVector)[k] = 0; |
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326 | } |
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327 | } |
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328 | } |
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329 | } |
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330 | //Register valid secondaries |
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331 | if (photonVector) |
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332 | { |
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333 | for ( size_t ll = 0; ll <photonVector->size(); ll++) |
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334 | { |
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335 | G4DynamicParticle* aPhoton = (*photonVector)[ll]; |
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336 | if (aPhoton) |
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337 | { |
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338 | energyInFluorescence += aPhoton->GetKineticEnergy(); |
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339 | fvect->push_back(aPhoton); |
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340 | } |
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341 | } |
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342 | delete photonVector; |
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343 | } |
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344 | } |
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345 | //Residual energy is deposited locally |
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346 | localEnergyDeposit += bindingEnergy; |
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347 | |
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348 | |
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349 | if (localEnergyDeposit < 0) |
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350 | { |
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351 | G4cout << "WARNING - " |
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352 | << "G4PenelopePhotoElectric::PostStepDoIt - Negative energy deposit" |
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353 | << G4endl; |
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354 | localEnergyDeposit = 0; |
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355 | } |
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356 | |
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357 | //Update the status of the primary gamma (kill it) |
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358 | fParticleChange->SetProposedKineticEnergy(0.); |
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359 | fParticleChange->ProposeLocalEnergyDeposit(localEnergyDeposit); |
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360 | fParticleChange->ProposeTrackStatus(fStopAndKill); |
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361 | |
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362 | if (verboseLevel > 1) |
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363 | { |
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364 | G4cout << "-----------------------------------------------------------" << G4endl; |
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365 | G4cout << "Energy balance from G4PenelopePhotoElectric" << G4endl; |
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366 | G4cout << "Incoming photon energy: " << photonEnergy/keV << " keV" << G4endl; |
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367 | G4cout << "-----------------------------------------------------------" << G4endl; |
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368 | if (eKineticEnergy) |
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369 | G4cout << "Outgoing electron " << eKineticEnergy/keV << " keV" << G4endl; |
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370 | G4cout << "Fluorescence: " << energyInFluorescence/keV << " keV" << G4endl; |
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371 | G4cout << "Local energy deposit " << localEnergyDeposit/keV << " keV" << G4endl; |
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372 | G4cout << "Total final state: " << (eKineticEnergy+energyInFluorescence+localEnergyDeposit)/keV << |
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373 | " keV" << G4endl; |
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374 | G4cout << "-----------------------------------------------------------" << G4endl; |
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375 | } |
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376 | if (verboseLevel > 0) |
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377 | { |
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378 | G4double energyDiff = std::fabs(eKineticEnergy+energyInFluorescence+localEnergyDeposit-photonEnergy); |
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379 | if (energyDiff > 0.05*keV) |
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380 | G4cout << "Warning from G4PenelopePhotoElectric: problem with energy conservation: " << |
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381 | (eKineticEnergy+energyInFluorescence+localEnergyDeposit)/keV << " keV (final) vs. " << |
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382 | photonEnergy/keV << " keV (initial)" << G4endl; |
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383 | } |
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384 | } |
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385 | |
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386 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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387 | |
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388 | void G4PenelopePhotoElectricModel::ActivateAuger(G4bool augerbool) |
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389 | { |
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390 | if (!fUseAtomicDeexcitation) |
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391 | { |
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392 | G4cout << "WARNING - G4PenelopePhotoElectricModel" << G4endl; |
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393 | G4cout << "The use of the Atomic Deexcitation Manager is set to false " << G4endl; |
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394 | G4cout << "Therefore, Auger electrons will be not generated anyway" << G4endl; |
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395 | } |
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396 | deexcitationManager.ActivateAugerElectronProduction(augerbool); |
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397 | if (verboseLevel > 1) |
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398 | G4cout << "Auger production set to " << augerbool << G4endl; |
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399 | } |
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400 | |
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401 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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402 | |
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403 | G4double G4PenelopePhotoElectricModel::SampleElectronDirection(G4double energy) |
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404 | { |
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405 | G4double costheta = 1.0; |
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406 | if (energy>1*GeV) return costheta; |
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407 | |
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408 | //1) initialize energy-dependent variables |
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409 | // Variable naming according to Eq. (2.24) of Penelope Manual |
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410 | // (pag. 44) |
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411 | G4double gamma = 1.0 + energy/electron_mass_c2; |
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412 | G4double gamma2 = gamma*gamma; |
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413 | G4double beta = std::sqrt((gamma2-1.0)/gamma2); |
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414 | |
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415 | // ac corresponds to "A" of Eq. (2.31) |
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416 | // |
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417 | G4double ac = (1.0/beta) - 1.0; |
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418 | G4double a1 = 0.5*beta*gamma*(gamma-1.0)*(gamma-2.0); |
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419 | G4double a2 = ac + 2.0; |
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420 | G4double gtmax = 2.0*(a1 + 1.0/ac); |
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421 | |
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422 | G4double tsam = 0; |
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423 | G4double gtr = 0; |
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424 | |
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425 | //2) sampling. Eq. (2.31) of Penelope Manual |
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426 | // tsam = 1-std::cos(theta) |
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427 | // gtr = rejection function according to Eq. (2.28) |
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428 | do{ |
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429 | G4double rand = G4UniformRand(); |
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430 | tsam = 2.0*ac * (2.0*rand + a2*std::sqrt(rand)) / (a2*a2 - 4.0*rand); |
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431 | gtr = (2.0 - tsam) * (a1 + 1.0/(ac+tsam)); |
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432 | }while(G4UniformRand()*gtmax > gtr); |
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433 | costheta = 1.0-tsam; |
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434 | return costheta; |
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435 | } |
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436 | |
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