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24 | // ******************************************************************** |
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25 | // |
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26 | // $Id: G4PEEffectFluoModel.cc,v 1.1 2010/09/03 14:11:16 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: emstand-V09-03-24 $ |
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28 | // |
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29 | // ------------------------------------------------------------------- |
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30 | // |
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31 | // GEANT4 Class file |
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32 | // |
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33 | // |
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34 | // File name: G4PEEffectFluoModel |
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35 | // |
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36 | // Author: Vladimir Ivanchenko on base of G4PEEffectModel |
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37 | // |
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38 | // Creation date: 13.06.2010 |
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39 | // |
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40 | // Modifications: |
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41 | // |
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42 | // Class Description: |
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43 | // Implementation of the photo-electric effect with deexcitation |
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44 | // |
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45 | // ------------------------------------------------------------------- |
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46 | // |
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47 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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48 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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49 | |
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50 | #include "G4PEEffectFluoModel.hh" |
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51 | #include "G4Electron.hh" |
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52 | #include "G4Gamma.hh" |
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53 | #include "Randomize.hh" |
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54 | #include "G4DataVector.hh" |
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55 | #include "G4ParticleChangeForGamma.hh" |
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56 | #include "G4VAtomDeexcitation.hh" |
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57 | #include "G4LossTableManager.hh" |
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58 | |
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59 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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60 | |
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61 | using namespace std; |
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62 | |
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63 | G4PEEffectFluoModel::G4PEEffectFluoModel(const G4String& nam) |
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64 | : G4VEmModel(nam),isInitialized(false) |
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65 | { |
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66 | theGamma = G4Gamma::Gamma(); |
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67 | theElectron = G4Electron::Electron(); |
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68 | fminimalEnergy = 1.0*eV; |
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69 | } |
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70 | |
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71 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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72 | |
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73 | G4PEEffectFluoModel::~G4PEEffectFluoModel() |
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74 | {} |
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75 | |
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76 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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77 | |
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78 | void G4PEEffectFluoModel::Initialise(const G4ParticleDefinition*, |
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79 | const G4DataVector&) |
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80 | { |
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81 | fAtomDeexcitation = G4LossTableManager::Instance()->AtomDeexcitation(); |
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82 | |
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83 | if (isInitialized) return; |
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84 | fParticleChange = GetParticleChangeForGamma(); |
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85 | isInitialized = true; |
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86 | } |
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87 | |
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88 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo..... |
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89 | |
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90 | G4double |
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91 | G4PEEffectFluoModel::ComputeCrossSectionPerAtom(const G4ParticleDefinition*, |
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92 | G4double energy, |
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93 | G4double Z, G4double, |
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94 | G4double, G4double) |
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95 | { |
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96 | G4double* SandiaCof = G4SandiaTable::GetSandiaCofPerAtom((G4int)Z, energy); |
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97 | |
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98 | G4double energy2 = energy*energy; |
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99 | G4double energy3 = energy*energy2; |
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100 | G4double energy4 = energy2*energy2; |
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101 | |
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102 | return SandiaCof[0]/energy + SandiaCof[1]/energy2 + |
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103 | SandiaCof[2]/energy3 + SandiaCof[3]/energy4; |
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104 | } |
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105 | |
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106 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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107 | |
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108 | G4double |
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109 | G4PEEffectFluoModel::CrossSectionPerVolume(const G4Material* material, |
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110 | const G4ParticleDefinition*, |
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111 | G4double energy, |
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112 | G4double, G4double) |
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113 | { |
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114 | G4double* SandiaCof = |
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115 | material->GetSandiaTable()->GetSandiaCofForMaterial(energy); |
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116 | |
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117 | G4double energy2 = energy*energy; |
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118 | G4double energy3 = energy*energy2; |
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119 | G4double energy4 = energy2*energy2; |
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120 | |
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121 | return SandiaCof[0]/energy + SandiaCof[1]/energy2 + |
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122 | SandiaCof[2]/energy3 + SandiaCof[3]/energy4; |
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123 | } |
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124 | |
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125 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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126 | |
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127 | void |
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128 | G4PEEffectFluoModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect, |
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129 | const G4MaterialCutsCouple* couple, |
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130 | const G4DynamicParticle* aDynamicPhoton, |
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131 | G4double, |
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132 | G4double) |
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133 | { |
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134 | const G4Material* aMaterial = couple->GetMaterial(); |
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135 | |
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136 | G4double energy = aDynamicPhoton->GetKineticEnergy(); |
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137 | G4ParticleMomentum PhotonDirection = aDynamicPhoton->GetMomentumDirection(); |
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138 | |
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139 | // select randomly one element constituing the material. |
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140 | const G4Element* anElement = SelectRandomAtom(aMaterial,theGamma,energy); |
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141 | |
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142 | // |
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143 | // Photo electron |
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144 | // |
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145 | |
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146 | // Select atomic shell |
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147 | G4int nShells = anElement->GetNbOfAtomicShells(); |
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148 | G4int i = 0; |
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149 | while ((i<nShells) && (energy<anElement->GetAtomicShell(i))) { ++i; } |
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150 | |
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151 | // no shell available |
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152 | if (i == nShells) { return; } |
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153 | |
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154 | G4double bindingEnergy = anElement->GetAtomicShell(i); |
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155 | G4double ElecKineEnergy = energy - bindingEnergy; |
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156 | |
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157 | // create photo electron |
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158 | // |
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159 | if (ElecKineEnergy > fminimalEnergy) { |
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160 | G4double cosTeta = ElecCosThetaDistribution(ElecKineEnergy); |
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161 | G4double sinTeta = sqrt(1.-cosTeta*cosTeta); |
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162 | G4double Phi = twopi * G4UniformRand(); |
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163 | G4double dirx = sinTeta*cos(Phi),diry = sinTeta*sin(Phi),dirz = cosTeta; |
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164 | G4ThreeVector ElecDirection(dirx,diry,dirz); |
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165 | ElecDirection.rotateUz(PhotonDirection); |
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166 | // |
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167 | G4DynamicParticle* aParticle = new G4DynamicParticle ( |
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168 | theElectron,ElecDirection, ElecKineEnergy); |
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169 | fvect->push_back(aParticle); |
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170 | } |
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171 | |
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172 | // sample deexcitation |
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173 | // |
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174 | if(fAtomDeexcitation) { |
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175 | G4int Z = (G4int)anElement->GetZ(); |
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176 | G4AtomicShellEnumerator as = G4AtomicShellEnumerator(i); |
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177 | const G4AtomicShell* shell = fAtomDeexcitation->GetAtomicShell(Z, as); |
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178 | fAtomDeexcitation->GenerateParticles(fvect, shell, Z, couple->GetIndex()); |
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179 | } |
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180 | |
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181 | // kill primary photon |
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182 | fParticleChange->SetProposedKineticEnergy(0.); |
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183 | fParticleChange->ProposeTrackStatus(fStopAndKill); |
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184 | fParticleChange->ProposeLocalEnergyDeposit(bindingEnergy); |
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185 | } |
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186 | |
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187 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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188 | |
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189 | G4double G4PEEffectFluoModel::ElecCosThetaDistribution(G4double kineEnergy) |
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190 | { |
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191 | // Compute Theta distribution of the emitted electron, with respect to the |
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192 | // incident Gamma. |
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193 | // The Sauter-Gavrila distribution for the K-shell is used. |
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194 | // |
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195 | G4double costeta = 1.; |
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196 | G4double gamma = 1. + kineEnergy/electron_mass_c2; |
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197 | if (gamma > 5.) return costeta; |
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198 | G4double beta = sqrt(gamma*gamma-1.)/gamma; |
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199 | G4double b = 0.5*gamma*(gamma-1.)*(gamma-2); |
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200 | |
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201 | G4double rndm,term,greject,grejsup; |
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202 | if (gamma < 2.) grejsup = gamma*gamma*(1.+b-beta*b); |
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203 | else grejsup = gamma*gamma*(1.+b+beta*b); |
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204 | |
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205 | do { rndm = 1.-2*G4UniformRand(); |
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206 | costeta = (rndm+beta)/(rndm*beta+1.); |
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207 | term = 1.-beta*costeta; |
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208 | greject = (1.-costeta*costeta)*(1.+b*term)/(term*term); |
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209 | } while(greject < G4UniformRand()*grejsup); |
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210 | |
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211 | return costeta; |
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212 | } |
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213 | |
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214 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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