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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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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: G4PEEffectModel.cc,v 1.7 2009/02/20 12:06:37 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-02-ref-02 $ |
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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: G4PEEffectModel |
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35 | // |
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36 | // Author: Vladimir Ivanchenko on base of Michel Maire code |
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37 | // |
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38 | // Creation date: 21.03.2005 |
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39 | // |
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40 | // Modifications: |
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41 | // |
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42 | // 04.12.05 : SetProposedKineticEnergy(0.) for the killed photon (mma) |
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43 | // 20.02.09 : Added initialisation of deexcitation flag and method |
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44 | // CrossSectionPerVolume instead of mfp (V.Ivanchenko) |
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45 | // |
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46 | // Class Description: |
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47 | // |
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48 | // ------------------------------------------------------------------- |
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49 | // |
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50 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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51 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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52 | |
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53 | #include "G4PEEffectModel.hh" |
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54 | #include "G4Electron.hh" |
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55 | #include "G4Gamma.hh" |
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56 | #include "Randomize.hh" |
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57 | #include "G4DataVector.hh" |
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58 | #include "G4ParticleChangeForGamma.hh" |
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59 | |
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60 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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61 | |
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62 | using namespace std; |
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63 | |
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64 | G4PEEffectModel::G4PEEffectModel(const G4ParticleDefinition*, |
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65 | const G4String& nam) |
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66 | : G4VEmModel(nam),isInitialized(false) |
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67 | { |
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68 | theGamma = G4Gamma::Gamma(); |
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69 | theElectron = G4Electron::Electron(); |
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70 | fminimalEnergy = 1.0*eV; |
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71 | } |
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72 | |
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73 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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74 | |
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75 | G4PEEffectModel::~G4PEEffectModel() |
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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 | void G4PEEffectModel::Initialise(const G4ParticleDefinition*, |
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81 | const G4DataVector&) |
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82 | { |
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83 | // always false before the run |
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84 | SetDeexcitationFlag(false); |
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85 | |
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86 | if (isInitialized) return; |
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87 | if (pParticleChange) { |
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88 | fParticleChange = reinterpret_cast<G4ParticleChangeForGamma*>(pParticleChange); |
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89 | } else { |
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90 | fParticleChange = new G4ParticleChangeForGamma(); |
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91 | } |
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92 | isInitialized = true; |
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93 | } |
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94 | |
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95 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo..... |
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96 | |
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97 | G4double G4PEEffectModel::ComputeCrossSectionPerAtom(const G4ParticleDefinition*, |
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98 | G4double energy, |
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99 | G4double Z, G4double, |
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100 | G4double, G4double) |
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101 | { |
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102 | G4double* SandiaCof = G4SandiaTable::GetSandiaCofPerAtom((G4int)Z, energy); |
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103 | |
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104 | G4double energy2 = energy*energy; |
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105 | G4double energy3 = energy*energy2; |
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106 | G4double energy4 = energy2*energy2; |
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107 | |
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108 | return SandiaCof[0]/energy + SandiaCof[1]/energy2 + |
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109 | SandiaCof[2]/energy3 + SandiaCof[3]/energy4; |
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110 | } |
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111 | |
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112 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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113 | |
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114 | G4double G4PEEffectModel::CrossSectionPerVolume(const G4Material* material, |
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115 | const G4ParticleDefinition*, |
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116 | G4double energy, |
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117 | G4double, G4double) |
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118 | { |
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119 | G4double* SandiaCof = |
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120 | material->GetSandiaTable()->GetSandiaCofForMaterial(energy); |
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121 | |
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122 | G4double energy2 = energy*energy; |
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123 | G4double energy3 = energy*energy2; |
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124 | G4double energy4 = energy2*energy2; |
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125 | |
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126 | return SandiaCof[0]/energy + SandiaCof[1]/energy2 + |
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127 | SandiaCof[2]/energy3 + SandiaCof[3]/energy4; |
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128 | } |
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129 | |
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130 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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131 | |
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132 | void G4PEEffectModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect, |
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133 | const G4MaterialCutsCouple* couple, |
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134 | const G4DynamicParticle* aDynamicPhoton, |
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135 | G4double, |
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136 | G4double) |
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137 | { |
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138 | const G4Material* aMaterial = couple->GetMaterial(); |
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139 | |
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140 | G4double energy = aDynamicPhoton->GetKineticEnergy(); |
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141 | G4ParticleMomentum PhotonDirection = aDynamicPhoton->GetMomentumDirection(); |
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142 | |
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143 | // select randomly one element constituing the material. |
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144 | const G4Element* anElement = SelectRandomAtom(aMaterial,theGamma,energy); |
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145 | |
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146 | // |
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147 | // Photo electron |
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148 | // |
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149 | |
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150 | // Select atomic shell |
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151 | G4int nShells = anElement->GetNbOfAtomicShells(); |
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152 | G4int i = 0; |
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153 | while ((i<nShells) && (energy<anElement->GetAtomicShell(i))) i++; |
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154 | |
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155 | // no shell available |
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156 | if (i == nShells) return; |
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157 | |
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158 | G4double bindingEnergy = anElement->GetAtomicShell(i); |
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159 | G4double ElecKineEnergy = energy - bindingEnergy; |
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160 | |
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161 | if (ElecKineEnergy > fminimalEnergy) |
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162 | { |
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163 | // direction of the photo electron |
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164 | // |
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165 | G4double cosTeta = ElecCosThetaDistribution(ElecKineEnergy); |
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166 | G4double sinTeta = sqrt(1.-cosTeta*cosTeta); |
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167 | G4double Phi = twopi * G4UniformRand(); |
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168 | G4double dirx = sinTeta*cos(Phi),diry = sinTeta*sin(Phi),dirz = cosTeta; |
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169 | G4ThreeVector ElecDirection(dirx,diry,dirz); |
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170 | ElecDirection.rotateUz(PhotonDirection); |
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171 | // |
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172 | G4DynamicParticle* aParticle = new G4DynamicParticle ( |
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173 | theElectron,ElecDirection, ElecKineEnergy); |
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174 | fvect->push_back(aParticle); |
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175 | } |
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176 | |
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177 | fParticleChange->SetProposedKineticEnergy(0.); |
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178 | fParticleChange->ProposeTrackStatus(fStopAndKill); |
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179 | fParticleChange->ProposeLocalEnergyDeposit(bindingEnergy); |
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180 | } |
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181 | |
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182 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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183 | |
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184 | G4double G4PEEffectModel::ElecCosThetaDistribution(G4double kineEnergy) |
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185 | { |
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186 | // Compute Theta distribution of the emitted electron, with respect to the |
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187 | // incident Gamma. |
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188 | // The Sauter-Gavrila distribution for the K-shell is used. |
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189 | // |
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190 | G4double costeta = 1.; |
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191 | G4double gamma = 1. + kineEnergy/electron_mass_c2; |
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192 | if (gamma > 5.) return costeta; |
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193 | G4double beta = sqrt(gamma*gamma-1.)/gamma; |
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194 | G4double b = 0.5*gamma*(gamma-1.)*(gamma-2); |
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195 | |
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196 | G4double rndm,term,greject,grejsup; |
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197 | if (gamma < 2.) grejsup = gamma*gamma*(1.+b-beta*b); |
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198 | else grejsup = gamma*gamma*(1.+b+beta*b); |
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199 | |
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200 | do { rndm = 1.-2*G4UniformRand(); |
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201 | costeta = (rndm+beta)/(rndm*beta+1.); |
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202 | term = 1.-beta*costeta; |
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203 | greject = (1.-costeta*costeta)*(1.+b*term)/(term*term); |
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204 | } while(greject < G4UniformRand()*grejsup); |
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205 | |
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206 | return costeta; |
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207 | } |
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208 | |
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209 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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