1 | // |
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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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18 | // * This code implementation is the result of the scientific and * |
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23 | // * acceptance of all terms of the Geant4 Software license. * |
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24 | // ******************************************************************** |
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25 | // |
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26 | // |
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27 | // $Id: G4PolarizedCompton.cc,v 1.9 2008/10/30 22:34:23 schaelic Exp $ |
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28 | // GEANT4 tag $Name: geant4-09-02 $ |
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29 | // |
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30 | // |
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31 | // File name: G4PolarizedCompton |
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32 | // |
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33 | // Author: Andreas Schaelicke |
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34 | // based on code by Michel Maire / Vladimir IVANTCHENKO |
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35 | // Class description |
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36 | // |
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37 | // modified version respecting media and beam polarization |
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38 | // using the stokes formalism |
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39 | // |
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40 | // Creation date: 01.05.2005 |
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41 | // |
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42 | // Modifications: |
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43 | // |
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44 | // 01-01-05, include polarization description (A.Stahl) |
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45 | // 01-01-05, create asymmetry table and determine interactionlength (A.Stahl) |
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46 | // 01-05-05, update handling of media polarization (A.Schalicke) |
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47 | // 01-05-05, update polarized differential cross section (A.Schalicke) |
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48 | // 20-05-05, added polarization transfer (A.Schalicke) |
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49 | // 10-06-05, transformation between different reference frames (A.Schalicke) |
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50 | // 17-10-05, correct reference frame dependence in GetMeanFreePath (A.Schalicke) |
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51 | // 26-07-06, cross section recalculated (P.Starovoitov) |
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52 | // 09-08-06, make it work under current geant4 release (A.Schalicke) |
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53 | // 11-06-07, add PostStepGetPhysicalInteractionLength (A.Schalicke) |
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54 | // ----------------------------------------------------------------------------- |
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55 | |
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56 | |
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57 | #include "G4PolarizedCompton.hh" |
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58 | #include "G4Electron.hh" |
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59 | |
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60 | #include "G4StokesVector.hh" |
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61 | #include "G4PolarizationManager.hh" |
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62 | #include "G4PolarizedComptonModel.hh" |
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63 | #include "G4ProductionCutsTable.hh" |
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64 | #include "G4PhysicsTableHelper.hh" |
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65 | #include "G4KleinNishinaCompton.hh" |
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66 | #include "G4PolarizedComptonModel.hh" |
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67 | |
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68 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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69 | |
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70 | G4PolarizedCompton::G4PolarizedCompton(const G4String& processName, |
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71 | G4ProcessType type): |
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72 | G4VEmProcess (processName, type), |
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73 | buildAsymmetryTable(true), |
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74 | useAsymmetryTable(true), |
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75 | isInitialised(false), |
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76 | selectedModel(0), |
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77 | mType(10), |
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78 | theAsymmetryTable(NULL) |
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79 | { |
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80 | SetLambdaBinning(90); |
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81 | SetMinKinEnergy(0.1*keV); |
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82 | SetMaxKinEnergy(100.0*GeV); |
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83 | SetProcessSubType(fComptonScattering); |
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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 | G4PolarizedCompton::~G4PolarizedCompton() |
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89 | { |
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90 | if (theAsymmetryTable) { |
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91 | theAsymmetryTable->clearAndDestroy(); |
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92 | delete theAsymmetryTable; |
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93 | } |
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94 | } |
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95 | |
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96 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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97 | |
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98 | void G4PolarizedCompton::InitialiseProcess(const G4ParticleDefinition*) |
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99 | { |
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100 | if(!isInitialised) { |
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101 | isInitialised = true; |
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102 | SetBuildTableFlag(true); |
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103 | SetSecondaryParticle(G4Electron::Electron()); |
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104 | G4double emin = MinKinEnergy(); |
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105 | G4double emax = MaxKinEnergy(); |
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106 | emModel = new G4PolarizedComptonModel(); |
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107 | if(0 == mType) selectedModel = new G4KleinNishinaCompton(); |
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108 | else if(10 == mType) selectedModel = emModel; |
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109 | selectedModel->SetLowEnergyLimit(emin); |
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110 | selectedModel->SetHighEnergyLimit(emax); |
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111 | AddEmModel(1, selectedModel); |
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112 | } |
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113 | } |
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114 | |
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115 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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116 | |
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117 | void G4PolarizedCompton::PrintInfo() |
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118 | { |
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119 | G4cout << " Total cross sections has a good parametrisation" |
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120 | << " from 10 KeV to (100/Z) GeV" |
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121 | << "\n Sampling according " << selectedModel->GetName() << " model" |
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122 | << G4endl; |
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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 G4PolarizedCompton::SetModel(const G4String& s) |
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128 | { |
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129 | if(s == "Klein-Nishina") mType = 0; |
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130 | if(s == "Polarized-Compton") mType = 10; |
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131 | } |
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132 | |
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133 | |
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134 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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135 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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136 | |
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137 | |
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138 | |
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139 | G4double G4PolarizedCompton::GetMeanFreePath( |
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140 | const G4Track& aTrack, |
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141 | G4double previousStepSize, |
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142 | G4ForceCondition* condition) |
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143 | { |
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144 | // *** get unploarised mean free path from lambda table *** |
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145 | G4double mfp = G4VEmProcess::GetMeanFreePath(aTrack, previousStepSize, condition); |
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146 | |
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147 | |
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148 | if (theAsymmetryTable && useAsymmetryTable) { |
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149 | // *** get asymmetry, if target is polarized *** |
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150 | const G4DynamicParticle* aDynamicGamma = aTrack.GetDynamicParticle(); |
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151 | const G4double GammaEnergy = aDynamicGamma->GetKineticEnergy(); |
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152 | const G4StokesVector GammaPolarization = aTrack.GetPolarization(); |
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153 | const G4ParticleMomentum GammaDirection0 = aDynamicGamma->GetMomentumDirection(); |
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154 | |
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155 | G4Material* aMaterial = aTrack.GetMaterial(); |
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156 | G4VPhysicalVolume* aPVolume = aTrack.GetVolume(); |
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157 | G4LogicalVolume* aLVolume = aPVolume->GetLogicalVolume(); |
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158 | |
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159 | // G4Material* bMaterial = aLVolume->GetMaterial(); |
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160 | G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance(); |
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161 | |
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162 | const G4bool VolumeIsPolarized = polarizationManger->IsPolarized(aLVolume); |
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163 | G4StokesVector ElectronPolarization = polarizationManger->GetVolumePolarization(aLVolume); |
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164 | |
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165 | if (!VolumeIsPolarized || mfp == DBL_MAX) return mfp; |
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166 | |
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167 | if (verboseLevel>=2) { |
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168 | |
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169 | G4cout << " Mom " << GammaDirection0 << G4endl; |
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170 | G4cout << " Polarization " << GammaPolarization << G4endl; |
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171 | G4cout << " MaterialPol. " << ElectronPolarization << G4endl; |
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172 | G4cout << " Phys. Volume " << aPVolume->GetName() << G4endl; |
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173 | G4cout << " Log. Volume " << aLVolume->GetName() << G4endl; |
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174 | G4cout << " Material " << aMaterial << G4endl; |
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175 | } |
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176 | |
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177 | G4int midx= CurrentMaterialCutsCoupleIndex(); |
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178 | G4PhysicsVector * aVector=(*theAsymmetryTable)(midx); |
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179 | |
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180 | G4double asymmetry=0; |
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181 | if (aVector) { |
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182 | G4bool isOutRange; |
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183 | asymmetry = aVector->GetValue(GammaEnergy, isOutRange); |
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184 | } else { |
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185 | G4cout << " MaterialIndex " << midx << " is out of range \n"; |
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186 | asymmetry=0; |
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187 | } |
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188 | |
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189 | // we have to determine angle between particle motion |
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190 | // and target polarisation here |
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191 | // circ pol * Vec(ElectronPol)*Vec(PhotonMomentum) |
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192 | // both vectors in global reference frame |
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193 | |
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194 | G4double pol=ElectronPolarization*GammaDirection0; |
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195 | |
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196 | G4double polProduct = GammaPolarization.p3() * pol; |
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197 | mfp *= 1. / ( 1. + polProduct * asymmetry ); |
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198 | |
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199 | if (verboseLevel>=2) { |
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200 | G4cout << " MeanFreePath: " << mfp / mm << " mm " << G4endl; |
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201 | G4cout << " Asymmetry: " << asymmetry << G4endl; |
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202 | G4cout << " PolProduct: " << polProduct << G4endl; |
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203 | } |
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204 | } |
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205 | |
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206 | return mfp; |
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207 | } |
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208 | |
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209 | G4double G4PolarizedCompton::PostStepGetPhysicalInteractionLength( |
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210 | const G4Track& aTrack, |
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211 | G4double previousStepSize, |
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212 | G4ForceCondition* condition) |
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213 | { |
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214 | // *** get unploarised mean free path from lambda table *** |
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215 | G4double mfp = G4VEmProcess::PostStepGetPhysicalInteractionLength(aTrack, previousStepSize, condition); |
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216 | |
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217 | |
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218 | if (theAsymmetryTable && useAsymmetryTable) { |
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219 | // *** get asymmetry, if target is polarized *** |
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220 | const G4DynamicParticle* aDynamicGamma = aTrack.GetDynamicParticle(); |
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221 | const G4double GammaEnergy = aDynamicGamma->GetKineticEnergy(); |
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222 | const G4StokesVector GammaPolarization = aTrack.GetPolarization(); |
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223 | const G4ParticleMomentum GammaDirection0 = aDynamicGamma->GetMomentumDirection(); |
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224 | |
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225 | G4Material* aMaterial = aTrack.GetMaterial(); |
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226 | G4VPhysicalVolume* aPVolume = aTrack.GetVolume(); |
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227 | G4LogicalVolume* aLVolume = aPVolume->GetLogicalVolume(); |
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228 | |
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229 | // G4Material* bMaterial = aLVolume->GetMaterial(); |
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230 | G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance(); |
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231 | |
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232 | const G4bool VolumeIsPolarized = polarizationManger->IsPolarized(aLVolume); |
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233 | G4StokesVector ElectronPolarization = polarizationManger->GetVolumePolarization(aLVolume); |
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234 | |
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235 | if (!VolumeIsPolarized || mfp == DBL_MAX) return mfp; |
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236 | |
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237 | if (verboseLevel>=2) { |
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238 | |
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239 | G4cout << " Mom " << GammaDirection0 << G4endl; |
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240 | G4cout << " Polarization " << GammaPolarization << G4endl; |
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241 | G4cout << " MaterialPol. " << ElectronPolarization << G4endl; |
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242 | G4cout << " Phys. Volume " << aPVolume->GetName() << G4endl; |
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243 | G4cout << " Log. Volume " << aLVolume->GetName() << G4endl; |
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244 | G4cout << " Material " << aMaterial << G4endl; |
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245 | } |
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246 | |
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247 | G4int midx= CurrentMaterialCutsCoupleIndex(); |
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248 | G4PhysicsVector * aVector=(*theAsymmetryTable)(midx); |
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249 | |
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250 | G4double asymmetry=0; |
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251 | if (aVector) { |
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252 | G4bool isOutRange; |
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253 | asymmetry = aVector->GetValue(GammaEnergy, isOutRange); |
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254 | } else { |
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255 | G4cout << " MaterialIndex " << midx << " is out of range \n"; |
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256 | asymmetry=0; |
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257 | } |
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258 | |
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259 | // we have to determine angle between particle motion |
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260 | // and target polarisation here |
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261 | // circ pol * Vec(ElectronPol)*Vec(PhotonMomentum) |
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262 | // both vectors in global reference frame |
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263 | |
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264 | G4double pol=ElectronPolarization*GammaDirection0; |
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265 | |
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266 | G4double polProduct = GammaPolarization.p3() * pol; |
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267 | mfp *= 1. / ( 1. + polProduct * asymmetry ); |
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268 | |
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269 | if (verboseLevel>=2) { |
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270 | G4cout << " MeanFreePath: " << mfp / mm << " mm " << G4endl; |
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271 | G4cout << " Asymmetry: " << asymmetry << G4endl; |
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272 | G4cout << " PolProduct: " << polProduct << G4endl; |
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273 | } |
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274 | } |
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275 | |
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276 | return mfp; |
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277 | } |
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278 | |
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279 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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280 | |
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281 | void G4PolarizedCompton::PreparePhysicsTable(const G4ParticleDefinition& part) |
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282 | { |
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283 | G4VEmProcess::PreparePhysicsTable(part); |
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284 | if(buildAsymmetryTable) |
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285 | theAsymmetryTable = G4PhysicsTableHelper::PreparePhysicsTable(theAsymmetryTable); |
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286 | } |
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287 | |
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288 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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289 | |
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290 | |
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291 | void G4PolarizedCompton::BuildPhysicsTable(const G4ParticleDefinition& part) |
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292 | { |
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293 | // *** build (unpolarized) cross section tables (Lambda) |
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294 | G4VEmProcess::BuildPhysicsTable(part); |
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295 | if(buildAsymmetryTable) |
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296 | BuildAsymmetryTable(part); |
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297 | } |
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298 | |
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299 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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300 | |
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301 | |
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302 | void G4PolarizedCompton::BuildAsymmetryTable(const G4ParticleDefinition& part) |
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303 | { |
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304 | // Access to materials |
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305 | const G4ProductionCutsTable* theCoupleTable= |
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306 | G4ProductionCutsTable::GetProductionCutsTable(); |
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307 | size_t numOfCouples = theCoupleTable->GetTableSize(); |
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308 | for(size_t i=0; i<numOfCouples; ++i) { |
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309 | if (!theAsymmetryTable) break; |
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310 | if (theAsymmetryTable->GetFlag(i)) { |
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311 | |
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312 | // create physics vector and fill it |
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313 | const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(i); |
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314 | // use same parameters as for lambda |
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315 | G4PhysicsVector* aVector = LambdaPhysicsVector(couple); |
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316 | // modelManager->FillLambdaVector(aVector, couple, startFromNull); |
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317 | |
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318 | for (G4int j = 0 ; j < LambdaBinning() ; ++j ) { |
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319 | G4double lowEdgeEnergy = aVector->GetLowEdgeEnergy(j); |
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320 | G4double tasm=0.; |
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321 | G4double asym = ComputeAsymmetry(lowEdgeEnergy, couple, part, 0., tasm); |
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322 | aVector->PutValue(j,asym); |
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323 | } |
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324 | |
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325 | G4PhysicsTableHelper::SetPhysicsVector(theAsymmetryTable, i, aVector); |
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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 | |
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331 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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332 | |
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333 | |
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334 | G4double G4PolarizedCompton::ComputeAsymmetry(G4double energy, |
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335 | const G4MaterialCutsCouple* couple, |
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336 | const G4ParticleDefinition& aParticle, |
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337 | G4double cut, |
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338 | G4double & tAsymmetry) |
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339 | { |
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340 | G4double lAsymmetry = 0.0; |
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341 | tAsymmetry=0; |
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342 | |
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343 | // |
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344 | // calculate polarized cross section |
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345 | // |
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346 | G4ThreeVector thePolarization=G4ThreeVector(0.,0.,1.); |
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347 | emModel->SetTargetPolarization(thePolarization); |
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348 | emModel->SetBeamPolarization(thePolarization); |
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349 | G4double sigma2=emModel->CrossSection(couple,&aParticle,energy,cut,energy); |
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350 | |
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351 | // |
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352 | // calculate unpolarized cross section |
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353 | // |
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354 | thePolarization=G4ThreeVector(); |
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355 | emModel->SetTargetPolarization(thePolarization); |
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356 | emModel->SetBeamPolarization(thePolarization); |
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357 | G4double sigma0=emModel->CrossSection(couple,&aParticle,energy,cut,energy); |
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358 | |
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359 | // determine assymmetries |
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360 | if (sigma0>0.) { |
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361 | lAsymmetry=sigma2/sigma0-1.; |
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362 | } |
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363 | return lAsymmetry; |
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364 | } |
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365 | |
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366 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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