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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 | // $Id: G4eplusPolarizedAnnihilation.cc,v 1.6 2007/10/02 11:36:44 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-01-patch-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: G4eplusPolarizedAnnihilation |
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35 | // |
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36 | // Author: A. Schaelicke on base of Vladimir Ivanchenko / Michel Maire code |
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37 | // |
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38 | // Creation date: 02.07.2006 |
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39 | // |
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40 | // Modifications: |
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41 | // 26-07-06 modified cross section (P. Starovoitov) |
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42 | // 21-08-06 interface updated (A. Schaelicke) |
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43 | // 11-06-07, add PostStepGetPhysicalInteractionLength (A.Schalicke) |
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44 | // 02-10-07, enable AtRest (V.Ivanchenko) |
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45 | // |
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46 | // |
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47 | // Class Description: |
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48 | // |
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49 | // Polarized process of e+ annihilation into 2 gammas |
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50 | // |
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51 | |
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52 | // |
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53 | // ------------------------------------------------------------------- |
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54 | // |
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55 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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56 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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57 | |
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58 | #include "G4eplusPolarizedAnnihilation.hh" |
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59 | #include "G4MaterialCutsCouple.hh" |
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60 | #include "G4Gamma.hh" |
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61 | #include "G4PhysicsVector.hh" |
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62 | #include "G4PhysicsLogVector.hh" |
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63 | |
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64 | |
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65 | #include "G4PolarizedAnnihilationModel.hh" |
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66 | #include "G4PhysicsTableHelper.hh" |
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67 | #include "G4ProductionCutsTable.hh" |
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68 | #include "G4PolarizationManager.hh" |
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69 | #include "G4PolarizationHelper.hh" |
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70 | #include "G4StokesVector.hh" |
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71 | |
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72 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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73 | |
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74 | G4eplusPolarizedAnnihilation::G4eplusPolarizedAnnihilation(const G4String& name) |
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75 | : G4VEmProcess(name), isInitialised(false), |
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76 | theAsymmetryTable(NULL), |
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77 | theTransverseAsymmetryTable(NULL) |
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78 | { |
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79 | enableAtRestDoIt = true; |
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80 | } |
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81 | |
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82 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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83 | |
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84 | G4eplusPolarizedAnnihilation::~G4eplusPolarizedAnnihilation() |
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85 | { |
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86 | if (theAsymmetryTable) { |
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87 | theAsymmetryTable->clearAndDestroy(); |
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88 | delete theAsymmetryTable; |
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89 | } |
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90 | if (theTransverseAsymmetryTable) { |
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91 | theTransverseAsymmetryTable->clearAndDestroy(); |
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92 | delete theTransverseAsymmetryTable; |
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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 G4eplusPolarizedAnnihilation::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 | // SetVerboseLevel(3); |
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103 | SetBuildTableFlag(true); |
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104 | SetStartFromNullFlag(false); |
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105 | SetSecondaryParticle(G4Gamma::Gamma()); |
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106 | G4double emin = 0.1*keV; |
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107 | G4double emax = 100.*TeV; |
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108 | SetLambdaBinning(120); |
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109 | SetMinKinEnergy(emin); |
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110 | SetMaxKinEnergy(emax); |
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111 | emModel = new G4PolarizedAnnihilationModel(); |
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112 | emModel->SetLowEnergyLimit(emin); |
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113 | emModel->SetHighEnergyLimit(emax); |
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114 | AddEmModel(1, emModel); |
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115 | } |
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116 | } |
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117 | |
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118 | |
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119 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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120 | |
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121 | // for polarization |
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122 | |
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123 | G4double G4eplusPolarizedAnnihilation::GetMeanFreePath(const G4Track& track, |
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124 | G4double previousStepSize, |
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125 | G4ForceCondition* condition) |
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126 | { |
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127 | G4double mfp = G4VEmProcess::GetMeanFreePath(track, previousStepSize, condition); |
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128 | |
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129 | if (theAsymmetryTable) { |
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130 | |
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131 | G4Material* aMaterial = track.GetMaterial(); |
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132 | G4VPhysicalVolume* aPVolume = track.GetVolume(); |
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133 | G4LogicalVolume* aLVolume = aPVolume->GetLogicalVolume(); |
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134 | |
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135 | // G4Material* bMaterial = aLVolume->GetMaterial(); |
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136 | G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance(); |
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137 | |
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138 | const G4bool volumeIsPolarized = polarizationManger->IsPolarized(aLVolume); |
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139 | G4StokesVector electronPolarization = polarizationManger->GetVolumePolarization(aLVolume); |
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140 | |
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141 | if (!volumeIsPolarized || mfp == DBL_MAX) return mfp; |
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142 | |
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143 | // *** get asymmetry, if target is polarized *** |
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144 | const G4DynamicParticle* aDynamicPositron = track.GetDynamicParticle(); |
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145 | const G4double positronEnergy = aDynamicPositron->GetKineticEnergy(); |
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146 | const G4StokesVector positronPolarization = track.GetPolarization(); |
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147 | const G4ParticleMomentum positronDirection0 = aDynamicPositron->GetMomentumDirection(); |
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148 | |
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149 | if (verboseLevel>=2) { |
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150 | |
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151 | G4cout << " Mom " << positronDirection0 << G4endl; |
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152 | G4cout << " Polarization " << positronPolarization << G4endl; |
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153 | G4cout << " MaterialPol. " << electronPolarization << G4endl; |
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154 | G4cout << " Phys. Volume " << aPVolume->GetName() << G4endl; |
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155 | G4cout << " Log. Volume " << aLVolume->GetName() << G4endl; |
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156 | G4cout << " Material " << aMaterial << G4endl; |
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157 | } |
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158 | |
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159 | G4bool isOutRange; |
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160 | G4int idx= CurrentMaterialCutsCoupleIndex(); |
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161 | G4double lAsymmetry = (*theAsymmetryTable)(idx)-> |
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162 | GetValue(positronEnergy, isOutRange); |
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163 | G4double tAsymmetry = (*theTransverseAsymmetryTable)(idx)-> |
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164 | GetValue(positronEnergy, isOutRange); |
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165 | |
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166 | G4double polZZ = positronPolarization.z()* |
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167 | electronPolarization*positronDirection0; |
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168 | G4double polXX = positronPolarization.x()* |
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169 | electronPolarization*G4PolarizationHelper::GetParticleFrameX(positronDirection0); |
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170 | G4double polYY = positronPolarization.y()* |
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171 | electronPolarization*G4PolarizationHelper::GetParticleFrameY(positronDirection0); |
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172 | |
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173 | G4double impact = 1. + polZZ*lAsymmetry + (polXX + polYY)*tAsymmetry; |
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174 | |
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175 | mfp *= 1. / impact; |
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176 | |
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177 | if (verboseLevel>=2) { |
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178 | G4cout << " MeanFreePath: " << mfp / mm << " mm " << G4endl; |
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179 | G4cout << " Asymmetry: " << lAsymmetry << ", " << tAsymmetry << G4endl; |
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180 | G4cout << " PolProduct: " << polXX << ", " << polYY << ", " << polZZ << G4endl; |
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181 | } |
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182 | } |
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183 | |
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184 | return mfp; |
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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 G4eplusPolarizedAnnihilation::PostStepGetPhysicalInteractionLength( |
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190 | const G4Track& track, |
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191 | G4double previousStepSize, |
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192 | G4ForceCondition* condition) |
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193 | { |
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194 | G4double mfp = G4VEmProcess::PostStepGetPhysicalInteractionLength(track, previousStepSize, condition); |
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195 | |
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196 | if (theAsymmetryTable) { |
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197 | |
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198 | G4Material* aMaterial = track.GetMaterial(); |
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199 | G4VPhysicalVolume* aPVolume = track.GetVolume(); |
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200 | G4LogicalVolume* aLVolume = aPVolume->GetLogicalVolume(); |
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201 | |
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202 | // G4Material* bMaterial = aLVolume->GetMaterial(); |
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203 | G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance(); |
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204 | |
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205 | const G4bool volumeIsPolarized = polarizationManger->IsPolarized(aLVolume); |
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206 | G4StokesVector electronPolarization = polarizationManger->GetVolumePolarization(aLVolume); |
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207 | |
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208 | if (!volumeIsPolarized || mfp == DBL_MAX) return mfp; |
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209 | |
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210 | // *** get asymmetry, if target is polarized *** |
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211 | const G4DynamicParticle* aDynamicPositron = track.GetDynamicParticle(); |
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212 | const G4double positronEnergy = aDynamicPositron->GetKineticEnergy(); |
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213 | const G4StokesVector positronPolarization = track.GetPolarization(); |
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214 | const G4ParticleMomentum positronDirection0 = aDynamicPositron->GetMomentumDirection(); |
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215 | |
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216 | if (verboseLevel>=2) { |
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217 | |
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218 | G4cout << " Mom " << positronDirection0 << G4endl; |
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219 | G4cout << " Polarization " << positronPolarization << G4endl; |
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220 | G4cout << " MaterialPol. " << electronPolarization << G4endl; |
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221 | G4cout << " Phys. Volume " << aPVolume->GetName() << G4endl; |
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222 | G4cout << " Log. Volume " << aLVolume->GetName() << G4endl; |
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223 | G4cout << " Material " << aMaterial << G4endl; |
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224 | } |
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225 | |
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226 | G4bool isOutRange; |
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227 | G4int idx= CurrentMaterialCutsCoupleIndex(); |
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228 | G4double lAsymmetry = (*theAsymmetryTable)(idx)-> |
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229 | GetValue(positronEnergy, isOutRange); |
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230 | G4double tAsymmetry = (*theTransverseAsymmetryTable)(idx)-> |
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231 | GetValue(positronEnergy, isOutRange); |
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232 | |
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233 | G4double polZZ = positronPolarization.z()* |
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234 | electronPolarization*positronDirection0; |
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235 | G4double polXX = positronPolarization.x()* |
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236 | electronPolarization*G4PolarizationHelper::GetParticleFrameX(positronDirection0); |
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237 | G4double polYY = positronPolarization.y()* |
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238 | electronPolarization*G4PolarizationHelper::GetParticleFrameY(positronDirection0); |
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239 | |
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240 | G4double impact = 1. + polZZ*lAsymmetry + (polXX + polYY)*tAsymmetry; |
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241 | |
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242 | mfp *= 1. / impact; |
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243 | |
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244 | if (verboseLevel>=2) { |
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245 | G4cout << " MeanFreePath: " << mfp / mm << " mm " << G4endl; |
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246 | G4cout << " Asymmetry: " << lAsymmetry << ", " << tAsymmetry << G4endl; |
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247 | G4cout << " PolProduct: " << polXX << ", " << polYY << ", " << polZZ << G4endl; |
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248 | } |
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249 | } |
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250 | |
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251 | return mfp; |
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252 | } |
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253 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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254 | |
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255 | void G4eplusPolarizedAnnihilation::BuildPhysicsTable(const G4ParticleDefinition& pd) |
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256 | { |
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257 | G4VEmProcess::BuildPhysicsTable(pd); |
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258 | BuildAsymmetryTable(pd); |
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259 | } |
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260 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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261 | |
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262 | void G4eplusPolarizedAnnihilation::PreparePhysicsTable(const G4ParticleDefinition& pd) |
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263 | { |
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264 | G4VEmProcess::PreparePhysicsTable(pd); |
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265 | theAsymmetryTable = G4PhysicsTableHelper::PreparePhysicsTable(theAsymmetryTable); |
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266 | theTransverseAsymmetryTable = G4PhysicsTableHelper::PreparePhysicsTable(theTransverseAsymmetryTable); |
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267 | } |
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268 | |
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269 | void G4eplusPolarizedAnnihilation::BuildAsymmetryTable(const G4ParticleDefinition& part) |
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270 | { |
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271 | // Access to materials |
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272 | const G4ProductionCutsTable* theCoupleTable= |
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273 | G4ProductionCutsTable::GetProductionCutsTable(); |
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274 | size_t numOfCouples = theCoupleTable->GetTableSize(); |
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275 | G4cout<<" annih-numOfCouples="<<numOfCouples<<"\n"; |
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276 | for(size_t i=0; i<numOfCouples; ++i) { |
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277 | G4cout<<"annih- "<<i<<"/"<<numOfCouples<<"\n"; |
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278 | if (!theAsymmetryTable) break; |
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279 | G4cout<<"annih- "<<theAsymmetryTable->GetFlag(i)<<"\n"; |
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280 | if (theAsymmetryTable->GetFlag(i)) { |
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281 | G4cout<<" building pol-annih ... \n"; |
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282 | |
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283 | // create physics vector and fill it |
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284 | const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(i); |
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285 | |
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286 | // use same parameters as for lambda |
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287 | G4PhysicsVector* aVector = LambdaPhysicsVector(couple); |
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288 | G4PhysicsVector* tVector = LambdaPhysicsVector(couple); |
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289 | |
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290 | for (G4int j = 0 ; j < LambdaBinning() ; ++j ) { |
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291 | G4double lowEdgeEnergy = aVector->GetLowEdgeEnergy(j); |
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292 | G4double tasm=0.; |
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293 | G4double asym = ComputeAsymmetry(lowEdgeEnergy, couple, part, 0., tasm); |
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294 | aVector->PutValue(j,asym); |
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295 | tVector->PutValue(j,tasm); |
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296 | } |
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297 | |
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298 | G4PhysicsTableHelper::SetPhysicsVector(theAsymmetryTable, i, aVector); |
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299 | G4PhysicsTableHelper::SetPhysicsVector(theTransverseAsymmetryTable, i, tVector); |
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300 | } |
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301 | } |
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302 | |
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303 | } |
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304 | |
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305 | |
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306 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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307 | |
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308 | G4double G4eplusPolarizedAnnihilation::ComputeAsymmetry(G4double energy, |
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309 | const G4MaterialCutsCouple* couple, |
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310 | const G4ParticleDefinition& aParticle, |
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311 | G4double cut, |
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312 | G4double &tAsymmetry) |
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313 | { |
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314 | G4double lAsymmetry = 0.0; |
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315 | tAsymmetry = 0.0; |
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316 | |
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317 | // calculate polarized cross section |
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318 | theTargetPolarization=G4ThreeVector(0.,0.,1.); |
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319 | emModel->SetTargetPolarization(theTargetPolarization); |
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320 | emModel->SetBeamPolarization(theTargetPolarization); |
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321 | G4double sigma2=emModel->CrossSection(couple,&aParticle,energy,cut,energy); |
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322 | |
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323 | // calculate transversely polarized cross section |
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324 | theTargetPolarization=G4ThreeVector(1.,0.,0.); |
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325 | emModel->SetTargetPolarization(theTargetPolarization); |
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326 | emModel->SetBeamPolarization(theTargetPolarization); |
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327 | G4double sigma3=emModel->CrossSection(couple,&aParticle,energy,cut,energy); |
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328 | |
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329 | // calculate unpolarized cross section |
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330 | theTargetPolarization=G4ThreeVector(); |
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331 | emModel->SetTargetPolarization(theTargetPolarization); |
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332 | emModel->SetBeamPolarization(theTargetPolarization); |
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333 | G4double sigma0=emModel->CrossSection(couple,&aParticle,energy,cut,energy); |
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334 | |
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335 | // determine assymmetries |
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336 | if (sigma0>0.) { |
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337 | lAsymmetry=sigma2/sigma0-1.; |
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338 | tAsymmetry=sigma3/sigma0-1.; |
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339 | } |
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340 | return lAsymmetry; |
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341 | |
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342 | } |
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343 | |
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344 | |
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345 | |
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346 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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347 | |
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348 | void G4eplusPolarizedAnnihilation::PrintInfo() |
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349 | { |
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350 | G4cout << " Polarized model for annihilation into 2 photons" |
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351 | << G4endl; |
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352 | } |
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353 | |
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354 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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355 | |
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356 | G4VParticleChange* G4eplusPolarizedAnnihilation::AtRestDoIt(const G4Track& aTrack, |
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357 | const G4Step& ) |
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358 | // |
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359 | // Performs the e+ e- annihilation when both particles are assumed at rest. |
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360 | // It generates two back to back photons with energy = electron_mass. |
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361 | // The angular distribution is isotropic. |
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362 | // GEANT4 internal units |
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363 | // |
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364 | // Note : Effects due to binding of atomic electrons are negliged. |
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365 | { |
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366 | fParticleChange.InitializeForPostStep(aTrack); |
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367 | |
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368 | fParticleChange.SetNumberOfSecondaries(2); |
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369 | |
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370 | G4double cosTeta = 2.*G4UniformRand()-1. , sinTeta = std::sqrt(1.-cosTeta*cosTeta); |
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371 | G4double phi = twopi * G4UniformRand(); |
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372 | G4ThreeVector direction (sinTeta*std::cos(phi), sinTeta*std::sin(phi), cosTeta); |
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373 | fParticleChange.AddSecondary( new G4DynamicParticle (G4Gamma::Gamma(), |
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374 | direction, electron_mass_c2) ); |
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375 | fParticleChange.AddSecondary( new G4DynamicParticle (G4Gamma::Gamma(), |
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376 | -direction, electron_mass_c2) ); |
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377 | // Kill the incident positron |
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378 | // |
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379 | fParticleChange.ProposeTrackStatus(fStopAndKill); |
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380 | return &fParticleChange; |
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381 | } |
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382 | |
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383 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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