1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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9 | // * include a list of copyright holders. * |
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10 | // * * |
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11 | // * Neither the authors of this software system, nor their employing * |
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12 | // * institutes,nor the agencies providing financial support for this * |
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13 | // * work make any representation or warranty, express or implied, * |
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14 | // * regarding this software system or assume any liability for its * |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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16 | // * for the full disclaimer and the limitation of liability. * |
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17 | // * * |
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18 | // * This code implementation is the result of the scientific and * |
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19 | // * technical work of the GEANT4 collaboration. * |
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20 | // * By using, copying, modifying or distributing the software (or * |
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21 | // * any work based on the software) you agree to acknowledge its * |
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22 | // * use in resulting scientific publications, and indicate your * |
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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: G4VLowEnergyDiscretePhotonProcess.cc,v 1.5 2006/06/29 19:41:44 gunter Exp $ |
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27 | // GEANT4 tag $Name: $ |
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28 | // |
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29 | // -------------------------------------------------------------- |
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30 | // |
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31 | // File name: G4VLowEnergyDiscretePhotonProcess.cc |
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32 | // |
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33 | // Author: Capra Riccardo |
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34 | // |
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35 | // Creation date: May 2005 |
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36 | // |
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37 | // History: |
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38 | // ----------- |
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39 | // 02 May 2005 R. Capra 1st implementation |
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40 | // |
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41 | //---------------------------------------------------------------- |
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42 | |
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43 | |
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44 | |
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45 | #include "G4VLowEnergyDiscretePhotonProcess.hh" |
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46 | |
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47 | #include "G4String.hh" |
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48 | #include "G4CrossSectionHandler.hh" |
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49 | #include "G4CompositeEMDataSet.hh" |
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50 | #include "G4Gamma.hh" |
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51 | #include "G4Track.hh" |
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52 | #include "G4DynamicParticle.hh" |
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53 | #include "G4ThreeVector.hh" |
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54 | #include "Randomize.hh" // G4UniformRand |
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55 | |
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56 | G4VLowEnergyDiscretePhotonProcess :: G4VLowEnergyDiscretePhotonProcess(const G4String& processName, |
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57 | const G4String& aCrossSectionFileName, |
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58 | const G4String& aScatterFileName, |
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59 | G4VDataSetAlgorithm* aScatterInterpolation, |
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60 | G4double aLowEnergyLimit, |
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61 | G4double aHighEnergyLimit) |
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62 | : |
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63 | G4VLowEnergyTestableDiscreteProcess(processName), |
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64 | lowEnergyLimit(aLowEnergyLimit), |
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65 | highEnergyLimit(aHighEnergyLimit), |
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66 | crossSectionFileName(aCrossSectionFileName), |
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67 | meanFreePathTable(0) |
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68 | { |
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69 | crossSectionHandler = new G4CrossSectionHandler(); |
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70 | scatterFunctionData = new G4CompositeEMDataSet(aScatterInterpolation, 1., 1.); |
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71 | scatterFunctionData->LoadData(aScatterFileName); |
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72 | |
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73 | if (verboseLevel > 0) |
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74 | { |
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75 | G4cout << GetProcessName() << " is created " << G4endl |
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76 | << "Energy range: " |
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77 | << lowEnergyLimit / keV << " keV - " |
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78 | << highEnergyLimit / GeV << " GeV" |
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79 | << G4endl; |
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80 | } |
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81 | } |
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82 | |
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83 | |
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84 | |
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85 | G4VLowEnergyDiscretePhotonProcess::~G4VLowEnergyDiscretePhotonProcess(void) |
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86 | { |
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87 | if (meanFreePathTable) |
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88 | delete meanFreePathTable; |
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89 | |
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90 | delete crossSectionHandler; |
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91 | delete scatterFunctionData; |
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92 | } |
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93 | |
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94 | |
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95 | |
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96 | |
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97 | |
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98 | G4bool G4VLowEnergyDiscretePhotonProcess::IsApplicable(const G4ParticleDefinition& particleDefinition) |
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99 | { |
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100 | return (&particleDefinition)==G4Gamma::Gamma(); |
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101 | } |
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102 | |
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103 | |
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104 | |
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105 | void G4VLowEnergyDiscretePhotonProcess::BuildPhysicsTable(const G4ParticleDefinition& /*photon*/) |
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106 | { |
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107 | crossSectionHandler->Clear(); |
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108 | crossSectionHandler->LoadData(crossSectionFileName); |
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109 | |
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110 | if (meanFreePathTable) |
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111 | delete meanFreePathTable; |
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112 | meanFreePathTable=crossSectionHandler->BuildMeanFreePathForMaterials(); |
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113 | } |
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114 | |
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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 | G4double G4VLowEnergyDiscretePhotonProcess::GetMeanFreePath(const G4Track& aTrack, G4double /*previousStepSize*/, G4ForceCondition* /*condition*/) |
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120 | { |
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121 | G4double photonEnergy; |
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122 | photonEnergy = aTrack.GetDynamicParticle()->GetKineticEnergy(); |
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123 | |
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124 | if (photonEnergy < lowEnergyLimit) |
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125 | return DBL_MAX; |
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126 | |
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127 | if (photonEnergy > highEnergyLimit) |
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128 | photonEnergy=highEnergyLimit; |
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129 | |
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130 | size_t materialIndex; |
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131 | materialIndex = aTrack.GetMaterialCutsCouple()->GetIndex(); |
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132 | |
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133 | return meanFreePathTable->FindValue(photonEnergy, materialIndex); |
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134 | } |
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135 | |
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136 | |
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137 | |
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138 | |
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139 | |
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140 | G4ThreeVector G4VLowEnergyDiscretePhotonProcess::GetPhotonPolarization(const G4DynamicParticle& photon) |
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141 | { |
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142 | G4ThreeVector photonMomentumDirection; |
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143 | G4ThreeVector photonPolarization; |
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144 | |
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145 | photonPolarization = photon.GetPolarization(); |
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146 | photonMomentumDirection = photon.GetMomentumDirection(); |
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147 | |
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148 | if ((!photonPolarization.isOrthogonal(photonMomentumDirection, 1e-6)) || photonPolarization.mag()==0.) |
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149 | { |
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150 | // if |photonPolarization|==0. or |photonPolarization * photonDirection0| > 1e-6 * |photonPolarization ^ photonDirection0| |
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151 | // then polarization is choosen randomly. |
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152 | |
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153 | G4ThreeVector e1(photonMomentumDirection.orthogonal().unit()); |
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154 | G4ThreeVector e2(photonMomentumDirection.cross(e1).unit()); |
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155 | |
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156 | G4double angle(G4UniformRand() * twopi); |
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157 | |
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158 | e1*=std::cos(angle); |
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159 | e2*=std::sin(angle); |
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160 | |
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161 | photonPolarization=e1+e2; |
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162 | } |
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163 | else if (photonPolarization.howOrthogonal(photonMomentumDirection) != 0.) |
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164 | { |
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165 | // if |photonPolarization * photonDirection0| != 0. |
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166 | // then polarization is made orthonormal; |
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167 | |
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168 | photonPolarization=photonPolarization.perpPart(photonMomentumDirection); |
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169 | } |
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170 | |
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171 | return photonPolarization.unit(); |
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172 | } |
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