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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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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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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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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 | // G4IonCoulombScatteringModel.cc |
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27 | // ------------------------------------------------------------------- |
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28 | // |
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29 | // GEANT4 Class header file |
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30 | // |
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31 | // File name: G4IonCoulombScatteringModel |
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32 | // |
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33 | // Author: Cristina Consolandi |
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34 | // |
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35 | // Creation date: 05.10.2010 from G4eCoulombScatteringModel |
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36 | // & G4CoulombScatteringModel |
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37 | // |
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38 | // Class Description: |
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39 | // Single Scattering Model for |
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40 | // for protons, alpha and heavy Ions |
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41 | // |
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42 | // Reference: |
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43 | // M.J. Boschini et al. "Nuclear and Non-Ionizing Energy-Loss |
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44 | // for Coulomb ScatteredParticles from Low Energy up to Relativistic |
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45 | // Regime in Space Radiation Environment" |
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46 | // Accepted for publication in the Proceedings of the ICATPP Conference |
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47 | // on Cosmic Rays for Particle and Astroparticle Physics, Villa Olmo, 7-8 |
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48 | // October, 2010, to be published by World Scientific (Singapore). |
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49 | // |
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50 | // Available for downloading at: |
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51 | // http://arxiv.org/abs/1011.4822 |
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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 | |
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57 | |
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58 | #include "G4IonCoulombScatteringModel.hh" |
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59 | #include "Randomize.hh" |
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60 | //#include "G4DataVector.hh" |
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61 | #include "G4ParticleChangeForGamma.hh" |
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62 | #include "G4Proton.hh" |
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63 | #include "G4ProductionCutsTable.hh" |
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64 | #include "G4NucleiProperties.hh" |
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65 | |
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66 | #include "G4UnitsTable.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 | using namespace std; |
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71 | |
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72 | G4IonCoulombScatteringModel::G4IonCoulombScatteringModel(const G4String& nam) |
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73 | : G4VEmModel(nam), |
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74 | |
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75 | cosThetaMin(1.0), |
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76 | isInitialised(false) |
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77 | { |
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78 | fNistManager = G4NistManager::Instance(); |
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79 | theParticleTable = G4ParticleTable::GetParticleTable(); |
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80 | theProton = G4Proton::Proton(); |
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81 | |
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82 | pCuts=0; |
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83 | currentMaterial = 0; |
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84 | currentElement = 0; |
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85 | currentCouple = 0; |
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86 | |
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87 | lowEnergyLimit = 100*eV; |
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88 | recoilThreshold = 0.*eV; |
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89 | heavycorr =0; |
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90 | particle = 0; |
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91 | mass=0; |
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92 | |
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93 | ioncross = new G4IonCoulombCrossSection(); |
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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 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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99 | |
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100 | G4IonCoulombScatteringModel::~G4IonCoulombScatteringModel() |
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101 | { delete ioncross;} |
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102 | |
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103 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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104 | |
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105 | void G4IonCoulombScatteringModel::Initialise(const G4ParticleDefinition* p, |
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106 | const G4DataVector& ) |
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107 | { |
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108 | SetupParticle(p); |
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109 | currentCouple = 0; |
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110 | cosThetaMin = cos(PolarAngleLimit()); |
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111 | ioncross->Initialise(p,cosThetaMin); |
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112 | |
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113 | pCuts = G4ProductionCutsTable::GetProductionCutsTable()->GetEnergyCutsVector(3); |
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114 | |
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115 | |
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116 | if(!isInitialised) { |
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117 | isInitialised = true; |
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118 | fParticleChange = GetParticleChangeForGamma(); |
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119 | } |
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120 | } |
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121 | |
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122 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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123 | |
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124 | G4double G4IonCoulombScatteringModel::ComputeCrossSectionPerAtom( |
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125 | const G4ParticleDefinition* p, |
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126 | G4double kinEnergy, |
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127 | G4double Z, |
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128 | G4double, |
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129 | G4double cutEnergy, |
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130 | G4double) |
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131 | { |
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132 | |
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133 | SetupParticle(p); |
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134 | |
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135 | G4double xsec =0.0; |
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136 | if(kinEnergy < lowEnergyLimit) return xsec; |
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137 | |
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138 | DefineMaterial(CurrentCouple()); |
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139 | |
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140 | G4int iz = G4int(Z); |
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141 | |
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142 | //from lab to pCM & mu_rel of effective particle |
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143 | ioncross->SetupKinematic(kinEnergy, cutEnergy,iz); |
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144 | |
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145 | |
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146 | ioncross->SetupTarget(Z, kinEnergy, heavycorr); |
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147 | |
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148 | |
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149 | xsec = ioncross->NuclearCrossSection(); |
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150 | |
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151 | //cout<< "..........xsec "<<G4BestUnit(xsec,"Surface") <<endl; |
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152 | return xsec; |
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153 | } |
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154 | |
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155 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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156 | |
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157 | void G4IonCoulombScatteringModel::SampleSecondaries( |
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158 | std::vector<G4DynamicParticle*>* fvect, |
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159 | const G4MaterialCutsCouple* couple, |
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160 | const G4DynamicParticle* dp, |
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161 | G4double cutEnergy, |
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162 | G4double) |
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163 | { |
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164 | G4double kinEnergy = dp->GetKineticEnergy(); |
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165 | |
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166 | if(kinEnergy < lowEnergyLimit) return; |
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167 | |
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168 | DefineMaterial(couple); |
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169 | |
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170 | SetupParticle(dp->GetDefinition()); |
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171 | |
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172 | // Choose nucleus |
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173 | currentElement = SelectRandomAtom(couple,particle, |
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174 | kinEnergy,cutEnergy,kinEnergy); |
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175 | |
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176 | G4double Z = currentElement->GetZ(); |
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177 | G4int iz = G4int(Z); |
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178 | G4int ia = SelectIsotopeNumber(currentElement); |
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179 | G4double m2 = G4NucleiProperties::GetNuclearMass(ia, iz); |
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180 | |
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181 | |
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182 | |
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183 | G4double xsec= ComputeCrossSectionPerAtom(particle,kinEnergy, Z, |
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184 | kinEnergy, cutEnergy, kinEnergy) ; |
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185 | if(xsec == 0.0)return; |
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186 | |
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187 | //scattering angle, z1 == (1-cost) |
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188 | G4double z1 = ioncross->SampleCosineTheta(); |
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189 | |
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190 | if(z1 <= 0.0) { return; } |
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191 | |
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192 | G4double cost = 1.0 - z1; |
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193 | G4double sint = sqrt(z1*(1.0 + cost)); |
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194 | G4double phi = twopi * G4UniformRand(); |
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195 | |
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196 | |
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197 | // kinematics in the Lab system |
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198 | G4double etot = kinEnergy + mass; |
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199 | G4double mom2= kinEnergy*(kinEnergy+2.0*mass); |
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200 | G4double ptot = sqrt(mom2); |
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201 | |
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202 | //CM particle 1 |
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203 | G4double bet = ptot/(etot + m2); |
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204 | G4double gam = 1.0/sqrt((1.0 - bet)*(1.0 + bet)); |
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205 | |
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206 | //CM |
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207 | G4double momCM2= ioncross->GetMomentum2(); |
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208 | G4double momCM =std::sqrt(momCM2); |
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209 | //energy & momentum after scattering of incident particle |
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210 | G4double pxCM = momCM*sint*cos(phi); |
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211 | G4double pyCM = momCM*sint*sin(phi); |
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212 | G4double pzCM = momCM*cost; |
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213 | G4double eCM = sqrt(momCM2 + mass*mass); |
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214 | |
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215 | //CM--->Lab |
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216 | G4ThreeVector v1(pxCM , pyCM, gam*(pzCM + bet*eCM)); |
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217 | G4ThreeVector dir = dp->GetMomentumDirection(); |
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218 | |
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219 | G4ThreeVector newDirection = v1.unit(); |
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220 | newDirection.rotateUz(dir); |
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221 | |
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222 | fParticleChange->ProposeMomentumDirection(newDirection); |
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223 | |
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224 | // recoil....................................... |
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225 | G4double trec =(1.0 - cost)* m2*(etot*etot - mass*mass )/ |
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226 | (mass*mass + m2*m2+ 2.*m2*etot); |
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227 | |
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228 | G4double finalT = kinEnergy - trec; |
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229 | |
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230 | |
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231 | if(finalT <= lowEnergyLimit) { |
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232 | trec = kinEnergy; |
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233 | finalT = 0.0; |
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234 | } |
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235 | |
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236 | fParticleChange->SetProposedKineticEnergy(finalT); |
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237 | |
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238 | G4double tcut = recoilThreshold; |
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239 | if(pCuts) { tcut= std::max(tcut,(*pCuts)[currentMaterialIndex]); |
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240 | |
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241 | //G4cout<<" tcut eV "<<tcut/eV<<endl; |
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242 | } |
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243 | |
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244 | if(trec > tcut) { |
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245 | G4ParticleDefinition* ion = theParticleTable->FindIon(iz, ia, 0, iz); |
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246 | G4double plab = sqrt(finalT*(finalT + 2.0*mass)); |
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247 | G4ThreeVector p2 = (ptot*dir - plab*newDirection).unit(); |
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248 | G4DynamicParticle* newdp = new G4DynamicParticle(ion, p2, trec); |
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249 | fvect->push_back(newdp); |
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250 | } else if(trec > 0.0) { |
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251 | fParticleChange->ProposeLocalEnergyDeposit(trec); |
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252 | fParticleChange->ProposeNonIonizingEnergyDeposit(trec); |
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253 | } |
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254 | |
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255 | |
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256 | } |
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257 | |
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258 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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259 | |
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