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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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9 | // * include a list of copyright holders. * |
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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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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 | // |
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27 | // ------------------------------------------------------------------- |
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28 | // |
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29 | // GEANT4 Class file |
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30 | // |
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31 | // |
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32 | // File name: G4hBetheBlochModel |
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33 | // |
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34 | // Author: V.Ivanchenko (Vladimir.Ivanchenko@cern.ch) |
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35 | // |
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36 | // Creation date: 20 July 2000 |
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37 | // |
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38 | // Modifications: |
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39 | // 20/07/2000 V.Ivanchenko First implementation |
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40 | // 03/10/2000 V.Ivanchenko clean up accoding to CodeWizard |
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41 | // |
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42 | // Class Description: |
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43 | // |
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44 | // Bethe-Bloch ionisation model |
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45 | // |
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46 | // Class Description: End |
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47 | // |
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48 | // ------------------------------------------------------------------- |
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49 | // |
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50 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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51 | |
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52 | #include "G4hBetheBlochModel.hh" |
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53 | #include "G4DynamicParticle.hh" |
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54 | #include "G4ParticleDefinition.hh" |
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55 | #include "G4Material.hh" |
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56 | #include "globals.hh" |
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57 | |
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58 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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59 | |
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60 | G4hBetheBlochModel::G4hBetheBlochModel(const G4String& name) |
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61 | : G4VLowEnergyModel(name), |
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62 | lowEnergyLimit(1.*MeV), |
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63 | highEnergyLimit(100.*GeV), |
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64 | twoln10(2.*std::log(10.)), |
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65 | bg2lim(0.0169), |
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66 | taulim(8.4146e-3) |
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67 | {;} |
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68 | |
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69 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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70 | |
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71 | G4hBetheBlochModel::~G4hBetheBlochModel() |
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72 | {;} |
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73 | |
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74 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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75 | |
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76 | G4double G4hBetheBlochModel::TheValue(const G4DynamicParticle* particle, |
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77 | const G4Material* material) |
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78 | { |
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79 | G4double energy = particle->GetKineticEnergy() ; |
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80 | G4double particleMass = particle->GetMass() ; |
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81 | |
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82 | G4double eloss = BetheBlochFormula(material,energy,particleMass) ; |
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83 | |
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84 | return eloss ; |
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85 | } |
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86 | |
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87 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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88 | |
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89 | G4double G4hBetheBlochModel::TheValue(const G4ParticleDefinition* aParticle, |
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90 | const G4Material* material, |
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91 | G4double kineticEnergy) |
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92 | { |
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93 | G4double particleMass = aParticle->GetPDGMass() ; |
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94 | G4double eloss = BetheBlochFormula(material,kineticEnergy,particleMass) ; |
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95 | |
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96 | return eloss ; |
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97 | } |
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98 | |
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99 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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100 | |
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101 | G4double G4hBetheBlochModel::HighEnergyLimit( |
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102 | const G4ParticleDefinition* , |
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103 | const G4Material* ) const |
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104 | { |
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105 | return highEnergyLimit ; |
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106 | } |
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107 | |
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108 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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109 | |
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110 | G4double G4hBetheBlochModel::LowEnergyLimit( |
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111 | const G4ParticleDefinition* aParticle, |
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112 | const G4Material* material) const |
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113 | { |
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114 | G4double taul = (material->GetIonisation()->GetTaul())* |
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115 | (aParticle->GetPDGMass()) ; |
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116 | return taul ; |
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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 | G4double G4hBetheBlochModel::HighEnergyLimit( |
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122 | const G4ParticleDefinition* ) const |
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123 | { |
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124 | return highEnergyLimit ; |
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125 | } |
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126 | |
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127 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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128 | |
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129 | G4double G4hBetheBlochModel::LowEnergyLimit( |
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130 | const G4ParticleDefinition* ) const |
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131 | { |
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132 | return lowEnergyLimit ; |
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133 | } |
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134 | |
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135 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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136 | |
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137 | G4bool G4hBetheBlochModel::IsInCharge(const G4DynamicParticle* , |
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138 | const G4Material* ) const |
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139 | { |
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140 | return true ; |
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141 | } |
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142 | |
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143 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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144 | |
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145 | G4bool G4hBetheBlochModel::IsInCharge(const G4ParticleDefinition* , |
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146 | const G4Material* ) const |
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147 | { |
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148 | return true ; |
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149 | } |
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150 | |
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151 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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152 | |
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153 | G4double G4hBetheBlochModel::BetheBlochFormula( |
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154 | const G4Material* material, |
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155 | G4double kineticEnergy, |
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156 | G4double particleMass) const |
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157 | { |
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158 | // This member function is applied normally to proton/antiproton |
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159 | G4double ionloss ; |
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160 | |
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161 | G4double rateMass = electron_mass_c2/particleMass ; |
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162 | |
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163 | G4double taul = material->GetIonisation()->GetTaul() ; |
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164 | G4double tau = kineticEnergy/particleMass ; // tau is relative energy |
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165 | |
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166 | // It is not normal case for this function |
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167 | // for low energy parametrisation have to be applied |
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168 | if ( tau < taul ) tau = taul ; |
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169 | |
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170 | // some local variables |
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171 | |
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172 | G4double gamma,bg2,beta2,tmax,x,delta,sh ; |
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173 | G4double electronDensity = material->GetElectronDensity(); |
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174 | G4double eexc = material->GetIonisation()->GetMeanExcitationEnergy(); |
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175 | G4double eexc2 = eexc*eexc ; |
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176 | G4double cden = material->GetIonisation()->GetCdensity(); |
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177 | G4double mden = material->GetIonisation()->GetMdensity(); |
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178 | G4double aden = material->GetIonisation()->GetAdensity(); |
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179 | G4double x0den = material->GetIonisation()->GetX0density(); |
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180 | G4double x1den = material->GetIonisation()->GetX1density(); |
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181 | G4double* shellCorrectionVector = |
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182 | material->GetIonisation()->GetShellCorrectionVector(); |
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183 | |
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184 | gamma = tau + 1.0 ; |
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185 | bg2 = tau*(tau+2.0) ; |
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186 | beta2 = bg2/(gamma*gamma) ; |
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187 | tmax = 2.*electron_mass_c2*bg2/(1.+2.*gamma*rateMass+rateMass*rateMass) ; |
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188 | |
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189 | ionloss = std::log(2.0*electron_mass_c2*bg2*tmax/eexc2)-2.0*beta2 ; |
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190 | |
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191 | // density correction |
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192 | x = std::log(bg2)/twoln10 ; |
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193 | if ( x < x0den ) { |
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194 | delta = 0.0 ; |
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195 | |
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196 | } else { |
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197 | delta = twoln10*x - cden ; |
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198 | if ( x < x1den ) delta += aden*std::pow((x1den-x),mden) ; |
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199 | } |
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200 | |
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201 | // shell correction |
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202 | sh = 0.0 ; |
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203 | x = 1.0 ; |
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204 | |
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205 | if ( bg2 > bg2lim ) { |
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206 | for (G4int k=0; k<=2; k++) { |
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207 | x *= bg2 ; |
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208 | sh += shellCorrectionVector[k]/x; |
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209 | } |
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210 | |
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211 | } else { |
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212 | for (G4int k=0; k<=2; k++) { |
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213 | x *= bg2lim ; |
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214 | sh += shellCorrectionVector[k]/x; |
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215 | } |
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216 | sh *= std::log(tau/taul)/std::log(taulim/taul) ; |
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217 | } |
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218 | |
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219 | // now compute the total ionization loss |
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220 | |
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221 | ionloss -= delta + sh ; |
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222 | ionloss *= twopi_mc2_rcl2*electronDensity/beta2 ; |
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223 | |
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224 | if ( ionloss < 0.0) ionloss = 0.0 ; |
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225 | |
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226 | return ionloss; |
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227 | } |
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228 | |
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229 | |
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