1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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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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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 | // * * |
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21 | // * Parts of this code which have been developed by QinetiQ Ltd * |
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22 | // * under contract to the European Space Agency (ESA) are the * |
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23 | // * intellectual property of ESA. Rights to use, copy, modify and * |
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24 | // * redistribute this software for general public use are granted * |
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25 | // * in compliance with any licensing, distribution and development * |
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26 | // * policy adopted by the Geant4 Collaboration. This code has been * |
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27 | // * written by QinetiQ Ltd for the European Space Agency, under ESA * |
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28 | // * contract 17191/03/NL/LvH (Aurora Programme). * |
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29 | // * * |
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30 | // * By using, copying, modifying or distributing the software (or * |
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31 | // * any work based on the software) you agree to acknowledge its * |
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32 | // * use in resulting scientific publications, and indicate your * |
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33 | // * acceptance of all terms of the Geant4 Software license. * |
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34 | // ******************************************************************** |
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35 | // |
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36 | // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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37 | // |
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38 | // MODULE: G4TripathiLightCrossSection.cc |
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39 | // |
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40 | // Version: B.1 |
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41 | // Date: 15/04/04 |
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42 | // Author: P R Truscott |
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43 | // Organisation: QinetiQ Ltd, UK |
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44 | // Customer: ESA/ESTEC, NOORDWIJK |
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45 | // Contract: 17191/03/NL/LvH |
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46 | // |
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47 | // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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48 | // |
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49 | // CHANGE HISTORY |
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50 | // -------------- |
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51 | // |
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52 | // 6 October 2003, P R Truscott, QinetiQ Ltd, UK |
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53 | // Created. |
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54 | // |
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55 | // 15 March 2004, P R Truscott, QinetiQ Ltd, UK |
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56 | // Beta release |
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57 | // |
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58 | // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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59 | /////////////////////////////////////////////////////////////////////////////// |
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60 | // |
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61 | #include "G4TripathiLightCrossSection.hh" |
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62 | #include "G4WilsonRadius.hh" |
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63 | #include "G4ParticleTable.hh" |
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64 | #include "G4IonTable.hh" |
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65 | |
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66 | /////////////////////////////////////////////////////////////////////////////// |
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67 | // |
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68 | G4TripathiLightCrossSection::G4TripathiLightCrossSection () |
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69 | { |
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70 | // |
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71 | // |
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72 | // Constructor only needs to instantiate the object which provides functions |
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73 | // to calculate the nuclear radius, and some other constants used to |
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74 | // calculate cross-sections. |
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75 | // |
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76 | theWilsonRadius = new G4WilsonRadius(); |
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77 | r_0 = 1.1 * fermi; |
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78 | third = 1.0/3.0; |
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79 | // |
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80 | // |
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81 | // The following variable is set to true if |
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82 | // G4TripathiLightCrossSection::GetCrossSection is going to be called from |
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83 | // within G4TripathiLightCrossSection::GetCrossSection to check whether the |
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84 | // cross-section is behaviing anomalously in the low-energy region. |
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85 | // |
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86 | lowEnergyCheck = false; |
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87 | } |
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88 | /////////////////////////////////////////////////////////////////////////////// |
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89 | // |
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90 | G4TripathiLightCrossSection::~G4TripathiLightCrossSection () |
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91 | { |
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92 | // |
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93 | // |
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94 | // Destructor just needs to delete the pointer to the G4WilsonRadius object. |
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95 | // |
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96 | delete theWilsonRadius; |
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97 | } |
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98 | /////////////////////////////////////////////////////////////////////////////// |
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99 | // |
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100 | G4bool G4TripathiLightCrossSection::IsApplicable |
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101 | (const G4DynamicParticle* theProjectile, const G4Element* theTarget) |
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102 | { |
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103 | return IsZAApplicable(theProjectile, theTarget->GetZ(), theTarget->GetN()); |
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104 | } |
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105 | |
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106 | |
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107 | G4bool G4TripathiLightCrossSection::IsZAApplicable |
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108 | (const G4DynamicParticle* theProjectile, G4double ZZ, G4double AA) |
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109 | { |
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110 | G4bool result = false; |
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111 | const G4double AT = AA; |
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112 | const G4double ZT = ZZ; |
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113 | const G4double ZP = theProjectile->GetDefinition()->GetPDGCharge(); |
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114 | const G4double AP = theProjectile->GetDefinition()->GetBaryonNumber(); |
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115 | if (theProjectile->GetKineticEnergy()/ |
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116 | theProjectile->GetDefinition()->GetBaryonNumber()<10.0*GeV && |
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117 | ((AT==1 && ZT==1) || (AP==1 && ZP==1) || |
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118 | (AT==1 && ZT==0) || (AP==1 && ZP==0) || |
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119 | (AT==2 && ZT==1) || (AP==2 && ZP==1) || |
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120 | (AT==3 && ZT==2) || (AP==3 && ZP==2) || |
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121 | (AT==4 && ZT==2) || (AP==4 && ZP==2))) result = true; |
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122 | return result; |
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123 | } |
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124 | /////////////////////////////////////////////////////////////////////////////// |
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125 | // |
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126 | G4double G4TripathiLightCrossSection::GetIsoZACrossSection |
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127 | (const G4DynamicParticle* theProjectile, G4double ZZ, G4double AA, |
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128 | G4double /*theTemperature*/) |
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129 | { |
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130 | // |
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131 | // Initialise the result. |
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132 | G4double result = 0.0; |
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133 | // |
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134 | // |
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135 | // Get details of the projectile and target (nucleon number, atomic number, |
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136 | // kinetic enery and energy/nucleon. |
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137 | // |
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138 | const G4double AT = AA; |
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139 | const G4double ZT = ZZ; |
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140 | const G4double EA = theProjectile->GetKineticEnergy()/MeV; |
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141 | const G4double AP = theProjectile->GetDefinition()->GetBaryonNumber(); |
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142 | const G4double ZP = theProjectile->GetDefinition()->GetPDGCharge(); |
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143 | G4double E = EA / AP; |
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144 | // |
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145 | // |
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146 | // Determine target mass and energy within the centre-of-mass frame. |
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147 | // |
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148 | G4double mT = G4ParticleTable::GetParticleTable() |
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149 | ->GetIonTable() |
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150 | ->GetIonMass(static_cast<G4int>(ZT), static_cast<G4int>(AT)); |
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151 | G4LorentzVector pT(0.0, 0.0, 0.0, mT); |
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152 | G4LorentzVector pP(theProjectile->Get4Momentum()); |
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153 | pT = pT + pP; |
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154 | G4double E_cm = (pT.mag()-mT-pP.m())/MeV; |
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155 | if(E_cm <= DBL_MIN) return result; |
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156 | |
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157 | |
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158 | // |
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159 | // |
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160 | // Determine nuclear radii. Note that the r_p and r_T are defined differently |
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161 | // from Wilson et al. |
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162 | // |
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163 | G4WilsonRadius theWilsonNuclearRadius; |
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164 | G4double r_rms_p = theWilsonRadius->GetWilsonRMSRadius(AP); |
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165 | G4double r_rms_t = theWilsonRadius->GetWilsonRMSRadius(AT); |
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166 | |
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167 | G4double r_p = 1.29*r_rms_p; |
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168 | G4double r_t = 1.29*r_rms_t; |
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169 | |
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170 | G4double Radius = (r_p + r_t)/fermi + 1.2*(std::pow(AT, third) + std::pow(AP, third))/ |
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171 | std::pow(E_cm, third); |
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172 | |
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173 | G4double B = 1.44 * ZP * ZT / Radius; |
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174 | if(E_cm <= B) return result; |
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175 | |
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176 | // |
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177 | // Now determine other parameters associated with the parametric |
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178 | // formula, depending upon the projectile and target. |
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179 | // |
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180 | G4double T1 = 0.0; |
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181 | G4double D = 0.0; |
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182 | G4double G = 0.0; |
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183 | |
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184 | if ((AT==1 && ZT==1) || (AP==1 && ZP==1)) |
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185 | { |
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186 | T1 = 23.0; |
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187 | D = 1.85 + 0.16/(1+std::exp((500.0-E)/200.0)); |
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188 | } |
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189 | else if ((AT==1 && ZT==0) || (AP==1 && ZP==0)) |
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190 | { |
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191 | T1 = 18.0; |
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192 | D = 1.85 + 0.16/(1+std::exp((500.0-E)/200.0)); |
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193 | } |
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194 | else if ((AT==2 && ZT==1) || (AP==2 && ZP==1)) |
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195 | { |
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196 | T1 = 23.0; |
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197 | D = 1.65 + 0.1/(1+std::exp((500.0-E)/200.0)); |
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198 | } |
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199 | else if ((AT==3 && ZT==2) || (AP==3 && ZP==2)) |
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200 | { |
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201 | T1 = 40.0; |
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202 | D = 1.55; |
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203 | } |
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204 | else if (AP==4 && ZP==2) |
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205 | { |
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206 | if (AT==4 && ZT==2) {T1 = 40.0; G = 300.0;} |
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207 | else if (ZT==4) {T1 = 25.0; G = 300.0;} |
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208 | else if (ZT==7) {T1 = 40.0; G = 500.0;} |
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209 | else if (ZT==13) {T1 = 25.0; G = 300.0;} |
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210 | else if (ZT==26) {T1 = 40.0; G = 300.0;} |
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211 | else {T1 = 40.0; G = 75.0;} |
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212 | D = 2.77 - 8.0E-3*AT + 1.8E-5*AT*AT-0.8/(1.0+std::exp((250.0-E)/G)); |
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213 | } |
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214 | else if (AT==4 && ZT==2) |
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215 | { |
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216 | if (AP==4 && ZP==2) {T1 = 40.0; G = 300.0;} |
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217 | else if (ZP==4) {T1 = 25.0; G = 300.0;} |
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218 | else if (ZP==7) {T1 = 40.0; G = 500.0;} |
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219 | else if (ZP==13) {T1 = 25.0; G = 300.0;} |
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220 | else if (ZP==26) {T1 = 40.0; G = 300.0;} |
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221 | else {T1 = 40.0; G = 75.0;} |
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222 | D = 2.77 - 8.0E-3*AP + 1.8E-5*AP*AP-0.8/(1.0+std::exp((250.0-E)/G)); |
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223 | } |
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224 | // |
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225 | // |
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226 | // C_E, S, deltaE, X1, S_L and X_m correspond directly with the original |
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227 | // formulae of Tripathi et al in his report. |
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228 | // |
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229 | G4double C_E = D*(1.0-std::exp(-E/T1)) - |
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230 | 0.292*std::exp(-E/792.0)*std::cos(0.229*std::pow(E,0.453)); |
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231 | |
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232 | G4double S = std::pow(AP,third)*std::pow(AT,third)/(std::pow(AP,third) + std::pow(AT,third)); |
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233 | |
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234 | G4double deltaE = 0.0; |
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235 | G4double X1 = 0.0; |
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236 | if (AT >= AP) |
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237 | { |
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238 | deltaE = 1.85*S + 0.16*S/std::pow(E_cm,third) - C_E + 0.91*(AT-2.0*ZT)*ZP/AT/AP; |
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239 | X1 = 2.83 - 3.1E-2*AT + 1.7E-4*AT*AT; |
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240 | } |
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241 | else |
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242 | { |
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243 | deltaE = 1.85*S + 0.16*S/std::pow(E_cm,third) - C_E + 0.91*(AP-2.0*ZP)*ZT/AT/AP; |
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244 | X1 = 2.83 - 3.1E-2*AP + 1.7E-4*AP*AP; |
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245 | } |
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246 | G4double S_L = 1.2 + 1.6*(1.0-std::exp(-E/15.0)); |
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247 | G4double X_m = 1.0 - X1*std::exp(-E/X1*S_L); |
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248 | // |
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249 | // |
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250 | // R_c is also highly dependent upon the A and Z of the projectile and |
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251 | // target. |
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252 | // |
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253 | G4double R_c = 1.0; |
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254 | if (AP==1 && ZP==1) |
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255 | { |
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256 | if (AT==2 && ZT==1) R_c = 13.5; |
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257 | else if (AT==3 && ZT==2) R_c = 21.0; |
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258 | else if (AT==4 && ZT==2) R_c = 27.0; |
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259 | else if (ZT==3) R_c = 2.2; |
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260 | } |
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261 | else if (AT==1 && ZT==1) |
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262 | { |
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263 | if (AP==2 && ZP==1) R_c = 13.5; |
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264 | else if (AP==3 && ZP==2) R_c = 21.0; |
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265 | else if (AP==4 && ZP==2) R_c = 27.0; |
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266 | else if (ZP==3) R_c = 2.2; |
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267 | } |
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268 | else if (AP==2 && ZP==1) |
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269 | { |
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270 | if (AT==2 && ZT==1) R_c = 13.5; |
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271 | else if (AT==4 && ZT==2) R_c = 13.5; |
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272 | else if (AT==12 && ZT==6) R_c = 6.0; |
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273 | } |
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274 | else if (AT==2 && ZT==1) |
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275 | { |
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276 | if (AP==2 && ZP==1) R_c = 13.5; |
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277 | else if (AP==4 && ZP==2) R_c = 13.5; |
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278 | else if (AP==12 && ZP==6) R_c = 6.0; |
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279 | } |
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280 | else if ((AP==4 && ZP==2 && (ZT==73 || ZT==79)) || |
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281 | (AT==4 && ZT==2 && (ZP==73 || ZP==79))) R_c = 0.6; |
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282 | // |
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283 | // |
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284 | // Find the total cross-section. Check that it's value is positive, and if |
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285 | // the energy is less that 10 MeV/nuc, find out if the cross-section is |
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286 | // increasing with decreasing energy. If so this is a sign that the function |
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287 | // is behaving badly at low energies, and the cross-section should be |
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288 | // set to zero. |
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289 | // |
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290 | result = pi * r_0*r_0 * |
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291 | std::pow((std::pow(AT,third) + std::pow(AP,third) + deltaE),2.0) * |
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292 | (1.0 - R_c*B/E_cm) * X_m; |
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293 | if (!lowEnergyCheck) |
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294 | { |
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295 | if (result < 0.0) result = 0.0; |
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296 | else if (E < 6.0*MeV) |
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297 | { |
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298 | G4double f = 0.95; |
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299 | G4DynamicParticle slowerProjectile = *theProjectile; |
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300 | slowerProjectile.SetKineticEnergy(f * EA * MeV); |
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301 | G4TripathiLightCrossSection theTripathiLightCrossSection; |
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302 | theTripathiLightCrossSection.SetLowEnergyCheck(true); |
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303 | G4double resultp = |
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304 | theTripathiLightCrossSection.GetIsoZACrossSection |
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305 | (&slowerProjectile, ZZ, AA, 0.0); |
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306 | if (resultp >result) result = 0.0; |
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307 | } |
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308 | } |
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309 | |
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310 | return result; |
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311 | } |
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312 | |
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313 | |
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314 | G4double G4TripathiLightCrossSection::GetCrossSection |
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315 | (const G4DynamicParticle* theProjectile, const G4Element* theTarget, |
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316 | G4double theTemperature) |
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317 | { |
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318 | G4int nIso = theTarget->GetNumberOfIsotopes(); |
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319 | G4double xsection = 0; |
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320 | |
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321 | if (nIso) { |
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322 | G4double sig; |
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323 | G4IsotopeVector* isoVector = theTarget->GetIsotopeVector(); |
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324 | G4double* abundVector = theTarget->GetRelativeAbundanceVector(); |
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325 | G4double ZZ; |
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326 | G4double AA; |
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327 | |
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328 | for (G4int i = 0; i < nIso; i++) { |
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329 | ZZ = G4double( (*isoVector)[i]->GetZ() ); |
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330 | AA = G4double( (*isoVector)[i]->GetN() ); |
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331 | sig = GetIsoZACrossSection(theProjectile, ZZ, AA, theTemperature); |
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332 | xsection += sig*abundVector[i]; |
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333 | } |
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334 | |
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335 | } else { |
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336 | xsection = |
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337 | GetIsoZACrossSection(theProjectile, theTarget->GetZ(), theTarget->GetN(), |
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338 | theTemperature); |
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339 | } |
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340 | |
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341 | return xsection; |
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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 | // |
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347 | void G4TripathiLightCrossSection::SetLowEnergyCheck (G4bool aLowEnergyCheck) |
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348 | { |
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349 | lowEnergyCheck = aLowEnergyCheck; |
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350 | } |
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351 | /////////////////////////////////////////////////////////////////////////////// |
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352 | // |
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