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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7 | // * conditions of the Geant4 Software License, included in the file * |
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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 | // |
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27 | // $Id: G4LCapture.cc,v 1.14 2007/02/24 05:17:29 dennis Exp $ |
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28 | // GEANT4 tag $Name: geant4-09-03-ref-09 $ |
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29 | // |
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30 | // |
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31 | // G4 Model: Low-energy Neutron Capture |
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32 | // F.W. Jones, TRIUMF, 03-DEC-96 |
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33 | // |
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34 | // This is a prototype of a low-energy neutron capture process. |
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35 | // Currently it is based on the GHEISHA routine CAPTUR, |
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36 | // and conforms fairly closely to the original Fortran. |
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37 | // |
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38 | // HPW Capture using models now. the code comes from the |
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39 | // original G4LCapture class. |
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40 | // |
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41 | // 25-JUN-98 FWJ: replaced missing Initialize for ParticleChange. |
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42 | // |
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43 | |
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44 | #include "globals.hh" |
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45 | #include "G4LCapture.hh" |
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46 | #include "Randomize.hh" |
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47 | |
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48 | G4LCapture::G4LCapture() : |
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49 | G4HadronicInteraction("G4LCapture") |
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50 | { |
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51 | SetMinEnergy( 0.0*GeV ); |
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52 | SetMaxEnergy( DBL_MAX ); |
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53 | } |
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54 | |
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55 | G4LCapture::~G4LCapture() |
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56 | { |
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57 | theParticleChange.Clear(); |
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58 | } |
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59 | |
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60 | G4HadFinalState* |
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61 | G4LCapture::ApplyYourself(const G4HadProjectile & aTrack, G4Nucleus& targetNucleus) |
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62 | { |
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63 | |
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64 | theParticleChange.Clear(); |
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65 | theParticleChange.SetStatusChange(stopAndKill); |
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66 | |
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67 | G4double N = targetNucleus.GetN(); |
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68 | G4double Z = targetNucleus.GetZ(); |
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69 | |
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70 | const G4LorentzVector theMom = aTrack.Get4Momentum(); |
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71 | G4double P = theMom.vect().mag()/GeV; |
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72 | G4double Px = theMom.vect().x()/GeV; |
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73 | G4double Py = theMom.vect().y()/GeV; |
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74 | G4double Pz = theMom.vect().z()/GeV; |
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75 | G4double E = theMom.e()/GeV; |
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76 | G4double E0 = aTrack.GetDefinition()->GetPDGMass()/GeV; |
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77 | G4double Q = aTrack.GetDefinition()->GetPDGCharge(); |
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78 | if (verboseLevel > 1) { |
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79 | G4cout << "G4LCapture:ApplyYourself: incident particle:" << G4endl; |
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80 | G4cout << "P " << P << " GeV/c" << G4endl; |
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81 | G4cout << "Px " << Px << " GeV/c" << G4endl; |
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82 | G4cout << "Py " << Py << " GeV/c" << G4endl; |
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83 | G4cout << "Pz " << Pz << " GeV/c" << G4endl; |
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84 | G4cout << "E " << E << " GeV" << G4endl; |
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85 | G4cout << "mass " << E0 << " GeV" << G4endl; |
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86 | G4cout << "charge " << Q << G4endl; |
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87 | } |
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88 | |
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89 | // GHEISHA ADD operation to get total energy, mass, charge: |
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90 | |
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91 | if (verboseLevel > 1) { |
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92 | G4cout << "G4LCapture:ApplyYourself: material:" << G4endl; |
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93 | G4cout << "A " << N << G4endl; |
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94 | G4cout << "Z " << Z << G4endl; |
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95 | G4cout << "atomic mass " << |
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96 | Atomas(N, Z) << "GeV" << G4endl; |
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97 | } |
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98 | E = E + Atomas(N, Z); |
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99 | G4double E02 = E*E - P*P; |
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100 | E0 = std::sqrt(std::abs(E02)); |
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101 | if (E02 < 0) E0 = -E0; |
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102 | Q = Q + Z; |
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103 | if (verboseLevel > 1) { |
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104 | G4cout << "G4LCapture:ApplyYourself: total:" << G4endl; |
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105 | G4cout << "E " << E << " GeV" << G4endl; |
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106 | G4cout << "mass " << E0 << " GeV" << G4endl; |
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107 | G4cout << "charge " << Q << G4endl; |
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108 | } |
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109 | Px = -Px; |
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110 | Py = -Py; |
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111 | Pz = -Pz; |
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112 | |
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113 | // Make a gamma... |
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114 | |
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115 | G4double p; |
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116 | if (Z == 1 && N == 1) { // special case for hydrogen |
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117 | p = 0.0022; |
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118 | } else { |
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119 | G4double ran = G4RandGauss::shoot(); |
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120 | p = 0.0065 + ran*0.0010; |
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121 | } |
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122 | |
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123 | G4double ran1 = G4UniformRand(); |
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124 | G4double ran2 = G4UniformRand(); |
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125 | G4double cost = -1. + 2.*ran1; |
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126 | G4double sint = std::sqrt(std::abs(1. - cost*cost)); |
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127 | G4double phi = ran2*twopi; |
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128 | |
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129 | G4double px = p*sint*std::sin(phi); |
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130 | G4double py = p*sint*std::cos(phi); |
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131 | G4double pz = p*cost; |
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132 | G4double e = p; |
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133 | G4double e0 = 0.; |
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134 | |
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135 | G4double a = px*Px + py*Py + pz*Pz; |
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136 | a = (a/(E + E0) - e)/E0; |
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137 | |
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138 | px = px + a*Px; |
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139 | py = py + a*Py; |
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140 | pz = pz + a*Pz; |
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141 | |
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142 | G4DynamicParticle* aGamma; |
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143 | aGamma = new G4DynamicParticle(G4Gamma::GammaDefinition(), |
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144 | G4ThreeVector(px*GeV, py*GeV, pz*GeV)); |
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145 | theParticleChange.AddSecondary(aGamma); |
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146 | |
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147 | // Make another gamma if there is sufficient energy left over... |
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148 | |
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149 | G4double xp = 0.008 - p; |
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150 | if (xp > 0.) { |
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151 | if (Z > 1 || N > 1) { |
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152 | ran1 = G4UniformRand(); |
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153 | ran2 = G4UniformRand(); |
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154 | cost = -1. + 2.*ran1; |
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155 | sint = std::sqrt(std::abs(1. - cost*cost)); |
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156 | phi = ran2*twopi; |
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157 | |
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158 | px = xp*sint*std::sin(phi); |
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159 | py = xp*sint*std::cos(phi); |
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160 | pz = xp*cost; |
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161 | e = xp; |
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162 | e0 = 0.; |
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163 | |
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164 | a = px*Px + py*Py + pz*Pz; |
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165 | a = (a/(E + E0) - e)/E0; |
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166 | |
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167 | px = px + a*Px; |
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168 | py = py + a*Py; |
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169 | pz = pz + a*Pz; |
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170 | |
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171 | aGamma = new G4DynamicParticle(G4Gamma::GammaDefinition(), |
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172 | G4ThreeVector(px*GeV, py*GeV, pz*GeV)); |
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173 | theParticleChange.AddSecondary(aGamma); |
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174 | } |
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175 | } |
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176 | return &theParticleChange; |
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177 | } |
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