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 | // G4 Low energy model: n-p scattering |
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28 | // F.W. Jones, L.G. Greeniaus, H.P. Wellisch |
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29 | |
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30 | // 11-OCT-2007 F.W. Jones: removed erroneous code for identity |
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31 | // exchange of particles. |
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32 | |
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33 | #include "G4LEnp.hh" |
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34 | #include "Randomize.hh" |
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35 | #include "G4ios.hh" |
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36 | |
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37 | // Initialization of static data arrays: |
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38 | #include "G4LEnpData.hh" |
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39 | #include "Randomize.hh" |
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40 | |
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41 | |
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42 | G4LEnp::G4LEnp():G4HadronicInteraction("G4LEnp") |
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43 | { |
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44 | // theParticleChange.SetNumberOfSecondaries(1); |
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45 | |
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46 | // SetMinEnergy(10.*MeV); |
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47 | // SetMaxEnergy(1200.*MeV); |
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48 | SetMinEnergy(0.); |
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49 | SetMaxEnergy(1200.*GeV); |
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50 | } |
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51 | |
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52 | G4LEnp::~G4LEnp() |
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53 | { |
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54 | theParticleChange.Clear(); |
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55 | } |
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56 | |
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57 | G4HadFinalState* |
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58 | G4LEnp::ApplyYourself(const G4HadProjectile& aTrack, G4Nucleus& targetNucleus) |
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59 | { |
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60 | theParticleChange.Clear(); |
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61 | const G4HadProjectile* aParticle = &aTrack; |
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62 | |
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63 | G4double P = aParticle->GetTotalMomentum(); |
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64 | G4double Px = aParticle->Get4Momentum().x(); |
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65 | G4double Py = aParticle->Get4Momentum().y(); |
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66 | G4double Pz = aParticle->Get4Momentum().z(); |
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67 | G4double ek = aParticle->GetKineticEnergy(); |
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68 | G4ThreeVector theInitial = aParticle->Get4Momentum().vect(); |
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69 | |
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70 | if (verboseLevel > 1) { |
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71 | G4double E = aParticle->GetTotalEnergy(); |
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72 | G4double E0 = aParticle->GetDefinition()->GetPDGMass(); |
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73 | G4double Q = aParticle->GetDefinition()->GetPDGCharge(); |
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74 | G4double N = targetNucleus.GetN(); |
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75 | G4double Z = targetNucleus.GetZ(); |
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76 | G4cout << "G4LEnp:ApplyYourself: incident particle: " |
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77 | << aParticle->GetDefinition()->GetParticleName() << G4endl; |
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78 | G4cout << "P = " << P/GeV << " GeV/c" |
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79 | << ", Px = " << Px/GeV << " GeV/c" |
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80 | << ", Py = " << Py/GeV << " GeV/c" |
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81 | << ", Pz = " << Pz/GeV << " GeV/c" << G4endl; |
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82 | G4cout << "E = " << E/GeV << " GeV" |
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83 | << ", kinetic energy = " << ek/GeV << " GeV" |
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84 | << ", mass = " << E0/GeV << " GeV" |
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85 | << ", charge = " << Q << G4endl; |
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86 | G4cout << "G4LEnp:ApplyYourself: material:" << G4endl; |
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87 | G4cout << "A = " << N |
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88 | << ", Z = " << Z |
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89 | << ", atomic mass " |
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90 | << G4Proton::Proton()->GetPDGMass()/GeV << "GeV" |
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91 | << G4endl; |
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92 | // |
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93 | // GHEISHA ADD operation to get total energy, mass, charge |
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94 | // |
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95 | E += G4Proton::Proton()->GetPDGMass(); |
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96 | G4double E02 = E*E - P*P; |
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97 | E0 = std::sqrt(std::abs(E02)); |
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98 | if (E02 < 0)E0 *= -1; |
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99 | Q += Z; |
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100 | G4cout << "G4LEnp:ApplyYourself: total:" << G4endl; |
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101 | G4cout << "E = " << E/GeV << " GeV" |
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102 | << ", mass = " << E0/GeV << " GeV" |
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103 | << ", charge = " << Q << G4endl; |
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104 | } |
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105 | |
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106 | // Find energy bin |
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107 | |
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108 | G4int je1 = 0; |
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109 | G4int je2 = NENERGY - 1; |
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110 | ek = ek/GeV; |
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111 | do { |
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112 | G4int midBin = (je1 + je2)/2; |
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113 | if (ek < elab[midBin]) |
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114 | je2 = midBin; |
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115 | else |
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116 | je1 = midBin; |
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117 | } while (je2 - je1 > 1); |
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118 | // G4int j; |
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119 | //std::abs(ek-elab[je1]) < std::abs(ek-elab[je2]) ? j = je1 : j = je2; |
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120 | G4double delab = elab[je2] - elab[je1]; |
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121 | |
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122 | // Sample the angle |
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123 | |
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124 | G4float sample = G4UniformRand(); |
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125 | G4int ke1 = 0; |
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126 | G4int ke2 = NANGLE - 1; |
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127 | G4double dsig = sig[je2][0] - sig[je1][0]; |
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128 | G4double rc = dsig/delab; |
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129 | G4double b = sig[je1][0] - rc*elab[je1]; |
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130 | G4double sigint1 = rc*ek + b; |
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131 | G4double sigint2 = 0.; |
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132 | |
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133 | if (verboseLevel > 1) G4cout << "sample=" << sample << G4endl |
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134 | << ke1 << " " << ke2 << " " |
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135 | << sigint1 << " " << sigint2 << G4endl; |
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136 | |
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137 | do { |
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138 | G4int midBin = (ke1 + ke2)/2; |
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139 | dsig = sig[je2][midBin] - sig[je1][midBin]; |
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140 | rc = dsig/delab; |
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141 | b = sig[je1][midBin] - rc*elab[je1]; |
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142 | G4double sigint = rc*ek + b; |
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143 | if (sample < sigint) { |
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144 | ke2 = midBin; |
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145 | sigint2 = sigint; |
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146 | } |
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147 | else { |
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148 | ke1 = midBin; |
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149 | sigint1 = sigint; |
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150 | } |
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151 | if (verboseLevel > 1)G4cout << ke1 << " " << ke2 << " " |
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152 | << sigint1 << " " << sigint2 << G4endl; |
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153 | } while (ke2 - ke1 > 1); |
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154 | |
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155 | // sigint1 and sigint2 should be recoverable from above loop |
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156 | |
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157 | // G4double dsig = sig[je2][ke1] - sig[je1][ke1]; |
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158 | // G4double rc = dsig/delab; |
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159 | // G4double b = sig[je1][ke1] - rc*elab[je1]; |
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160 | // G4double sigint1 = rc*ek + b; |
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161 | |
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162 | // G4double dsig = sig[je2][ke2] - sig[je1][ke2]; |
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163 | // G4double rc = dsig/delab; |
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164 | // G4double b = sig[je1][ke2] - rc*elab[je1]; |
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165 | // G4double sigint2 = rc*ek + b; |
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166 | |
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167 | dsig = sigint2 - sigint1; |
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168 | rc = 1./dsig; |
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169 | b = ke1 - rc*sigint1; |
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170 | G4double kint = rc*sample + b; |
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171 | G4double theta = (0.5 + kint)*pi/180.; |
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172 | |
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173 | // G4int k; |
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174 | //std::abs(sample-sig[j][ke1]) < std::abs(sample-sig[j][ke2]) ? k = ke1 : k = ke2; |
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175 | // G4double theta = (0.5 + k)*pi/180.; |
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176 | |
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177 | if (verboseLevel > 1) { |
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178 | G4cout << " energy bin " << je1 << " energy=" << elab[je1] << G4endl; |
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179 | G4cout << " angle bin " << kint << " angle=" << theta/degree << G4endl; |
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180 | } |
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181 | |
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182 | |
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183 | // Get the target particle |
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184 | |
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185 | G4DynamicParticle* targetParticle = targetNucleus.ReturnTargetParticle(); |
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186 | |
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187 | G4double E1 = aParticle->GetTotalEnergy(); |
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188 | G4double M1 = aParticle->GetDefinition()->GetPDGMass(); |
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189 | G4double E2 = targetParticle->GetTotalEnergy(); |
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190 | G4double M2 = targetParticle->GetDefinition()->GetPDGMass(); |
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191 | G4double totalEnergy = E1 + E2; |
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192 | G4double pseudoMass = std::sqrt(totalEnergy*totalEnergy - P*P); |
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193 | // pseudoMass also = std::sqrt(M1*M1 + M2*M2 + 2*M2*E1) |
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194 | |
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195 | // Transform into centre of mass system |
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196 | |
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197 | G4double px = (M2/pseudoMass)*Px; |
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198 | G4double py = (M2/pseudoMass)*Py; |
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199 | G4double pz = (M2/pseudoMass)*Pz; |
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200 | G4double p = std::sqrt(px*px + py*py + pz*pz); |
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201 | |
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202 | if (verboseLevel > 1) { |
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203 | G4cout << " E1, M1 (GeV) " << E1/GeV << " " << M1/GeV << G4endl; |
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204 | G4cout << " E2, M2 (GeV) " << E2/GeV << " " << M2/GeV << G4endl; |
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205 | G4cout << " particle 1 momentum in CM " << px/GeV << " " << py/GeV << " " |
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206 | << pz/GeV << " " << p/GeV << G4endl; |
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207 | } |
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208 | |
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209 | // First scatter w.r.t. Z axis |
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210 | G4double phi = G4UniformRand()*twopi; |
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211 | G4double pxnew = p*std::sin(theta)*std::cos(phi); |
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212 | G4double pynew = p*std::sin(theta)*std::sin(phi); |
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213 | G4double pznew = p*std::cos(theta); |
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214 | |
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215 | // Rotate according to the direction of the incident particle |
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216 | if (px*px + py*py > 0) { |
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217 | G4double cost, sint, ph, cosp, sinp; |
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218 | cost = pz/p; |
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219 | sint = (std::sqrt(std::abs((1-cost)*(1+cost))) + std::sqrt(px*px+py*py)/p)/2; |
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220 | py < 0 ? ph = 3*halfpi : ph = halfpi; |
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221 | if (std::abs(px) > 0.000001*GeV) ph = std::atan2(py,px); |
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222 | cosp = std::cos(ph); |
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223 | sinp = std::sin(ph); |
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224 | px = (cost*cosp*pxnew - sinp*pynew + sint*cosp*pznew); |
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225 | py = (cost*sinp*pxnew + cosp*pynew + sint*sinp*pznew); |
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226 | pz = (-sint*pxnew + cost*pznew); |
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227 | // G4ThreeVector it(a,b,c); |
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228 | // p0->SetMomentum(it); |
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229 | // G4ThreeVector aTargetMom = theInitial - it; |
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230 | // targetParticle->SetMomentum(aTargetMom); |
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231 | } |
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232 | else { |
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233 | px = pxnew; |
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234 | py = pynew; |
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235 | pz = pznew; |
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236 | } |
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237 | |
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238 | if (verboseLevel > 1) { |
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239 | G4cout << " AFTER SCATTER..." << G4endl; |
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240 | G4cout << " particle 1 momentum in CM " << px/GeV << " " << py/GeV << " " |
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241 | << pz/GeV << " " << p/GeV << G4endl; |
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242 | } |
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243 | |
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244 | // Transform to lab system |
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245 | |
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246 | G4double E1pM2 = E1 + M2; |
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247 | G4double betaCM = P/E1pM2; |
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248 | G4double betaCMx = Px/E1pM2; |
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249 | G4double betaCMy = Py/E1pM2; |
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250 | G4double betaCMz = Pz/E1pM2; |
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251 | G4double gammaCM = E1pM2/std::sqrt(E1pM2*E1pM2 - P*P); |
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252 | |
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253 | if (verboseLevel > 1) { |
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254 | G4cout << " betaCM " << betaCMx << " " << betaCMy << " " |
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255 | << betaCMz << " " << betaCM << G4endl; |
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256 | G4cout << " gammaCM " << gammaCM << G4endl; |
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257 | } |
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258 | |
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259 | // Now following GLOREN... |
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260 | |
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261 | G4double BETA[5], PA[5], PB[5]; |
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262 | BETA[1] = -betaCMx; |
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263 | BETA[2] = -betaCMy; |
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264 | BETA[3] = -betaCMz; |
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265 | BETA[4] = gammaCM; |
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266 | |
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267 | //The incident particle... |
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268 | |
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269 | PA[1] = px; |
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270 | PA[2] = py; |
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271 | PA[3] = pz; |
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272 | PA[4] = std::sqrt(M1*M1 + p*p); |
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273 | |
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274 | G4double BETPA = BETA[1]*PA[1] + BETA[2]*PA[2] + BETA[3]*PA[3]; |
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275 | G4double BPGAM = (BETPA * BETA[4]/(BETA[4] + 1.) - PA[4]) * BETA[4]; |
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276 | |
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277 | PB[1] = PA[1] + BPGAM * BETA[1]; |
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278 | PB[2] = PA[2] + BPGAM * BETA[2]; |
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279 | PB[3] = PA[3] + BPGAM * BETA[3]; |
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280 | PB[4] = (PA[4] - BETPA) * BETA[4]; |
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281 | |
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282 | G4DynamicParticle* newP = new G4DynamicParticle; |
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283 | newP->SetDefinition(const_cast<G4ParticleDefinition *>(aParticle->GetDefinition())); |
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284 | newP->SetMomentum(G4ThreeVector(PB[1], PB[2], PB[3])); |
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285 | |
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286 | //The target particle... |
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287 | |
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288 | PA[1] = -px; |
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289 | PA[2] = -py; |
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290 | PA[3] = -pz; |
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291 | PA[4] = std::sqrt(M2*M2 + p*p); |
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292 | |
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293 | BETPA = BETA[1]*PA[1] + BETA[2]*PA[2] + BETA[3]*PA[3]; |
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294 | BPGAM = (BETPA * BETA[4]/(BETA[4] + 1.) - PA[4]) * BETA[4]; |
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295 | |
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296 | PB[1] = PA[1] + BPGAM * BETA[1]; |
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297 | PB[2] = PA[2] + BPGAM * BETA[2]; |
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298 | PB[3] = PA[3] + BPGAM * BETA[3]; |
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299 | PB[4] = (PA[4] - BETPA) * BETA[4]; |
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300 | |
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301 | targetParticle->SetMomentum(G4ThreeVector(PB[1], PB[2], PB[3])); |
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302 | |
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303 | if (verboseLevel > 1) { |
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304 | G4cout << " particle 1 momentum in LAB " |
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305 | << newP->GetMomentum()*(1./GeV) |
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306 | << " " << newP->GetTotalMomentum()/GeV << G4endl; |
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307 | G4cout << " particle 2 momentum in LAB " |
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308 | << targetParticle->GetMomentum()*(1./GeV) |
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309 | << " " << targetParticle->GetTotalMomentum()/GeV << G4endl; |
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310 | G4cout << " TOTAL momentum in LAB " |
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311 | << (newP->GetMomentum()+targetParticle->GetMomentum())*(1./GeV) |
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312 | << " " |
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313 | << (newP->GetMomentum()+targetParticle->GetMomentum()).mag()/GeV |
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314 | << G4endl; |
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315 | } |
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316 | |
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317 | theParticleChange.SetMomentumChange(newP->GetMomentumDirection()); |
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318 | theParticleChange.SetEnergyChange(newP->GetKineticEnergy()); |
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319 | delete newP; |
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320 | G4DynamicParticle* p1 = new G4DynamicParticle; |
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321 | p1->SetDefinition(targetParticle->GetDefinition()); |
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322 | p1->SetMomentum(targetParticle->GetMomentum()); |
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323 | theParticleChange.AddSecondary(p1); |
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324 | |
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325 | return &theParticleChange; |
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326 | } |
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327 | |
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328 | // end of file |
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