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 | // G4PionMinusAbsorptionAtRest physics process |
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27 | // Larry Felawka (TRIUMF), April 1998 |
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28 | //--------------------------------------------------------------------- |
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29 | |
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30 | #include "G4PionMinusAbsorptionAtRest.hh" |
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31 | #include "G4DynamicParticle.hh" |
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32 | #include "G4ParticleTypes.hh" |
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33 | #include "Randomize.hh" |
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34 | #include "G4HadronicProcessStore.hh" |
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35 | #include <string.h> |
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36 | #include <cmath> |
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37 | #include <stdio.h> |
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38 | |
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39 | #define MAX_SECONDARIES 100 |
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40 | |
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41 | // constructor |
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42 | |
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43 | G4PionMinusAbsorptionAtRest::G4PionMinusAbsorptionAtRest(const G4String& processName, |
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44 | G4ProcessType aType ) : |
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45 | G4VRestProcess (processName, aType), // initialization |
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46 | massPionMinus(G4PionMinus::PionMinus()->GetPDGMass()/GeV), |
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47 | pdefGamma(G4Gamma::Gamma()), |
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48 | pdefPionZero(G4PionZero::PionZero()), |
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49 | pdefPionMinus(G4PionMinus::PionMinus()), |
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50 | pdefProton(G4Proton::Proton()), |
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51 | pdefNeutron(G4Neutron::Neutron()), |
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52 | pdefDeuteron(G4Deuteron::Deuteron()), |
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53 | pdefTriton(G4Triton::Triton()), |
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54 | pdefAlpha(G4Alpha::Alpha()) |
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55 | { |
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56 | if (verboseLevel>0) { |
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57 | G4cout << GetProcessName() << " is created "<< G4endl; |
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58 | } |
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59 | SetProcessSubType(fHadronAtRest); |
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60 | pv = new G4GHEKinematicsVector [MAX_SECONDARIES+1]; |
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61 | eve = new G4GHEKinematicsVector [MAX_SECONDARIES]; |
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62 | gkin = new G4GHEKinematicsVector [MAX_SECONDARIES]; |
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63 | |
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64 | G4HadronicProcessStore::Instance()->RegisterExtraProcess(this); |
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65 | } |
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66 | |
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67 | // destructor |
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68 | |
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69 | G4PionMinusAbsorptionAtRest::~G4PionMinusAbsorptionAtRest() |
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70 | { |
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71 | G4HadronicProcessStore::Instance()->DeRegisterExtraProcess(this); |
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72 | delete [] pv; |
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73 | delete [] eve; |
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74 | delete [] gkin; |
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75 | } |
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76 | |
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77 | void G4PionMinusAbsorptionAtRest::PreparePhysicsTable(const G4ParticleDefinition& p) |
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78 | { |
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79 | G4HadronicProcessStore::Instance()->RegisterParticleForExtraProcess(this, &p); |
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80 | } |
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81 | |
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82 | void G4PionMinusAbsorptionAtRest::BuildPhysicsTable(const G4ParticleDefinition& p) |
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83 | { |
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84 | G4HadronicProcessStore::Instance()->PrintInfo(&p); |
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85 | } |
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86 | |
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87 | // methods............................................................................. |
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88 | |
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89 | G4bool G4PionMinusAbsorptionAtRest::IsApplicable( |
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90 | const G4ParticleDefinition& particle |
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91 | ) |
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92 | { |
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93 | return ( &particle == pdefPionMinus ); |
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94 | |
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95 | } |
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96 | |
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97 | // Warning - this method may be optimized away if made "inline" |
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98 | G4int G4PionMinusAbsorptionAtRest::GetNumberOfSecondaries() |
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99 | { |
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100 | return ( ngkine ); |
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101 | |
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102 | } |
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103 | |
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104 | // Warning - this method may be optimized away if made "inline" |
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105 | G4GHEKinematicsVector* G4PionMinusAbsorptionAtRest::GetSecondaryKinematics() |
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106 | { |
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107 | return ( &gkin[0] ); |
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108 | |
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109 | } |
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110 | |
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111 | G4double G4PionMinusAbsorptionAtRest::AtRestGetPhysicalInteractionLength( |
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112 | const G4Track& track, |
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113 | G4ForceCondition* condition |
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114 | ) |
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115 | { |
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116 | // beggining of tracking |
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117 | ResetNumberOfInteractionLengthLeft(); |
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118 | |
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119 | // condition is set to "Not Forced" |
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120 | *condition = NotForced; |
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121 | |
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122 | // get mean life time |
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123 | currentInteractionLength = GetMeanLifeTime(track, condition); |
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124 | |
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125 | if ((currentInteractionLength <0.0) || (verboseLevel>2)){ |
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126 | G4cout << "G4PionMinusAbsorptionAtRestProcess::AtRestGetPhysicalInteractionLength "; |
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127 | G4cout << "[ " << GetProcessName() << "]" <<G4endl; |
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128 | track.GetDynamicParticle()->DumpInfo(); |
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129 | G4cout << " in Material " << track.GetMaterial()->GetName() <<G4endl; |
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130 | G4cout << "MeanLifeTime = " << currentInteractionLength/ns << "[ns]" <<G4endl; |
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131 | } |
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132 | |
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133 | return theNumberOfInteractionLengthLeft * currentInteractionLength; |
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134 | |
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135 | } |
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136 | |
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137 | G4VParticleChange* G4PionMinusAbsorptionAtRest::AtRestDoIt( |
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138 | const G4Track& track, |
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139 | const G4Step& |
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140 | ) |
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141 | // |
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142 | // Handles PionMinuss at rest; a PionMinus can either create secondaries or |
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143 | // do nothing (in which case it should be sent back to decay-handling |
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144 | // section |
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145 | // |
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146 | { |
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147 | |
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148 | // Initialize ParticleChange |
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149 | // all members of G4VParticleChange are set to equal to |
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150 | // corresponding member in G4Track |
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151 | |
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152 | aParticleChange.Initialize(track); |
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153 | |
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154 | // Store some global quantities that depend on current material and particle |
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155 | |
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156 | globalTime = track.GetGlobalTime()/s; |
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157 | G4Material * aMaterial = track.GetMaterial(); |
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158 | const G4int numberOfElements = aMaterial->GetNumberOfElements(); |
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159 | const G4ElementVector* theElementVector = aMaterial->GetElementVector(); |
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160 | |
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161 | const G4double* theAtomicNumberDensity = aMaterial->GetAtomicNumDensityVector(); |
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162 | G4double normalization = 0; |
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163 | for ( G4int i1=0; i1 < numberOfElements; i1++ ) |
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164 | { |
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165 | normalization += theAtomicNumberDensity[i1] ; // change when nucleon specific |
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166 | // probabilities are included. |
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167 | } |
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168 | G4double runningSum= 0.; |
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169 | G4double random = G4UniformRand()*normalization; |
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170 | for ( G4int i2=0; i2 < numberOfElements; i2++ ) |
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171 | { |
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172 | runningSum += theAtomicNumberDensity[i2]; // change when nucleon specific |
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173 | // probabilities are included. |
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174 | if (random<=runningSum) |
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175 | { |
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176 | targetCharge = G4double((*theElementVector)[i2]->GetZ()); |
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177 | targetAtomicMass = (*theElementVector)[i2]->GetN(); |
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178 | } |
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179 | } |
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180 | if (random>runningSum) |
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181 | { |
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182 | targetCharge = G4double((*theElementVector)[numberOfElements-1]->GetZ()); |
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183 | targetAtomicMass = (*theElementVector)[numberOfElements-1]->GetN(); |
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184 | |
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185 | } |
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186 | |
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187 | if (verboseLevel>1) { |
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188 | G4cout << "G4PionMinusAbsorptionAtRest::AtRestDoIt is invoked " <<G4endl; |
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189 | } |
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190 | |
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191 | G4ParticleMomentum momentum; |
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192 | G4float localtime; |
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193 | |
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194 | G4ThreeVector position = track.GetPosition(); |
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195 | |
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196 | GenerateSecondaries(); // Generate secondaries |
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197 | |
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198 | aParticleChange.SetNumberOfSecondaries( ngkine ); |
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199 | |
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200 | for ( G4int isec = 0; isec < ngkine; isec++ ) { |
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201 | G4DynamicParticle* aNewParticle = new G4DynamicParticle; |
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202 | aNewParticle->SetDefinition( gkin[isec].GetParticleDef() ); |
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203 | aNewParticle->SetMomentum( gkin[isec].GetMomentum() * GeV ); |
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204 | |
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205 | localtime = globalTime + gkin[isec].GetTOF(); |
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206 | |
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207 | G4Track* aNewTrack = new G4Track( aNewParticle, localtime*s, position ); |
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208 | aNewTrack->SetTouchableHandle(track.GetTouchableHandle()); |
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209 | aParticleChange.AddSecondary( aNewTrack ); |
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210 | |
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211 | } |
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212 | |
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213 | aParticleChange.ProposeLocalEnergyDeposit( 0.0*GeV ); |
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214 | |
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215 | aParticleChange.ProposeTrackStatus(fStopAndKill); // Kill the incident PionMinus |
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216 | |
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217 | // clear InteractionLengthLeft |
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218 | |
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219 | ResetNumberOfInteractionLengthLeft(); |
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220 | |
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221 | return &aParticleChange; |
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222 | |
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223 | } |
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224 | |
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225 | |
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226 | void G4PionMinusAbsorptionAtRest::GenerateSecondaries() |
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227 | { |
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228 | static G4int index; |
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229 | static G4int l; |
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230 | static G4int nopt; |
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231 | static G4int i; |
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232 | static G4ParticleDefinition* jnd; |
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233 | |
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234 | for (i = 1; i <= MAX_SECONDARIES; ++i) { |
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235 | pv[i].SetZero(); |
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236 | } |
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237 | |
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238 | ngkine = 0; // number of generated secondary particles |
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239 | ntot = 0; |
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240 | result.SetZero(); |
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241 | result.SetMass( massPionMinus ); |
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242 | result.SetKineticEnergyAndUpdate( 0. ); |
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243 | result.SetTOF( 0. ); |
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244 | result.SetParticleDef( pdefPionMinus ); |
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245 | |
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246 | PionMinusAbsorption(&nopt); |
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247 | |
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248 | // *** CHECK WHETHER THERE ARE NEW PARTICLES GENERATED *** |
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249 | if (ntot != 0 || result.GetParticleDef() != pdefPionMinus) { |
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250 | // *** CURRENT PARTICLE IS NOT THE SAME AS IN THE BEGINNING OR/AND *** |
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251 | // *** ONE OR MORE SECONDARIES HAVE BEEN GENERATED *** |
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252 | |
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253 | // --- INITIAL PARTICLE TYPE HAS BEEN CHANGED ==> PUT NEW TYPE ON --- |
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254 | // --- THE GEANT TEMPORARY STACK --- |
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255 | |
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256 | // --- PUT PARTICLE ON THE STACK --- |
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257 | gkin[0] = result; |
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258 | gkin[0].SetTOF( result.GetTOF() * 5e-11 ); |
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259 | ngkine = 1; |
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260 | |
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261 | // --- ALL QUANTITIES ARE TAKEN FROM THE GHEISHA STACK WHERE THE --- |
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262 | // --- CONVENTION IS THE FOLLOWING --- |
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263 | |
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264 | // --- ONE OR MORE SECONDARIES HAVE BEEN GENERATED --- |
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265 | for (l = 1; l <= ntot; ++l) { |
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266 | index = l - 1; |
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267 | jnd = eve[index].GetParticleDef(); |
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268 | |
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269 | // --- ADD PARTICLE TO THE STACK IF STACK NOT YET FULL --- |
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270 | if (ngkine < MAX_SECONDARIES) { |
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271 | gkin[ngkine] = eve[index]; |
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272 | gkin[ngkine].SetTOF( eve[index].GetTOF() * 5e-11 ); |
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273 | ++ngkine; |
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274 | } |
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275 | } |
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276 | } |
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277 | else { |
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278 | // --- NO SECONDARIES GENERATED AND PARTICLE IS STILL THE SAME --- |
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279 | // --- ==> COPY EVERYTHING BACK IN THE CURRENT GEANT STACK --- |
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280 | ngkine = 0; |
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281 | ntot = 0; |
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282 | globalTime += result.GetTOF() * G4float(5e-11); |
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283 | } |
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284 | |
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285 | // --- LIMIT THE VALUE OF NGKINE IN CASE OF OVERFLOW --- |
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286 | ngkine = G4int(std::min(ngkine,G4int(MAX_SECONDARIES))); |
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287 | |
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288 | } // GenerateSecondaries |
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289 | |
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290 | |
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291 | void G4PionMinusAbsorptionAtRest::PionMinusAbsorption(G4int *nopt) |
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292 | { |
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293 | static G4int i; |
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294 | static G4int nt, nbl; |
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295 | static G4float ran, tex; |
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296 | static G4int isw; |
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297 | static G4float ran2, tof1, ekin; |
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298 | static G4float ekin1, ekin2, black; |
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299 | static G4float pnrat; |
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300 | static G4ParticleDefinition* ipa1; |
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301 | static G4ParticleDefinition* inve; |
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302 | |
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303 | // *** CHARGED PION ABSORPTION BY A NUCLEUS *** |
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304 | // *** NVE 04-MAR-1988 CERN GENEVA *** |
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305 | |
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306 | // ORIGIN : H.FESEFELDT (09-JULY-1987) |
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307 | |
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308 | // PANOFSKY RATIO (PI- P --> N PI0/PI- P --> N GAMMA) = 3/2 |
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309 | // FOR CAPTURE ON PROTON (HYDROGEN), |
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310 | // STAR PRODUCTION FOR HEAVIER ELEMENTS |
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311 | |
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312 | pv[1].SetZero(); |
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313 | pv[1].SetMass( massPionMinus ); |
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314 | pv[1].SetKineticEnergyAndUpdate( 0. ); |
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315 | pv[1].SetTOF( result.GetTOF() ); |
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316 | pv[1].SetParticleDef( result.GetParticleDef() ); |
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317 | if (targetAtomicMass <= G4float(1.5)) { |
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318 | ran = G4UniformRand(); |
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319 | isw = 1; |
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320 | if (ran < G4float(.33)) { |
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321 | isw = 2; |
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322 | } |
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323 | *nopt = isw; |
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324 | ran = G4UniformRand(); |
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325 | tof1 = std::log(ran) * G4float(-25.); |
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326 | tof1 *= G4float(20.); |
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327 | if (isw != 1) { |
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328 | pv[2].SetZero(); |
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329 | pv[2].SetMass( 0. ); |
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330 | pv[2].SetKineticEnergyAndUpdate( .02 ); |
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331 | pv[2].SetTOF( result.GetTOF() + tof1 ); |
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332 | pv[2].SetParticleDef( pdefGamma ); |
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333 | } |
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334 | else { |
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335 | pv[2] = pv[1]; |
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336 | pv[2].SetTOF( result.GetTOF() + tof1 ); |
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337 | pv[2].SetParticleDef( pdefPionZero ); |
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338 | } |
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339 | result = pv[2]; |
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340 | } |
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341 | else { |
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342 | // ** |
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343 | // ** STAR PRODUCTION FOR PION ABSORPTION IN HEAVY ELEMENTS |
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344 | // ** |
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345 | evapEnergy1 = G4float(.0135); |
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346 | evapEnergy3 = G4float(.0058); |
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347 | nt = 1; |
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348 | tex = evapEnergy1; |
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349 | black = std::log(targetAtomicMass) * G4float(.5); |
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350 | Poisso(black, &nbl); |
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351 | if (nbl <= 0) { |
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352 | nbl = 1; |
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353 | } |
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354 | if (nt + nbl > (MAX_SECONDARIES - 2)) { |
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355 | nbl = (MAX_SECONDARIES - 2) - nt; |
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356 | } |
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357 | ekin = tex / nbl; |
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358 | ekin2 = G4float(0.); |
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359 | for (i = 1; i <= nbl; ++i) { |
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360 | if (nt == (MAX_SECONDARIES - 2)) { |
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361 | continue; |
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362 | } |
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363 | ran2 = G4UniformRand(); |
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364 | ekin1 = -G4double(ekin) * std::log(ran2); |
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365 | ekin2 += ekin1; |
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366 | ipa1 = pdefNeutron; |
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367 | pnrat = G4float(1.) - targetCharge / targetAtomicMass; |
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368 | if (G4UniformRand() > pnrat) { |
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369 | ipa1 = pdefProton; |
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370 | } |
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371 | ++nt; |
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372 | pv[nt].SetZero(); |
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373 | pv[nt].SetMass( ipa1->GetPDGMass()/GeV ); |
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374 | pv[nt].SetKineticEnergyAndUpdate( ekin1 ); |
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375 | pv[nt].SetTOF( 2. ); |
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376 | pv[nt].SetParticleDef( ipa1 ); |
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377 | if (ekin2 > tex) { |
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378 | break; |
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379 | } |
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380 | } |
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381 | tex = evapEnergy3; |
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382 | black = std::log(targetAtomicMass) * G4float(.5); |
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383 | Poisso(black, &nbl); |
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384 | if (nt + nbl > (MAX_SECONDARIES - 2)) { |
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385 | nbl = (MAX_SECONDARIES - 2) - nt; |
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386 | } |
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387 | if (nbl <= 0) { |
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388 | nbl = 1; |
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389 | } |
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390 | ekin = tex / nbl; |
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391 | ekin2 = G4float(0.); |
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392 | for (i = 1; i <= nbl; ++i) { |
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393 | if (nt == (MAX_SECONDARIES - 2)) { |
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394 | continue; |
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395 | } |
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396 | ran2 = G4UniformRand(); |
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397 | ekin1 = -G4double(ekin) * std::log(ran2); |
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398 | ekin2 += ekin1; |
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399 | ++nt; |
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400 | ran = G4UniformRand(); |
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401 | inve= pdefDeuteron; |
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402 | if (ran > G4float(.6)) { |
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403 | inve = pdefTriton; |
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404 | } |
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405 | if (ran > G4float(.9)) { |
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406 | inve = pdefAlpha; |
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407 | } |
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408 | pv[nt].SetZero(); |
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409 | pv[nt].SetMass( inve->GetPDGMass()/GeV ); |
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410 | pv[nt].SetKineticEnergyAndUpdate( ekin1 ); |
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411 | pv[nt].SetTOF( 2. ); |
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412 | pv[nt].SetParticleDef( inve ); |
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413 | if (ekin2 > tex) { |
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414 | break; |
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415 | } |
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416 | } |
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417 | // ** |
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418 | // ** STORE ON EVENT COMMON |
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419 | // ** |
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420 | ran = G4UniformRand(); |
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421 | tof1 = std::log(ran) * G4float(-25.); |
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422 | tof1 *= G4float(20.); |
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423 | for (i = 2; i <= nt; ++i) { |
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424 | pv[i].SetTOF( result.GetTOF() + tof1 ); |
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425 | } |
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426 | result = pv[2]; |
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427 | for (i = 3; i <= nt; ++i) { |
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428 | if (ntot >= MAX_SECONDARIES) { |
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429 | break; |
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430 | } |
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431 | eve[ntot++] = pv[i]; |
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432 | } |
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433 | } |
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434 | |
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435 | } // PionMinusAbsorption |
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436 | |
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437 | |
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438 | void G4PionMinusAbsorptionAtRest::Poisso(G4float xav, G4int *iran) |
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439 | { |
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440 | static G4int i; |
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441 | static G4float r, p1, p2, p3; |
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442 | static G4int mm; |
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443 | static G4float rr, ran, rrr, ran1; |
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444 | |
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445 | // *** GENERATION OF POISSON DISTRIBUTION *** |
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446 | // *** NVE 16-MAR-1988 CERN GENEVA *** |
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447 | // ORIGIN : H.FESEFELDT (27-OCT-1983) |
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448 | |
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449 | // --- USE NORMAL DISTRIBUTION FOR <X> > 9.9 --- |
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450 | if (xav > G4float(9.9)) { |
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451 | // ** NORMAL DISTRIBUTION WITH SIGMA**2 = <X> |
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452 | Normal(&ran1); |
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453 | ran1 = xav + ran1 * std::sqrt(xav); |
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454 | *iran = G4int(ran1); |
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455 | if (*iran < 0) { |
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456 | *iran = 0; |
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457 | } |
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458 | } |
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459 | else { |
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460 | mm = G4int(xav * G4float(5.)); |
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461 | *iran = 0; |
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462 | if (mm > 0) { |
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463 | r = std::exp(-G4double(xav)); |
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464 | ran1 = G4UniformRand(); |
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465 | if (ran1 > r) { |
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466 | rr = r; |
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467 | for (i = 1; i <= mm; ++i) { |
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468 | ++(*iran); |
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469 | if (i <= 5) { |
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470 | rrr = std::pow(xav, G4float(i)) / NFac(i); |
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471 | } |
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472 | // ** STIRLING' S FORMULA FOR LARGE NUMBERS |
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473 | if (i > 5) { |
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474 | rrr = std::exp(i * std::log(xav) - |
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475 | (i + G4float(.5)) * std::log(i * G4float(1.)) + |
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476 | i - G4float(.9189385)); |
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477 | } |
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478 | rr += r * rrr; |
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479 | if (ran1 <= rr) { |
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480 | break; |
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481 | } |
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482 | } |
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483 | } |
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484 | } |
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485 | else { |
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486 | // ** FOR VERY SMALL XAV TRY IRAN=1,2,3 |
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487 | p1 = xav * std::exp(-G4double(xav)); |
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488 | p2 = xav * p1 / G4float(2.); |
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489 | p3 = xav * p2 / G4float(3.); |
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490 | ran = G4UniformRand(); |
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491 | if (ran >= p3) { |
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492 | if (ran >= p2) { |
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493 | if (ran >= p1) { |
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494 | *iran = 0; |
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495 | } |
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496 | else { |
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497 | *iran = 1; |
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498 | } |
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499 | } |
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500 | else { |
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501 | *iran = 2; |
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502 | } |
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503 | } |
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504 | else { |
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505 | *iran = 3; |
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506 | } |
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507 | } |
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508 | } |
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509 | |
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510 | } // Poisso |
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511 | |
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512 | |
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513 | G4int G4PionMinusAbsorptionAtRest::NFac(G4int n) |
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514 | { |
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515 | G4int ret_val; |
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516 | |
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517 | static G4int i, m; |
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518 | |
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519 | // *** NVE 16-MAR-1988 CERN GENEVA *** |
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520 | // ORIGIN : H.FESEFELDT (27-OCT-1983) |
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521 | |
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522 | ret_val = 1; |
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523 | m = n; |
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524 | if (m > 1) { |
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525 | if (m > 10) { |
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526 | m = 10; |
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527 | } |
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528 | for (i = 2; i <= m; ++i) { |
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529 | ret_val *= i; |
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530 | } |
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531 | } |
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532 | return ret_val; |
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533 | |
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534 | } // NFac |
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535 | |
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536 | |
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537 | void G4PionMinusAbsorptionAtRest::Normal(G4float *ran) |
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538 | { |
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539 | static G4int i; |
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540 | |
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541 | // *** NVE 14-APR-1988 CERN GENEVA *** |
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542 | // ORIGIN : H.FESEFELDT (27-OCT-1983) |
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543 | |
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544 | *ran = G4float(-6.); |
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545 | for (i = 1; i <= 12; ++i) { |
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546 | *ran += G4UniformRand(); |
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547 | } |
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548 | |
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549 | } // Normal |
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