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 | // $Id: G4MscModel71.cc,v 1.5 2007/05/22 17:34:36 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-01-patch-02 $ |
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28 | // |
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29 | // ------------------------------------------------------------------- |
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30 | // |
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31 | // GEANT4 Class file |
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32 | // |
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33 | // |
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34 | // File name: G4MscModel71 |
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35 | // |
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36 | // Author: Laszlo Urban |
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37 | // |
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38 | // Creation date: 03.03.2001 |
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39 | // |
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40 | // Modifications: |
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41 | // |
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42 | // 27-03-03 Move model part from G4MultipleScattering (V.Ivanchenko) |
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43 | // 23-05-03 important change in angle distribution for muons/hadrons |
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44 | // the central part now is similar to the Highland parametrization + |
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45 | // minor correction in angle sampling algorithm (for all particles) |
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46 | // (L.Urban) |
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47 | // 30-05-03 misprint in SampleCosineTheta corrected(L.Urban) |
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48 | // 27-03-03 Rename (V.Ivanchenko) |
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49 | // 05-08-03 angle distribution has been modified (L.Urban) |
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50 | // 06-11-03 precision problems solved for high energy (PeV) particles |
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51 | // change in the tail of the angular distribution |
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52 | // highKinEnergy is set to 100 PeV (L.Urban) |
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53 | // |
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54 | // 10-11-03 highKinEnergy is set back to 100 TeV, some tail tuning + |
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55 | // cleaning (L.Urban) |
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56 | // 26-11-03 correction in TrueStepLength : |
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57 | // trueLength <= currentRange (L.Urban) |
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58 | // 01-03-04 signature changed in SampleCosineTheta, |
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59 | // energy dependence calculations has been simplified, |
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60 | // 11-03-04 corrections in GeomPathLength,TrueStepLength, |
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61 | // SampleCosineTheta |
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62 | // 23-04-04 true -> geom and geom -> true transformation has been |
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63 | // rewritten, changes in the angular distribution (L.Urban) |
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64 | // 19-07-04 correction in SampleCosineTheta in order to avoid |
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65 | // num. precision problems at high energy/small step(L.Urban) |
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66 | // 17-08-04 changes in the angle distribution (slightly modified |
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67 | // Highland formula for the width of the central part, |
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68 | // changes in the numerical values of some other parameters) |
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69 | // ---> approximately step independent distribution (L.Urban) |
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70 | // 21-09-04 change in the tail of the angular distribution (L.Urban) |
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71 | // |
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72 | // 03-11-04 precision problem for very high energy ions and small stepsize |
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73 | // solved in SampleCosineTheta (L.Urban). |
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74 | // 15-04-05 optimize internal interface - add SampleSecondaries method (V.Ivanchenko) |
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75 | // 03-10-05 Model is freezed with the name McsModel71 (V.Ivanchenko) |
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76 | // 17-02-06 Save table of transport cross sections not mfp (V.Ivanchenko) |
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77 | // |
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78 | |
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79 | // Class Description: |
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80 | // |
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81 | // Implementation of the model of multiple scattering based on |
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82 | // H.W.Lewis Phys Rev 78 (1950) 526 and others |
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83 | |
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84 | // ------------------------------------------------------------------- |
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85 | // |
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86 | |
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87 | |
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88 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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89 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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90 | |
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91 | #include "G4MscModel71.hh" |
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92 | #include "Randomize.hh" |
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93 | #include "G4Electron.hh" |
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94 | #include "G4LossTableManager.hh" |
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95 | #include "G4PhysicsTable.hh" |
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96 | #include "G4ParticleChangeForMSC.hh" |
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97 | #include "G4TransportationManager.hh" |
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98 | #include "G4Navigator.hh" |
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99 | |
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100 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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101 | |
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102 | using namespace std; |
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103 | |
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104 | G4MscModel71::G4MscModel71(G4double& m_dtrl, G4double& m_NuclCorrPar, |
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105 | G4double& m_FactPar, G4double& m_factail, |
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106 | G4bool& m_samplez, const G4String& nam) |
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107 | : G4VEmModel(nam), |
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108 | taubig(8.0), |
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109 | tausmall(1.e-20), |
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110 | taulim(1.e-6), |
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111 | dtrl(m_dtrl), |
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112 | NuclCorrPar (m_NuclCorrPar), |
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113 | FactPar(m_FactPar), |
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114 | factail(m_factail), |
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115 | samplez(m_samplez), |
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116 | isInitialized(false) |
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117 | { |
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118 | stepmin = 1.e-6*mm; |
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119 | currentRange = 0. ; |
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120 | } |
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121 | |
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122 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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123 | |
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124 | G4MscModel71::~G4MscModel71() |
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125 | {} |
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126 | |
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127 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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128 | |
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129 | void G4MscModel71::Initialise(const G4ParticleDefinition* p, |
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130 | const G4DataVector&) |
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131 | { |
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132 | if(isInitialized) return; |
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133 | // set values of some data members |
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134 | sigmafactor = twopi*classic_electr_radius*classic_electr_radius; |
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135 | particle = p; |
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136 | mass = particle->GetPDGMass(); |
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137 | charge = particle->GetPDGCharge()/eplus; |
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138 | b = 1. ; |
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139 | xsi = 3.00 ; |
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140 | |
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141 | if(pParticleChange) |
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142 | fParticleChange = reinterpret_cast<G4ParticleChangeForMSC*>(pParticleChange); |
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143 | else |
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144 | fParticleChange = new G4ParticleChangeForMSC(); |
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145 | |
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146 | navigator = G4TransportationManager::GetTransportationManager() |
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147 | ->GetNavigatorForTracking(); |
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148 | } |
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149 | |
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150 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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151 | |
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152 | G4double G4MscModel71::ComputeCrossSectionPerAtom( |
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153 | const G4ParticleDefinition* part, |
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154 | G4double KineticEnergy, |
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155 | G4double AtomicNumber, |
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156 | G4double AtomicWeight, |
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157 | G4double, |
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158 | G4double) |
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159 | { |
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160 | const G4double epsfactor = 2.*electron_mass_c2*electron_mass_c2* |
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161 | Bohr_radius*Bohr_radius/(hbarc*hbarc); |
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162 | const G4double epsmin = 1.e-4 , epsmax = 1.e10; |
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163 | |
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164 | const G4double Zdat[15] = { 4., 6.,13.,20.,26.,29.,32.,38.,47., |
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165 | 50.,56.,64.,74.,79.,82. }; |
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166 | |
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167 | const G4double Tdat[23] = {0.0001*MeV,0.0002*MeV,0.0004*MeV,0.0007*MeV, |
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168 | 0.001*MeV,0.002*MeV,0.004*MeV,0.007*MeV, |
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169 | 0.01*MeV,0.02*MeV,0.04*MeV,0.07*MeV, |
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170 | 0.1*MeV,0.2*MeV,0.4*MeV,0.7*MeV, |
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171 | 1.*MeV,2.*MeV,4.*MeV,7.*MeV,10.*MeV,20.*MeV, |
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172 | 10000.0*MeV}; |
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173 | |
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174 | // corr. factors for e-/e+ lambda |
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175 | G4double celectron[15][23] = |
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176 | {{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054, |
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177 | 1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111, |
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178 | 1.112,1.108,1.100,1.093,1.089,1.087,0.7235 }, |
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179 | {1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051, |
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180 | 1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108, |
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181 | 1.109,1.105,1.097,1.090,1.086,1.082,0.7925 }, |
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182 | {2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156, |
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183 | 1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132, |
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184 | 1.131,1.124,1.113,1.104,1.099,1.098,0.9147 }, |
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185 | {3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236, |
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186 | 1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113, |
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187 | 1.112,1.105,1.096,1.089,1.085,1.098,0.9700 }, |
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188 | {6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265, |
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189 | 1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073, |
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190 | 1.073,1.070,1.064,1.059,1.056,1.056,1.0022 }, |
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191 | {9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330, |
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192 | 1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074, |
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193 | 1.074,1.070,1.063,1.059,1.056,1.052,1.0158 }, |
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194 | {11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386, |
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195 | 1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069, |
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196 | 1.068,1.064,1.059,1.054,1.051,1.050,1.0284 }, |
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197 | {18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439, |
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198 | 1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039, |
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199 | 1.039,1.037,1.034,1.031,1.030,1.036,1.0515 }, |
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200 | {18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631, |
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201 | 1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033, |
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202 | 1.031,1.028,1.024,1.022,1.021,1.024,1.0834 }, |
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203 | {14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669, |
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204 | 1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022, |
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205 | 1.020,1.017,1.015,1.013,1.013,1.020,1.0937 }, |
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206 | {14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720, |
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207 | 1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997, |
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208 | 0.995,0.993,0.993,0.993,0.993,1.011,1.1140 }, |
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209 | {22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855, |
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210 | 1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976, |
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211 | 0.974,0.972,0.973,0.974,0.975,0.987,1.1410 }, |
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212 | {50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059, |
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213 | 1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954, |
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214 | 0.950,0.947,0.949,0.952,0.954,0.963,1.1750 }, |
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215 | {65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182, |
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216 | 1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947, |
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217 | 0.941,0.938,0.940,0.944,0.946,0.954,1.1922 }, |
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218 | {55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239, |
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219 | 1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939, |
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220 | 0.933,0.930,0.933,0.936,0.939,0.949,1.2026 }}; |
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221 | G4double cpositron[15][23] = { |
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222 | {2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110, |
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223 | 1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131, |
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224 | 1.131,1.126,1.117,1.108,1.103,1.100,0.7235 }, |
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225 | {3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145, |
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226 | 1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137, |
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227 | 1.138,1.132,1.122,1.113,1.108,1.102,0.7925 }, |
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228 | {7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451, |
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229 | 1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205, |
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230 | 1.203,1.190,1.173,1.159,1.151,1.145,0.9147 }, |
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231 | {9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715, |
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232 | 1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228, |
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233 | 1.225,1.210,1.191,1.175,1.166,1.174,0.9700 }, |
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234 | {17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820, |
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235 | 1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219, |
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236 | 1.217,1.203,1.184,1.169,1.160,1.151,1.0022 }, |
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237 | {24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996, |
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238 | 1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241, |
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239 | 1.237,1.222,1.201,1.184,1.174,1.159,1.0158 }, |
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240 | {23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155, |
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241 | 1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256, |
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242 | 1.252,1.234,1.212,1.194,1.183,1.170,1.0284 }, |
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243 | {22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348, |
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244 | 2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258, |
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245 | 1.254,1.237,1.214,1.195,1.185,1.179,1.0515 }, |
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246 | {33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808, |
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247 | 2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320, |
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248 | 1.312,1.288,1.258,1.235,1.221,1.205,1.0834 }, |
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249 | {32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917, |
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250 | 2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327, |
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251 | 1.320,1.294,1.264,1.240,1.226,1.214,1.0937 }, |
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252 | {29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066, |
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253 | 2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336, |
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254 | 1.328,1.302,1.270,1.245,1.231,1.233,1.1140 }, |
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255 | {38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498, |
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256 | 2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371, |
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257 | 1.361,1.330,1.294,1.267,1.251,1.239,1.1410 }, |
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258 | {49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155, |
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259 | 3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423, |
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260 | 1.409,1.372,1.330,1.298,1.280,1.258,1.1750 }, |
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261 | {59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407, |
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262 | 3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459, |
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263 | 1.442,1.400,1.354,1.319,1.299,1.272,1.1922 }, |
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264 | {56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542, |
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265 | 3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474, |
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266 | 1.456,1.412,1.364,1.328,1.307,1.282,1.2026 }}; |
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267 | |
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268 | G4double sigma; |
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269 | if (part != particle ) { |
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270 | particle = part; |
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271 | mass = particle->GetPDGMass(); |
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272 | charge = particle->GetPDGCharge()/eplus; |
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273 | } |
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274 | |
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275 | G4double Z23 = 2.*log(AtomicNumber)/3.; Z23 = exp(Z23); |
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276 | |
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277 | // correction if particle .ne. e-/e+ |
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278 | // compute equivalent kinetic energy |
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279 | // lambda depends on p*beta .... |
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280 | |
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281 | G4double eKineticEnergy = KineticEnergy; |
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282 | |
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283 | if((particle->GetParticleName() != "e-") && |
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284 | (particle->GetParticleName() != "e+") ) |
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285 | { |
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286 | G4double TAU = KineticEnergy/mass ; |
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287 | G4double c = mass*TAU*(TAU+2.)/(electron_mass_c2*(TAU+1.)) ; |
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288 | G4double w = c-2. ; |
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289 | G4double tau = 0.5*(w+sqrt(w*w+4.*c)) ; |
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290 | eKineticEnergy = electron_mass_c2*tau ; |
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291 | } |
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292 | |
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293 | G4double ChargeSquare = charge*charge; |
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294 | |
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295 | G4double eTotalEnergy = eKineticEnergy + electron_mass_c2 ; |
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296 | G4double beta2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2) |
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297 | /(eTotalEnergy*eTotalEnergy); |
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298 | G4double bg2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2) |
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299 | /(electron_mass_c2*electron_mass_c2); |
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300 | |
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301 | G4double eps = epsfactor*bg2/Z23; |
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302 | |
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303 | if (eps<epsmin) sigma = 2.*eps*eps; |
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304 | else if(eps<epsmax) sigma = log(1.+2.*eps)-2.*eps/(1.+2.*eps); |
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305 | else sigma = log(2.*eps)-1.+1./eps; |
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306 | |
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307 | sigma *= ChargeSquare*AtomicNumber*AtomicNumber/(beta2*bg2); |
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308 | |
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309 | // nuclear size effect correction for high energy |
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310 | // ( a simple approximation at present) |
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311 | G4double corrnuclsize,a,w1,w2,w; |
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312 | |
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313 | G4double x0 = 1. - NuclCorrPar*mass/(KineticEnergy* |
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314 | exp(log(AtomicWeight/(g/mole))/3.)); |
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315 | if ( x0 < -1. || eKineticEnergy <= 10.*MeV) |
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316 | { |
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317 | x0 = -1.; |
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318 | corrnuclsize = 1.; |
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319 | } |
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320 | else |
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321 | { |
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322 | a = 1.+1./eps; |
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323 | if (eps > epsmax) w1=log(2.*eps)+1./eps-3./(8.*eps*eps); |
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324 | else w1=log((a+1.)/(a-1.))-2./(a+1.); |
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325 | w = 1./((1.-x0)*eps); |
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326 | if (w < epsmin) w2=-log(w)-1.+2.*w-1.5*w*w; |
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327 | else w2 = log((a-x0)/(a-1.))-(1.-x0)/(a-x0); |
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328 | corrnuclsize = w1/w2; |
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329 | corrnuclsize = exp(-FactPar*mass/KineticEnergy)* |
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330 | (corrnuclsize-1.)+1.; |
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331 | } |
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332 | |
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333 | // interpolate in AtomicNumber and beta2 |
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334 | // get bin number in Z |
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335 | G4int iZ = 14; |
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336 | while ((iZ>=0)&&(Zdat[iZ]>=AtomicNumber)) iZ -= 1; |
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337 | if (iZ==14) iZ = 13; |
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338 | if (iZ==-1) iZ = 0 ; |
---|
339 | |
---|
340 | G4double Z1 = Zdat[iZ]; |
---|
341 | G4double Z2 = Zdat[iZ+1]; |
---|
342 | G4double ratZ = (AtomicNumber-Z1)/(Z2-Z1); |
---|
343 | |
---|
344 | // get bin number in T (beta2) |
---|
345 | G4int iT = 22; |
---|
346 | while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1; |
---|
347 | if(iT==22) iT = 21; |
---|
348 | if(iT==-1) iT = 0 ; |
---|
349 | |
---|
350 | // calculate betasquare values |
---|
351 | G4double T = Tdat[iT], E = T + electron_mass_c2; |
---|
352 | G4double b2small = T*(E+electron_mass_c2)/(E*E); |
---|
353 | T = Tdat[iT+1]; E = T + electron_mass_c2; |
---|
354 | G4double b2big = T*(E+electron_mass_c2)/(E*E); |
---|
355 | G4double ratb2 = (beta2-b2small)/(b2big-b2small); |
---|
356 | G4double c1,c2,cc1,cc2,corr; |
---|
357 | if (charge < 0.) |
---|
358 | { |
---|
359 | c1 = celectron[iZ][iT]; |
---|
360 | c2 = celectron[iZ+1][iT]; |
---|
361 | cc1 = c1+ratZ*(c2-c1); |
---|
362 | |
---|
363 | c1 = celectron[iZ][iT+1]; |
---|
364 | c2 = celectron[iZ+1][iT+1]; |
---|
365 | cc2 = c1+ratZ*(c2-c1); |
---|
366 | |
---|
367 | corr = cc1+ratb2*(cc2-cc1); |
---|
368 | sigma /= corr; |
---|
369 | } |
---|
370 | |
---|
371 | if (charge > 0.) |
---|
372 | { |
---|
373 | c1 = cpositron[iZ][iT]; |
---|
374 | c2 = cpositron[iZ+1][iT]; |
---|
375 | cc1 = c1+ratZ*(c2-c1); |
---|
376 | |
---|
377 | c1 = cpositron[iZ][iT+1]; |
---|
378 | c2 = cpositron[iZ+1][iT+1]; |
---|
379 | cc2 = c1+ratZ*(c2-c1); |
---|
380 | |
---|
381 | corr = cc1+ratb2*(cc2-cc1); |
---|
382 | sigma /= corr; |
---|
383 | } |
---|
384 | |
---|
385 | sigma *= sigmafactor; |
---|
386 | |
---|
387 | // nucl. size correction for particles other than e+/e- only at present !!!! |
---|
388 | if((particle->GetParticleName() != "e-") && |
---|
389 | (particle->GetParticleName() != "e+") ) |
---|
390 | sigma /= corrnuclsize; |
---|
391 | // G4cout << "e= " << KineticEnergy << " sigma= " << sigma << G4endl; |
---|
392 | |
---|
393 | return sigma; |
---|
394 | } |
---|
395 | |
---|
396 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
397 | |
---|
398 | G4double G4MscModel71::GeomPathLength( |
---|
399 | G4PhysicsTable* theLambdaTable, |
---|
400 | const G4MaterialCutsCouple* couple, |
---|
401 | const G4ParticleDefinition* theParticle, |
---|
402 | G4double& T0, |
---|
403 | G4double lambda, |
---|
404 | G4double range, |
---|
405 | G4double truePathLength) |
---|
406 | { |
---|
407 | // do the true -> geom transformation |
---|
408 | const G4double ztmax = 101./103. ; |
---|
409 | if (theParticle != particle ) { |
---|
410 | particle = theParticle; |
---|
411 | mass = particle->GetPDGMass(); |
---|
412 | charge = particle->GetPDGCharge()/eplus; |
---|
413 | } |
---|
414 | currentKinEnergy = T0; |
---|
415 | currentRange = range ; |
---|
416 | currentRadLength = couple->GetMaterial()->GetRadlen(); |
---|
417 | |
---|
418 | lambda0 = lambda; |
---|
419 | par1 = -1. ; |
---|
420 | par2 = par3 = 0. ; |
---|
421 | tPathLength = truePathLength; |
---|
422 | |
---|
423 | // this correction needed to run MSC with eIoni and eBrem inactivated |
---|
424 | // and makes no harm for a normal run |
---|
425 | if(tPathLength > range) |
---|
426 | tPathLength = range ; |
---|
427 | |
---|
428 | G4double tau = tPathLength/lambda0 ; |
---|
429 | |
---|
430 | if (tau <= tausmall) return tPathLength; |
---|
431 | |
---|
432 | G4double zmean = tPathLength; |
---|
433 | if (tPathLength < range*dtrl) { |
---|
434 | zmean = lambda0*(1.-exp(-tau)); |
---|
435 | if(tau < taulim) zmean = tPathLength*(1.-0.5*tPathLength/lambda0) ; |
---|
436 | } else if(T0 < mass) { |
---|
437 | par1 = 1./range ; |
---|
438 | par2 = 1./(par1*lambda0) ; |
---|
439 | par3 = 1.+par2 ; |
---|
440 | zmean = (1.-exp(par3*log(1.-tPathLength/range)))/(par1*par3) ; |
---|
441 | } else { |
---|
442 | G4LossTableManager* theManager = G4LossTableManager::Instance(); |
---|
443 | G4double T1 = theManager->GetEnergy(particle,range-tPathLength,couple); |
---|
444 | G4double lambda1 ; |
---|
445 | if (theLambdaTable) { |
---|
446 | G4bool bb; |
---|
447 | lambda1 = ((*theLambdaTable)[couple->GetIndex()])->GetValue(T1,bb); |
---|
448 | } else { |
---|
449 | lambda1 = CrossSection(couple,particle,T1,0.0,1.0); |
---|
450 | } |
---|
451 | lambda1 = 1.0/lambda1; |
---|
452 | par1 = (lambda0-lambda1)/(lambda0*tPathLength) ; |
---|
453 | par2 = 1./(par1*lambda0) ; |
---|
454 | par3 = 1.+par2 ; |
---|
455 | zmean = (1.-exp(par3*log(lambda1/lambda0)))/(par1*par3) ; |
---|
456 | } |
---|
457 | |
---|
458 | // sample z |
---|
459 | G4double zPathLength = zmean ; |
---|
460 | G4double zt = zmean/tPathLength ; |
---|
461 | if (tPathLength >= stepmin && samplez && zt > 0.5 && zt < ztmax) |
---|
462 | { |
---|
463 | G4double cz = 0.5*(3.*zt-1.)/(1.-zt) ; |
---|
464 | G4double cz1 = 1.+cz ; |
---|
465 | G4double u0 = cz/cz1 ; |
---|
466 | G4double u,grej ; |
---|
467 | do { |
---|
468 | u = exp(log(G4UniformRand())/cz1) ; |
---|
469 | grej = exp(cz*log(u/u0))*(1.-u)/(1.-u0) ; |
---|
470 | } while (grej < G4UniformRand()) ; |
---|
471 | zPathLength = tPathLength*u ; |
---|
472 | } |
---|
473 | |
---|
474 | return zPathLength ; |
---|
475 | } |
---|
476 | |
---|
477 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
478 | |
---|
479 | G4double G4MscModel71::TrueStepLength(G4double geomStepLength) |
---|
480 | { |
---|
481 | G4double trueLength = geomStepLength; |
---|
482 | trueLength = geomStepLength; |
---|
483 | if(geomStepLength > lambda0*tausmall) |
---|
484 | { |
---|
485 | if(par1 < 0.) |
---|
486 | trueLength = -lambda0*log(1.-geomStepLength/lambda0) ; |
---|
487 | else |
---|
488 | { |
---|
489 | if(par1*par3*geomStepLength < 1.) |
---|
490 | trueLength = (1.-exp(log(1.-par1*par3*geomStepLength)/par3))/par1 ; |
---|
491 | else |
---|
492 | trueLength = currentRange ; |
---|
493 | } |
---|
494 | } |
---|
495 | |
---|
496 | if(trueLength > tPathLength) trueLength = tPathLength; |
---|
497 | if(trueLength > currentRange) trueLength = currentRange ; |
---|
498 | if(trueLength < geomStepLength) trueLength = geomStepLength; |
---|
499 | |
---|
500 | return trueLength; |
---|
501 | } |
---|
502 | |
---|
503 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
504 | |
---|
505 | void G4MscModel71::SampleSecondaries(std::vector<G4DynamicParticle*>*, |
---|
506 | const G4MaterialCutsCouple*, |
---|
507 | const G4DynamicParticle* dynParticle, |
---|
508 | G4double truestep, |
---|
509 | G4double safety) |
---|
510 | { |
---|
511 | G4double kineticEnergy = dynParticle->GetKineticEnergy(); |
---|
512 | if(kineticEnergy <= 0.0) return; |
---|
513 | |
---|
514 | G4double cth = SampleCosineTheta(truestep,kineticEnergy); |
---|
515 | G4double sth = sqrt((1.0 - cth)*(1.0 + cth)); |
---|
516 | G4double phi = twopi*G4UniformRand(); |
---|
517 | G4double dirx = sth*cos(phi); |
---|
518 | G4double diry = sth*sin(phi); |
---|
519 | |
---|
520 | G4ThreeVector oldDirection = dynParticle->GetMomentumDirection(); |
---|
521 | G4ThreeVector newDirection(dirx,diry,cth); |
---|
522 | newDirection.rotateUz(oldDirection); |
---|
523 | fParticleChange->ProposeMomentumDirection(newDirection); |
---|
524 | |
---|
525 | /* |
---|
526 | const G4ParticleDefinition* pd = dynParticle->GetDefinition(); |
---|
527 | G4cout << "G4MscModel71: Sample secondary; E(MeV)= " << kineticEnergy/MeV |
---|
528 | << " MeV; step(mm)= " << truestep/mm |
---|
529 | << ", safety(mm)= " << safety/mm << " " << pd->GetParticleName() |
---|
530 | << G4endl; |
---|
531 | */ |
---|
532 | |
---|
533 | if (latDisplasment && safety > 0.0) { |
---|
534 | |
---|
535 | G4double r = SampleDisplacement(); |
---|
536 | if (r > safety) r = safety; |
---|
537 | |
---|
538 | // sample direction of lateral displacement |
---|
539 | G4double phi = twopi*G4UniformRand(); |
---|
540 | G4double dirx = std::cos(phi); |
---|
541 | G4double diry = std::sin(phi); |
---|
542 | |
---|
543 | G4ThreeVector newPosition(dirx,diry,0.0); |
---|
544 | newPosition.rotateUz(oldDirection); |
---|
545 | |
---|
546 | // compute new endpoint of the Step |
---|
547 | newPosition *= r; |
---|
548 | newPosition += *(fParticleChange->GetProposedPosition()); |
---|
549 | |
---|
550 | navigator->LocateGlobalPointWithinVolume(newPosition); |
---|
551 | |
---|
552 | fParticleChange->ProposePosition(newPosition); |
---|
553 | } |
---|
554 | } |
---|
555 | |
---|
556 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
557 | |
---|
558 | G4double G4MscModel71::SampleCosineTheta(G4double trueStepLength, G4double KineticEnergy) |
---|
559 | { |
---|
560 | G4double cth = 1. ; |
---|
561 | G4double tau = trueStepLength/lambda0 ; |
---|
562 | |
---|
563 | if(trueStepLength >= currentRange*dtrl) |
---|
564 | if(par1*trueStepLength < 1.) |
---|
565 | tau = -par2*log(1.-par1*trueStepLength) ; |
---|
566 | else |
---|
567 | tau = taubig ; |
---|
568 | |
---|
569 | currentTau = tau ; |
---|
570 | |
---|
571 | if(trueStepLength < stepmin) |
---|
572 | cth = exp(-tau) ; |
---|
573 | else |
---|
574 | { |
---|
575 | if (tau >= taubig) cth = -1.+2.*G4UniformRand(); |
---|
576 | else if (tau >= tausmall) |
---|
577 | { |
---|
578 | G4double a ; |
---|
579 | |
---|
580 | // for all particles take the width of the central part |
---|
581 | // from a parametrization similar to the Highland formula |
---|
582 | // ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10) |
---|
583 | // here : theta0 = 13.6*MeV*Q*(t/X0)**0.555/(beta*cp) |
---|
584 | const G4double c_highland = 13.6*MeV, corr_highland=0.555 ; |
---|
585 | G4double Q = std::abs(charge) ; |
---|
586 | G4double xx0 = trueStepLength/currentRadLength; |
---|
587 | G4double betacp = sqrt(currentKinEnergy*(currentKinEnergy+2.*mass)* |
---|
588 | KineticEnergy*(KineticEnergy+2.*mass)/ |
---|
589 | ((currentKinEnergy+mass)*(KineticEnergy+mass))) ; |
---|
590 | G4double theta0 = c_highland*Q*exp(corr_highland*log(xx0))/betacp ; |
---|
591 | |
---|
592 | if(theta0 > taulim) a = 0.5/(1.-cos(theta0)) ; |
---|
593 | else a = 1.0/(theta0*theta0) ; |
---|
594 | |
---|
595 | G4double xmeanth = exp(-tau); |
---|
596 | G4double xmeanth1 = 1.-xmeanth ; |
---|
597 | if(currentTau < taulim) xmeanth1 = tau ; |
---|
598 | |
---|
599 | const G4double x1fac1 = exp(-xsi) ; |
---|
600 | const G4double x1fac2 = (1.-(1.+xsi)*x1fac1)/(1.-x1fac1) ; |
---|
601 | const G4double x1fac3 = 1.3 ; |
---|
602 | |
---|
603 | G4double ea,eaa,xmean1 ; |
---|
604 | G4double c = 2.,b1 = 2., bx = 2., |
---|
605 | eb1 = b1, ebx = b1, xmean2 = 0. ; |
---|
606 | G4double prob = 1., qprob ; |
---|
607 | G4double x0 = 1.-xsi/a; |
---|
608 | G4double oneminusx0=xsi/a ; |
---|
609 | G4double oneplusx0=2.+xsi/a ; |
---|
610 | |
---|
611 | G4double f1x0=1., f2x0=1. ; |
---|
612 | const G4double tau0 = 0.10 ; |
---|
613 | if(tau > tau0) |
---|
614 | { |
---|
615 | // 1 model function |
---|
616 | a = 1./xmeanth1 ; |
---|
617 | ea = exp(-2.*a) ; |
---|
618 | eaa= 1.-ea ; |
---|
619 | xmean1 = 1.-1./a+2.*ea/eaa ; |
---|
620 | prob = 1. ; |
---|
621 | qprob = 1. ; |
---|
622 | } |
---|
623 | else if (x0 <= -1.) |
---|
624 | { |
---|
625 | // 2 model fuctions only |
---|
626 | // in order to have xmean1 > xmeanth -> qprob < 1 |
---|
627 | x0 = -1.; |
---|
628 | |
---|
629 | if( a < 1./xmeanth1) |
---|
630 | a = 1./xmeanth1 ; |
---|
631 | |
---|
632 | oneminusx0 = 1.-x0 ; |
---|
633 | oneplusx0 = 1.+x0 ; |
---|
634 | ea = exp(-a*oneminusx0); |
---|
635 | eaa = 1.-ea ; |
---|
636 | xmean1 = 1.-1./a+oneminusx0*ea/eaa ; |
---|
637 | qprob = xmeanth/xmean1 ; |
---|
638 | |
---|
639 | } |
---|
640 | else |
---|
641 | { |
---|
642 | // 3 model fuctions |
---|
643 | // in order to have xmean1 > xmeanth |
---|
644 | if((1.-x1fac2/a) < xmeanth) |
---|
645 | { |
---|
646 | a = x1fac3*x1fac2/xmeanth1 ; |
---|
647 | x0 = 1.-xsi/a ; |
---|
648 | oneminusx0=xsi/a ; |
---|
649 | oneplusx0=2.-xsi/a ; |
---|
650 | } |
---|
651 | |
---|
652 | ea = x1fac1 ; |
---|
653 | eaa = 1.-ea ; |
---|
654 | xmean1 = 1.-x1fac2/a ; |
---|
655 | |
---|
656 | const G4double fctail = factail*1.0 ; |
---|
657 | c = 2.+fctail*tau ; |
---|
658 | G4double c1 = c-1. ; |
---|
659 | G4double c2 = c-2. ; |
---|
660 | if(c2 == 0.) c2 = fctail*tausmall ; |
---|
661 | |
---|
662 | b = 1.+(c-xsi)/a ; |
---|
663 | |
---|
664 | b1 = b+1. ; |
---|
665 | bx = c/a ; |
---|
666 | eb1=exp((c1)*log(b1)) ; |
---|
667 | ebx=exp((c1)*log(bx)) ; |
---|
668 | xmean2 = (x0*eb1+ebx-(eb1*bx-b1*ebx)/c2)/(eb1-ebx) ; |
---|
669 | |
---|
670 | f1x0 = a*ea/eaa ; |
---|
671 | f2x0 = c1*eb1*ebx/(eb1-ebx)/ |
---|
672 | exp(c*log(bx)) ; |
---|
673 | // from continuity at x=x0 |
---|
674 | prob = f2x0/(f1x0+f2x0) ; |
---|
675 | // from xmean = xmeanth |
---|
676 | qprob = (f1x0+f2x0)*xmeanth/(f2x0*xmean1+f1x0*xmean2) ; |
---|
677 | |
---|
678 | } |
---|
679 | |
---|
680 | // sampling of costheta |
---|
681 | if (G4UniformRand() < qprob) |
---|
682 | { |
---|
683 | if (G4UniformRand() < prob) |
---|
684 | cth = 1.+log(ea+G4UniformRand()*eaa)/a ; |
---|
685 | else |
---|
686 | cth = b-b1*bx/exp(log(ebx-G4UniformRand()*(ebx-eb1))/(c-1.)) ; |
---|
687 | } |
---|
688 | else |
---|
689 | { |
---|
690 | cth = -1.+2.*G4UniformRand(); |
---|
691 | } |
---|
692 | } |
---|
693 | } |
---|
694 | |
---|
695 | return cth ; |
---|
696 | } |
---|
697 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
698 | |
---|
699 | G4double G4MscModel71::SampleDisplacement() |
---|
700 | { |
---|
701 | const G4double kappa = 2.5; |
---|
702 | const G4double kappapl1 = kappa+1.; |
---|
703 | const G4double kappami1 = kappa-1.; |
---|
704 | G4double rmean = 0.0; |
---|
705 | if (currentTau >= tausmall) { |
---|
706 | if (currentTau < taulim) { |
---|
707 | rmean = kappa*currentTau*currentTau*currentTau*(1.-kappapl1*currentTau*0.25)/6. ; |
---|
708 | |
---|
709 | } else { |
---|
710 | G4double etau = 0.0; |
---|
711 | if (currentTau<taubig) etau = exp(-currentTau); |
---|
712 | rmean = -kappa*currentTau; |
---|
713 | rmean = -exp(rmean)/(kappa*kappami1); |
---|
714 | rmean += currentTau-kappapl1/kappa+kappa*etau/kappami1; |
---|
715 | } |
---|
716 | if (rmean>0.) rmean = 2.*lambda0*sqrt(rmean/3.0); |
---|
717 | else rmean = 0.; |
---|
718 | } |
---|
719 | return rmean; |
---|
720 | } |
---|
721 | |
---|
722 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
723 | |
---|
724 | |
---|
725 | |
---|
726 | |
---|