1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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7 | // * conditions of the Geant4 Software License, included in the file * |
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8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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9 | // * include a list of copyright holders. * |
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10 | // * * |
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11 | // * Neither the authors of this software system, nor their employing * |
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12 | // * institutes,nor the agencies providing financial support for this * |
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13 | // * work make any representation or warranty, express or implied, * |
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14 | // * regarding this software system or assume any liability for its * |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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16 | // * for the full disclaimer and the limitation of liability. * |
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17 | // * * |
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18 | // * This code implementation is the result of the scientific and * |
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19 | // * technical work of the GEANT4 collaboration. * |
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20 | // * By using, copying, modifying or distributing the software (or * |
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21 | // * any work based on the software) you agree to acknowledge its * |
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22 | // * use in resulting scientific publications, and indicate your * |
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23 | // * acceptance of all terms of the Geant4 Software license. * |
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24 | // ******************************************************************** |
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25 | // |
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26 | // |
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27 | // $Id: G4CrossSectionExcitationEmfietzoglouPartial.cc,v 1.2 2007/12/10 16:31:26 gunter Exp $ |
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28 | // GEANT4 tag $Name: $ |
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29 | // |
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30 | // Contact Author: Maria Grazia Pia (Maria.Grazia.Pia@cern.ch) |
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31 | // |
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32 | // Reference: TNS Geant4-DNA paper |
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33 | // Reference for implementation model: NIM. 155, pp. 145-156, 1978 |
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34 | |
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35 | // History: |
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36 | // ----------- |
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37 | // Date Name Modification |
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38 | // 28 Apr 2007 M.G. Pia Created in compliance with design described in TNS paper |
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39 | // |
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40 | // ------------------------------------------------------------------- |
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41 | |
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42 | // Class description: |
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43 | // Geant4-DNA Cross total cross section for electron elastic scattering in water |
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44 | // Reference: TNS Geant4-DNA paper |
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45 | // S. Chauvie et al., Geant4 physics processes for microdosimetry simulation: |
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46 | // design foundation and implementation of the first set of models, |
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47 | // IEEE Trans. Nucl. Sci., vol. 54, no. 6, Dec. 2007. |
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48 | // Further documentation available from http://www.ge.infn.it/geant4/dna |
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49 | |
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50 | // ------------------------------------------------------------------- |
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51 | |
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52 | |
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53 | #include "G4CrossSectionExcitationEmfietzoglouPartial.hh" |
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54 | #include "G4Track.hh" |
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55 | #include "G4DynamicParticle.hh" |
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56 | #include "G4ParticleDefinition.hh" |
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57 | #include "G4Electron.hh" |
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58 | |
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59 | #include "Randomize.hh" |
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60 | |
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61 | #include <deque> |
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62 | |
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63 | G4CrossSectionExcitationEmfietzoglouPartial::G4CrossSectionExcitationEmfietzoglouPartial() |
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64 | { |
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65 | |
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66 | nLevels = waterExcitation.NumberOfLevels(); |
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67 | //G4cout << "Water excitation energy: number of levels = " << nLevels << G4endl; |
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68 | } |
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69 | |
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70 | |
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71 | G4CrossSectionExcitationEmfietzoglouPartial::~G4CrossSectionExcitationEmfietzoglouPartial() |
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72 | { } |
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73 | |
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74 | G4double G4CrossSectionExcitationEmfietzoglouPartial::CrossSection(G4double t, G4int level) |
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75 | { |
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76 | // Aj T |
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77 | // Sigma(T) = ------------- (Bj / T) ln(Cj ---) [1 - Bj / T]^Pj |
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78 | // 2 pi alpha0 R |
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79 | // |
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80 | // Sigma is the macroscopic cross section = N sigma, where N = number of target particles per unit volume |
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81 | // and sigma is the microscopic cross section |
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82 | // T is the incoming electron kinetic energy |
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83 | // alpha0 is the Bohr Radius (Bohr_radius) |
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84 | // Aj, Bj, Cj & Pj are parameters that can be found in Emfietzoglou's papers |
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85 | // |
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86 | // |
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87 | // From Phys. Med. Biol. 48 (2003) 2355-2371, D.Emfietzoglou, |
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88 | // Monte Carlo Simulation of the energy loss of low energy electrons in liquid Water |
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89 | |
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90 | // Scaling for macroscopic cross section: number of water moleculs per unit volume |
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91 | // (capra) const G4double sigma0 = (10. / 3.343e22) * cm2; |
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92 | const G4double density = 3.34192e+19 * mm3; |
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93 | |
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94 | const G4double aj[]={0.0205, 0.0209, 0.0130, 0.0026, 0.0025}; |
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95 | const G4double cj[]={4.9801, 3.3850, 2.8095, 1.9242, 3.4624}; |
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96 | const G4double pj[]={0.4757, 0.3483, 0.4443, 0.3429, 0.4379}; |
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97 | const G4double r = 13.6 * eV; |
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98 | |
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99 | G4double sigma = 0.; |
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100 | |
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101 | G4double exc = waterExcitation.ExcitationEnergy(level); |
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102 | // G4cout << "Water excitation energy " << exc/keV << " level = " << level << G4endl; |
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103 | |
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104 | if (t >= exc) |
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105 | { |
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106 | G4double excitationSigma = ( aj[level] / (2.*pi*Bohr_radius)) |
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107 | * (exc / t) |
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108 | * std::log(cj[level]*(t/r)) |
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109 | * std::pow((1.- (exc/t)), pj[level]); |
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110 | sigma = excitationSigma / density; |
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111 | } |
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112 | return sigma; |
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113 | } |
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114 | |
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115 | G4int G4CrossSectionExcitationEmfietzoglouPartial::RandomSelect(G4double k) |
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116 | { |
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117 | G4int i = nLevels; |
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118 | G4double value = 0.; |
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119 | std::deque<double> values; |
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120 | |
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121 | // ---- MGP ---- The following algorithm is wrong: it works is the cross section |
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122 | // is a monotone increasing function. |
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123 | // The algorithm should be corrected by building the cumulative function |
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124 | // of the cross section and comparing a random number in the range 0-1 against |
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125 | // the cumulative value at each bin |
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126 | |
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127 | while (i > 0) |
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128 | { |
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129 | i--; |
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130 | G4double partial = CrossSection(k,i); |
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131 | values.push_front(partial); |
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132 | value += partial; |
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133 | } |
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134 | |
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135 | value *= G4UniformRand(); |
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136 | |
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137 | i = nLevels; |
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138 | |
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139 | while (i > 0) |
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140 | { |
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141 | i--; |
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142 | if (values[i] > value) return i; |
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143 | value -= values[i]; |
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144 | } |
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145 | |
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146 | return 0; |
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147 | } |
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148 | |
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149 | G4double G4CrossSectionExcitationEmfietzoglouPartial::Sum(G4double k) |
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150 | { |
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151 | G4double totalCrossSection = 0.; |
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152 | |
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153 | for (G4int i=0; i<nLevels; i++) |
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154 | { |
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155 | totalCrossSection += CrossSection(k,i); |
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156 | } |
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157 | return totalCrossSection; |
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158 | } |
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