[819] | 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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