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: G4RToEConvForElectron.cc,v 1.7 2009/09/11 15:21:39 kurasige Exp $ |
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28 | // GEANT4 tag $Name: geant4-09-03-cand-01 $ |
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29 | // |
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30 | // |
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31 | // -------------------------------------------------------------- |
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32 | // GEANT 4 class implementation file/ History: |
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33 | // 5 Oct. 2002, H.Kuirashige : Structure created based on object model |
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34 | // -------------------------------------------------------------- |
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35 | |
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36 | #include "G4RToEConvForElectron.hh" |
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37 | #include "G4ParticleDefinition.hh" |
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38 | #include "G4ParticleTable.hh" |
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39 | #include "G4Material.hh" |
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40 | #include "G4PhysicsLogVector.hh" |
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41 | |
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42 | #include "G4ios.hh" |
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43 | |
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44 | G4RToEConvForElectron::G4RToEConvForElectron() : G4VRangeToEnergyConverter() |
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45 | { |
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46 | theParticle = G4ParticleTable::GetParticleTable()->FindParticle("e-"); |
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47 | if (theParticle ==0) { |
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48 | #ifdef G4VERBOSE |
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49 | if (GetVerboseLevel()>0) { |
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50 | G4cout << " G4RToEConvForElectron::G4RToEConvForElectron() "; |
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51 | G4cout << " Electron is not defined !!" << G4endl; |
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52 | } |
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53 | #endif |
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54 | } |
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55 | } |
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56 | |
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57 | G4RToEConvForElectron::~G4RToEConvForElectron() |
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58 | { |
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59 | } |
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60 | |
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61 | |
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62 | // ********************************************************************** |
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63 | // ************************* ComputeLoss ******************************** |
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64 | // ********************************************************************** |
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65 | G4double G4RToEConvForElectron::ComputeLoss(G4double AtomicNumber, |
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66 | G4double KineticEnergy) const |
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67 | { |
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68 | static G4double Z; |
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69 | static G4double taul, ionpot, ionpotlog; |
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70 | const G4double cbr1=0.02, cbr2=-5.7e-5, cbr3=1., cbr4=0.072; |
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71 | const G4double Tlow=10.*keV, Thigh=1.*GeV; |
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72 | static G4double bremfactor= 0.1 ; |
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73 | |
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74 | static G4double Mass= theParticle->GetPDGMass(); |
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75 | |
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76 | // calculate dE/dx for electrons |
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77 | if( std::fabs(AtomicNumber-Z)>0.1 ) { |
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78 | Z = AtomicNumber; |
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79 | taul = Tlow/Mass; |
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80 | ionpot = 1.6e-5*MeV*std::exp(0.9*std::log(Z))/Mass; |
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81 | ionpotlog = std::log(ionpot); |
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82 | } |
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83 | |
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84 | |
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85 | G4double tau = KineticEnergy/Mass; |
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86 | G4double dEdx; |
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87 | |
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88 | if(tau<taul) { |
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89 | G4double t1 = taul+1.; |
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90 | G4double t2 = taul+2.; |
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91 | G4double tsq = taul*taul; |
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92 | G4double beta2 = taul*t2/(t1*t1); |
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93 | G4double f = 1.-beta2+std::log(tsq/2.) |
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94 | +(0.5+0.25*tsq+(1.+2.*taul)*std::log(0.5))/(t1*t1); |
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95 | dEdx = (std::log(2.*taul+4.)-2.*ionpotlog+f)/beta2; |
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96 | dEdx = twopi_mc2_rcl2*Z*dEdx; |
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97 | G4double clow = dEdx*std::sqrt(taul); |
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98 | dEdx = clow/std::sqrt(KineticEnergy/Mass); |
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99 | |
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100 | } else { |
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101 | G4double t1 = tau+1.; |
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102 | G4double t2 = tau+2.; |
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103 | G4double tsq = tau*tau; |
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104 | G4double beta2 = tau*t2/(t1*t1); |
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105 | G4double f = 1.-beta2+std::log(tsq/2.) |
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106 | +(0.5+0.25*tsq+(1.+2.*tau)*std::log(0.5))/(t1*t1); |
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107 | dEdx = (std::log(2.*tau+4.)-2.*ionpotlog+f)/beta2; |
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108 | dEdx = twopi_mc2_rcl2*Z*dEdx; |
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109 | |
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110 | // loss from bremsstrahlung follows |
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111 | G4double cbrem = (cbr1+cbr2*Z) |
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112 | *(cbr3+cbr4*std::log(KineticEnergy/Thigh)); |
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113 | cbrem = Z*(Z+1.)*cbrem*tau/beta2; |
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114 | |
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115 | cbrem *= bremfactor ; |
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116 | |
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117 | dEdx += twopi_mc2_rcl2*cbrem; |
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118 | } |
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119 | |
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120 | return dEdx; |
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121 | } |
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