[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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[1196] | 27 | // $Id: G4RToEConvForPositron.cc,v 1.7 2009/09/11 15:21:39 kurasige Exp $ |
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[1337] | 28 | // GEANT4 tag $Name: geant4-09-04-beta-01 $ |
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[819] | 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 "G4RToEConvForPositron.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 | G4RToEConvForPositron::G4RToEConvForPositron() : 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 << " G4RToEConvForPositron::G4RToEConvForPositron() "; |
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| 51 | G4cout << " Positron 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 | G4RToEConvForPositron::~G4RToEConvForPositron() |
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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 | |
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| 64 | // ********************************************************************** |
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| 65 | // ************************* ComputeLoss ******************************** |
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| 66 | // ********************************************************************** |
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| 67 | G4double G4RToEConvForPositron::ComputeLoss(G4double AtomicNumber, |
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| 68 | G4double KineticEnergy) const |
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| 69 | { |
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| 70 | static G4double Z; |
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| 71 | static G4double taul, ionpot, ionpotlog; |
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| 72 | const G4double cbr1=0.02, cbr2=-5.7e-5, cbr3=1., cbr4=0.072; |
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| 73 | const G4double Tlow=10.*keV, Thigh=1.*GeV; |
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| 74 | static G4double bremfactor = 0.1 ; |
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| 75 | |
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| 76 | G4double Mass = theParticle->GetPDGMass(); |
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| 77 | // calculate dE/dx for electrons |
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[1055] | 78 | if( std::fabs(AtomicNumber-Z)>0.1 ) { |
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[819] | 79 | Z = AtomicNumber; |
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| 80 | taul = Tlow/Mass; |
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| 81 | ionpot = 1.6e-5*MeV*std::exp(0.9*std::log(Z))/Mass; |
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| 82 | ionpotlog = std::log(ionpot); |
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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 | { |
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| 90 | G4double t1 = taul+1.; |
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| 91 | G4double t2 = taul+2.; |
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| 92 | G4double tsq = taul*taul; |
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| 93 | G4double beta2 = taul*t2/(t1*t1); |
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| 94 | G4double f = 2.*std::log(taul) |
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| 95 | -(6.*taul+1.5*tsq-taul*(1.-tsq/3.)/t2-tsq*(0.5-tsq/12.)/ |
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| 96 | (t2*t2))/(t1*t1); |
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| 97 | dEdx = (std::log(2.*taul+4.)-2.*ionpotlog+f)/beta2; |
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| 98 | dEdx = twopi_mc2_rcl2*Z*dEdx; |
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| 99 | G4double clow = dEdx*std::sqrt(taul); |
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| 100 | dEdx = clow/std::sqrt(KineticEnergy/Mass); |
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| 101 | |
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| 102 | } else { |
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| 103 | G4double t1 = tau+1.; |
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| 104 | G4double t2 = tau+2.; |
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| 105 | G4double tsq = tau*tau; |
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| 106 | G4double beta2 = tau*t2/(t1*t1); |
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| 107 | G4double f = 2.*std::log(tau) |
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| 108 | - (6.*tau+1.5*tsq-tau*(1.-tsq/3.)/t2-tsq*(0.5-tsq/12.)/ |
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| 109 | (t2*t2))/(t1*t1); |
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| 110 | dEdx = (std::log(2.*tau+4.)-2.*ionpotlog+f)/beta2; |
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| 111 | dEdx = twopi_mc2_rcl2*Z*dEdx; |
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| 112 | |
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| 113 | // loss from bremsstrahlung follows |
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| 114 | G4double cbrem = (cbr1+cbr2*Z) |
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| 115 | *(cbr3+cbr4*std::log(KineticEnergy/Thigh)); |
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| 116 | cbrem = Z*(Z+1.)*cbrem*tau/beta2; |
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| 117 | cbrem *= bremfactor ; |
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| 118 | dEdx += twopi_mc2_rcl2*cbrem; |
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| 119 | } |
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| 120 | return dEdx; |
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| 121 | } |
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| 122 | |
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| 123 | |
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