[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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[961] | 26 | // $Id: G4ionEffectiveCharge.cc,v 1.24 2008/12/18 13:01:46 gunter Exp $ |
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[1007] | 27 | // GEANT4 tag $Name: geant4-09-02 $ |
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[819] | 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: G4ionEffectiveCharge |
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| 35 | // |
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| 36 | // Author: Vladimir Ivanchenko |
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| 37 | // |
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| 38 | // Creation date: 07.05.2002 |
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| 39 | // |
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| 40 | // Modifications: |
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| 41 | // 12.09.2004 Set low energy limit to 1 keV (V.Ivanchenko) |
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| 42 | // 25.01.2005 Add protection - min Charge 0.1 eplus (V.Ivanchenko) |
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| 43 | // 28.04.2006 Set upper energy limit to 50 MeV (V.Ivanchenko) |
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| 44 | // 23.05.2006 Set upper energy limit to Z*10 MeV (V.Ivanchenko) |
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| 45 | // 15.08.2006 Add protection for not defined material (V.Ivanchenko) |
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| 46 | // 27-09-2007 Use Fermi energy from material, optimazed formulas (V.Ivanchenko) |
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| 47 | // |
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| 48 | |
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| 49 | // ------------------------------------------------------------------- |
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| 50 | // |
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| 51 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 52 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 53 | |
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| 54 | #include "G4ionEffectiveCharge.hh" |
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| 55 | #include "G4UnitsTable.hh" |
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| 56 | #include "G4Material.hh" |
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[961] | 57 | #include "G4NistManager.hh" |
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[819] | 58 | |
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| 59 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 60 | |
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| 61 | G4ionEffectiveCharge::G4ionEffectiveCharge() |
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| 62 | { |
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| 63 | chargeCorrection = 1.0; |
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[961] | 64 | energyHighLimit = 20.0*MeV; |
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[819] | 65 | energyLowLimit = 1.0*keV; |
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| 66 | energyBohr = 25.*keV; |
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| 67 | massFactor = amu_c2/(proton_mass_c2*keV); |
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[961] | 68 | minCharge = 1.0; |
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| 69 | lastPart = 0; |
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| 70 | lastMat = 0; |
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| 71 | lastKinEnergy = 0.0; |
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| 72 | effCharge = eplus; |
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| 73 | nist = G4NistManager::Instance(); |
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[819] | 74 | } |
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| 75 | |
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| 76 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 77 | |
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| 78 | G4ionEffectiveCharge::~G4ionEffectiveCharge() |
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| 79 | {} |
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| 80 | |
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| 81 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 82 | |
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| 83 | G4double G4ionEffectiveCharge::EffectiveCharge(const G4ParticleDefinition* p, |
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| 84 | const G4Material* material, |
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[961] | 85 | G4double kineticEnergy) |
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[819] | 86 | { |
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[961] | 87 | if(p == lastPart && material == lastMat && kineticEnergy == lastKinEnergy) |
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| 88 | return effCharge; |
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| 89 | |
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| 90 | lastPart = p; |
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| 91 | lastMat = material; |
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| 92 | lastKinEnergy = kineticEnergy; |
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| 93 | |
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[819] | 94 | G4double mass = p->GetPDGMass(); |
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| 95 | G4double charge = p->GetPDGCharge(); |
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| 96 | G4double Zi = charge/eplus; |
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| 97 | |
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| 98 | chargeCorrection = 1.0; |
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[961] | 99 | effCharge = charge; |
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[819] | 100 | |
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| 101 | // The aproximation of ion effective charge from: |
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| 102 | // J.F.Ziegler, J.P. Biersack, U. Littmark |
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| 103 | // The Stopping and Range of Ions in Matter, |
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| 104 | // Vol.1, Pergamon Press, 1985 |
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| 105 | // Fast ions or hadrons |
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| 106 | G4double reducedEnergy = kineticEnergy * proton_mass_c2/mass ; |
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| 107 | if( reducedEnergy > Zi*energyHighLimit || Zi < 1.5 || !material) return charge; |
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| 108 | |
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| 109 | G4double z = material->GetIonisation()->GetZeffective(); |
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[961] | 110 | // reducedEnergy = std::max(reducedEnergy,energyLowLimit); |
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[819] | 111 | |
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| 112 | // Helium ion case |
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| 113 | if( Zi < 2.5 ) { |
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| 114 | |
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[961] | 115 | static G4double c[6] = {0.2865, 0.1266, -0.001429, |
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| 116 | 0.02402,-0.01135, 0.001475} ; |
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| 117 | |
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[819] | 118 | G4double Q = std::max(0.0,std::log(reducedEnergy*massFactor)); |
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| 119 | G4double x = c[0]; |
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| 120 | G4double y = 1.0; |
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| 121 | for (G4int i=1; i<6; i++) { |
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| 122 | y *= Q; |
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| 123 | x += y * c[i] ; |
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| 124 | } |
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| 125 | G4double ex; |
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| 126 | if(x < 0.2) ex = x * (1 - 0.5*x); |
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| 127 | else ex = 1. - std::exp(-x); |
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| 128 | |
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| 129 | G4double tq = 7.6 - Q; |
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| 130 | G4double tq2= tq*tq; |
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| 131 | G4double tt = ( 0.007 + 0.00005 * z ); |
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| 132 | if(tq2 < 0.2) tt *= (1.0 - tq2 + 0.5*tq2*tq2); |
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| 133 | else tt *= std::exp(-tq2); |
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| 134 | |
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[961] | 135 | effCharge = charge*(1.0 + tt) * std::sqrt(ex); |
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| 136 | |
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[819] | 137 | // Heavy ion case |
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| 138 | } else { |
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| 139 | |
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[961] | 140 | G4double y; |
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| 141 | // = nist->GetZ13(z); |
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| 142 | //G4double z23 = y*y; |
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| 143 | G4double zi13 = nist->GetZ13(Zi); |
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[819] | 144 | G4double zi23 = zi13*zi13; |
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[961] | 145 | // G4double e = std::max(reducedEnergy,energyBohr/z23); |
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| 146 | //G4double e = reducedEnergy; |
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[819] | 147 | |
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| 148 | // v1 is ion velocity in vF unit |
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| 149 | G4double eF = material->GetIonisation()->GetFermiEnergy(); |
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[961] | 150 | G4double v1sq = reducedEnergy/eF; |
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[819] | 151 | G4double vFsq = eF/energyBohr; |
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[961] | 152 | G4double vF = std::sqrt(eF/energyBohr); |
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[819] | 153 | |
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| 154 | // Faster than Fermi velocity |
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| 155 | if ( v1sq > 1.0 ) { |
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| 156 | y = vF * std::sqrt(v1sq) * ( 1.0 + 0.2/v1sq ) / zi23 ; |
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| 157 | |
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| 158 | // Slower than Fermi velocity |
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| 159 | } else { |
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| 160 | y = 0.692308 * vF * (1.0 + 0.666666*v1sq + v1sq*v1sq/15.0) / zi23 ; |
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| 161 | } |
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| 162 | |
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[961] | 163 | G4double q; |
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[819] | 164 | G4double y3 = std::pow(y, 0.3) ; |
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[961] | 165 | // G4cout<<"y= "<<y<<" y3= "<<y3<<" v1= "<<v1<<" vF= "<<vF<<G4endl; |
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[819] | 166 | q = 1.0 - std::exp( 0.803*y3 - 1.3167*y3*y3 - 0.38157*y - 0.008983*y*y ) ; |
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[961] | 167 | |
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| 168 | //y *= 0.77; |
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| 169 | //y *= (0.75 + 0.52/Zi); |
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[819] | 170 | |
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[961] | 171 | //if( y < 0.2 ) q = y*(1.0 - 0.5*y); |
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| 172 | //else q = 1.0 - std::exp(-y); |
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[819] | 173 | |
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| 174 | G4double qmin = minCharge/Zi; |
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[961] | 175 | if(q < qmin) q = qmin; |
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| 176 | |
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| 177 | effCharge = q*charge; |
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[819] | 178 | |
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[961] | 179 | /* |
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| 180 | G4double x1 = 1.0*effCharge*(1.0 - 0.132*std::log(y))/(y*std::sqrt(z)); |
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| 181 | G4double x2 = 0.1*effCharge*effCharge*energyBohr/reducedEnergy; |
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| 182 | |
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| 183 | chargeCorrection = 1.0 + x1 - x2; |
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| 184 | |
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| 185 | G4cout << "x1= "<<x1<<" x2= "<< x2<<" corr= "<<chargeCorrection<<G4endl; |
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| 186 | */ |
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[819] | 187 | |
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| 188 | G4double tq = 7.6 - std::log(reducedEnergy/keV); |
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| 189 | G4double tq2= tq*tq; |
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| 190 | G4double sq = ( 0.18 + 0.0015 * z ) / (Zi*Zi); |
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| 191 | if(tq2 < 0.2) sq *= (1.0 - tq2 + 0.5*tq2*tq2); |
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| 192 | else sq *= std::exp(-tq2); |
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| 193 | sq += 1.0; |
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| 194 | // G4cout << "sq= " << sq << G4endl; |
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| 195 | |
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| 196 | // Screen length according to |
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| 197 | // J.F.Ziegler and J.M.Manoyan, The stopping of ions in compaunds, |
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| 198 | // Nucl. Inst. & Meth. in Phys. Res. B35 (1988) 215-228. |
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| 199 | |
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| 200 | G4double lambda = 10.0 * vF / (zi13 * (6.0 + q)); |
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[961] | 201 | if(q < 0.2) lambda *= (1.0 - 0.66666667*q - q*q/9.0); |
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[819] | 202 | else lambda *= std::pow(1.0-q, 0.666666); |
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| 203 | |
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| 204 | G4double lambda2 = lambda*lambda; |
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| 205 | |
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| 206 | G4double xx = (0.5/q - 0.5)/vFsq; |
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| 207 | if(lambda2 < 0.2) xx *= lambda2*(1.0 - 0.5*lambda2); |
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| 208 | else xx *= std::log(1.0 + lambda2); |
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| 209 | |
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| 210 | chargeCorrection = sq * (1.0 + xx); |
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[961] | 211 | |
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[819] | 212 | } |
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| 213 | // G4cout << "G4ionEffectiveCharge: charge= " << charge << " q= " << q |
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| 214 | // << " chargeCor= " << chargeCorrection |
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| 215 | // << " e(MeV)= " << kineticEnergy/MeV << G4endl; |
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[961] | 216 | return effCharge; |
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[819] | 217 | } |
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| 218 | |
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| 219 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 220 | |
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| 221 | |
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