[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 | // Implementation of formulas in analogy to NASA technical paper 3621 by |
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| 27 | // Tripathi, et al. |
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| 28 | // |
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| 29 | // 26-Dec-2006 Isotope dependence added by D. Wright |
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| 30 | // |
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| 31 | |
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| 32 | #include "G4TripathiCrossSection.hh" |
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| 33 | #include "G4ParticleTable.hh" |
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| 34 | #include "G4IonTable.hh" |
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| 35 | #include "G4HadTmpUtil.hh" |
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| 36 | |
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[1196] | 37 | G4TripathiCrossSection::G4TripathiCrossSection() |
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| 38 | { |
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| 39 | // G4cout <<"New G4TripathiCrossSection " << this << G4endl; |
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| 40 | } |
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| 41 | G4TripathiCrossSection::~G4TripathiCrossSection() |
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| 42 | {} |
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| 43 | |
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[819] | 44 | G4double G4TripathiCrossSection:: |
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| 45 | GetIsoZACrossSection(const G4DynamicParticle* aPart, G4double ZZ, G4double AA, |
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| 46 | G4double /*temperature*/) |
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| 47 | { |
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[1055] | 48 | G4double result = 0.; |
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[819] | 49 | |
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| 50 | const G4double targetAtomicNumber = AA; |
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| 51 | const G4double nTargetProtons = ZZ; |
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| 52 | |
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| 53 | const G4double kineticEnergy = aPart->GetKineticEnergy()/MeV; |
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| 54 | const G4double nProjProtons = aPart->GetDefinition()->GetPDGCharge(); |
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| 55 | const G4double projectileAtomicNumber = |
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| 56 | aPart->GetDefinition()->GetBaryonNumber(); |
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| 57 | |
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| 58 | const G4double nuleonRadius=1.1E-15; |
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| 59 | const G4double myNuleonRadius=1.36E-15; |
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| 60 | |
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| 61 | // needs target mass |
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| 62 | G4double targetMass = |
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| 63 | G4ParticleTable::GetParticleTable()->GetIonTable() |
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| 64 | ->GetIonMass(G4lrint(nTargetProtons), G4lrint(targetAtomicNumber)); |
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| 65 | G4LorentzVector pTarget(0,0,0,targetMass); |
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| 66 | G4LorentzVector pProjectile(aPart->Get4Momentum()); |
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| 67 | pTarget = pTarget+pProjectile; |
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| 68 | G4double E_cm = (pTarget.mag()-targetMass-pProjectile.m())/MeV; |
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[1055] | 69 | if(E_cm <= DBL_MIN) return result; |
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[819] | 70 | // done |
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| 71 | G4double r_rms_p = 0.6 * myNuleonRadius * |
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| 72 | std::pow(projectileAtomicNumber, 1./3.); |
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| 73 | G4double r_rms_t = 0.6 * myNuleonRadius * |
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| 74 | std::pow(targetAtomicNumber, 1./3.); |
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| 75 | |
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| 76 | // done |
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| 77 | G4double r_p = 1.29*r_rms_p/nuleonRadius ; |
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| 78 | G4double r_t = 1.29*r_rms_t/nuleonRadius; |
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| 79 | |
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| 80 | // done |
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| 81 | G4double Radius = r_p + r_t + |
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| 82 | 1.2*(std::pow(targetAtomicNumber, 1./3.) + |
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| 83 | std::pow(projectileAtomicNumber, 1./3.))/std::pow(E_cm, 1./3.); |
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| 84 | |
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| 85 | //done |
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| 86 | G4double B = 1.44*nProjProtons*nTargetProtons/Radius; |
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[1055] | 87 | if(E_cm <= B) return result; |
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[819] | 88 | // done |
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| 89 | G4double Energy = kineticEnergy/projectileAtomicNumber; |
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| 90 | |
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| 91 | // done |
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| 92 | // |
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| 93 | // Note that this correction to G4TripathiCrossSection is just to accurately |
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| 94 | // reflect Tripathi's algorithm. However, if you're using alpha |
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| 95 | // particles/protons consider using the more accurate |
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| 96 | // G4TripathiLightCrossSection, which Tripathi developed specifically for |
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| 97 | // light systems. |
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| 98 | // |
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| 99 | |
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| 100 | G4double D; |
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| 101 | if (nProjProtons==1 && projectileAtomicNumber==1) |
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| 102 | { |
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| 103 | D = 2.05; |
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| 104 | } |
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| 105 | else if (nProjProtons==2 && projectileAtomicNumber==4) |
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| 106 | { |
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| 107 | D = 2.77-(8.0E-3*targetAtomicNumber)+ |
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| 108 | (1.8E-5*targetAtomicNumber*targetAtomicNumber) |
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| 109 | - 0.8/(1+std::exp((250.-Energy)/75.)); |
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| 110 | } |
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| 111 | else |
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| 112 | { |
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| 113 | // |
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| 114 | // This is the original value used in the G4TripathiCrossSection |
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| 115 | // implementation, and was used for all projectile/target conditions. |
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| 116 | // I'm not touching this, although judging from Tripathi's paper, this is |
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| 117 | // valid for cases where the nucleon density changes little with A. |
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| 118 | // |
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| 119 | D = 1.75; |
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| 120 | } |
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| 121 | // done |
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| 122 | G4double C_E = D * (1-std::exp(-Energy/40.)) - |
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| 123 | 0.292*std::exp(-Energy/792.)*std::cos(0.229*std::pow(Energy, 0.453)); |
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| 124 | |
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| 125 | // done |
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| 126 | G4double S = std::pow(projectileAtomicNumber, 1./3.)* |
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| 127 | std::pow(targetAtomicNumber, 1./3.)/ |
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| 128 | (std::pow(projectileAtomicNumber, 1./3.) + |
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| 129 | std::pow(targetAtomicNumber, 1./3.)); |
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| 130 | |
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| 131 | // done |
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| 132 | G4double deltaE = 1.85*S + 0.16*S/std::pow(E_cm,1./3.) - C_E + |
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| 133 | 0.91*(targetAtomicNumber-2.*nTargetProtons)*nProjProtons/ |
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| 134 | (targetAtomicNumber*projectileAtomicNumber); |
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| 135 | |
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| 136 | // done |
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| 137 | result = pi * nuleonRadius*nuleonRadius * |
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| 138 | std::pow(( std::pow(targetAtomicNumber, 1./3.) + |
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| 139 | std::pow(projectileAtomicNumber, 1./3.) + deltaE),2.) * |
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| 140 | (1-B/E_cm); |
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| 141 | |
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[1055] | 142 | if(result < 0.) result = 0.; |
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[819] | 143 | return result*m2; |
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| 144 | |
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| 145 | } |
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| 146 | |
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| 147 | |
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| 148 | G4double G4TripathiCrossSection:: |
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| 149 | GetCrossSection(const G4DynamicParticle* aPart, const G4Element* anEle, |
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| 150 | G4double temperature) |
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| 151 | { |
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| 152 | G4int nIso = anEle->GetNumberOfIsotopes(); |
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| 153 | G4double xsection = 0; |
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| 154 | |
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| 155 | if (nIso) { |
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| 156 | G4double sig; |
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| 157 | G4IsotopeVector* isoVector = anEle->GetIsotopeVector(); |
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| 158 | G4double* abundVector = anEle->GetRelativeAbundanceVector(); |
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| 159 | G4double ZZ; |
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| 160 | G4double AA; |
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| 161 | |
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| 162 | for (G4int i = 0; i < nIso; i++) { |
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| 163 | ZZ = G4double( (*isoVector)[i]->GetZ() ); |
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| 164 | AA = G4double( (*isoVector)[i]->GetN() ); |
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| 165 | sig = GetIsoZACrossSection(aPart, ZZ, AA, temperature); |
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| 166 | xsection += sig*abundVector[i]; |
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| 167 | } |
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| 168 | |
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| 169 | } else { |
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| 170 | xsection = |
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| 171 | GetIsoZACrossSection(aPart, anEle->GetZ(), anEle->GetN(), |
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| 172 | temperature); |
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| 173 | } |
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| 174 | |
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| 175 | return xsection; |
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| 176 | } |
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