[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 | // Implementation of the HETC88 code into Geant4. |
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| 28 | // Evaporation and De-excitation parts |
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| 29 | // T. Lampen, Helsinki Institute of Physics, May-2000 |
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| 30 | |
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| 31 | #include "G4BEChargedChannel.hh" |
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| 32 | |
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| 33 | |
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| 34 | G4BEChargedChannel::G4BEChargedChannel() |
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| 35 | { |
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| 36 | verboseLevel = 0; |
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| 37 | } |
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| 38 | |
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| 39 | |
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| 40 | G4BEChargedChannel::~G4BEChargedChannel() |
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| 41 | { |
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| 42 | } |
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| 43 | |
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| 44 | |
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| 45 | void G4BEChargedChannel::calculateProbability() |
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| 46 | { |
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| 47 | G4int residualZ = nucleusZ - particleZ; |
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| 48 | G4int residualA = nucleusA - particleA; |
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| 49 | |
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| 50 | // Check if nucleus is too small, if this evaporation channel |
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| 51 | // leads to an impossible residual nucleus or if there is no enough |
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| 52 | // energy. |
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| 53 | if ( nucleusA < 2.0 * particleA || |
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| 54 | nucleusZ < 2.0 * particleZ || |
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| 55 | residualA <= residualZ || |
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| 56 | excitationEnergy - getThresh() - correction < 0 ) |
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| 57 | { |
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| 58 | if ( verboseLevel >= 6 ) |
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| 59 | G4cout << "G4BEChargedChannel : calculateProbability for " << getName() << " = 0 " << G4endl; |
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| 60 | emissionProbability = 0; |
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| 61 | return; |
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| 62 | } |
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| 63 | |
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| 64 | // In HETC88 s-s0 was used in std::exp( s ), in which s0 was either 50 or |
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| 65 | // max(s_i), where i goes over all channels. |
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| 66 | |
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| 67 | G4double levelParam = getLevelDensityParameter(); |
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| 68 | G4double s = 2 * std::sqrt( levelParam * ( excitationEnergy - getThresh() - correction ) ); |
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| 69 | G4double constant = A / 2 * ( 2 * spin + 1 ) * ( 1 + coulombFactor() ); |
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| 70 | G4double eye1 = ( std::pow( s, 2. ) - 3 * s + 3 ) / ( 4 * std::pow( levelParam, 2. ) ) * std::exp( s ); |
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| 71 | |
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| 72 | emissionProbability = constant * std::pow( G4double(residualA), 0.6666666 ) * eye1; |
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| 73 | |
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| 74 | if ( verboseLevel >= 6 ) |
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| 75 | G4cout << "G4BEChargedChannel : calculateProbability for " << getName() << G4endl |
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| 76 | << " res A = " << residualA << G4endl |
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| 77 | << " res Z = " << residualZ << G4endl |
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| 78 | << " c*(c_i+1) = "<< constant << G4endl |
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| 79 | << " qmfactor = "<< qmFactor() << G4endl |
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| 80 | << " coulombfactor = "<< coulombFactor() << G4endl |
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| 81 | << " E = " << excitationEnergy << G4endl |
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| 82 | << " correction = " << correction << G4endl |
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| 83 | << " eye1 = " << eye1 << G4endl |
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| 84 | << " levelParam = " << levelParam << G4endl |
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| 85 | << " thresh = " << getThresh() << G4endl |
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| 86 | << " s = " << s << G4endl |
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| 87 | << " probability = " << emissionProbability << G4endl; |
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| 88 | |
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| 89 | return; |
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| 90 | } |
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| 91 | |
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| 92 | |
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| 93 | G4double G4BEChargedChannel::sampleKineticEnergy() |
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| 94 | { |
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| 95 | // G4double randExp1; |
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| 96 | // G4double randExp2; |
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| 97 | // G4double s; |
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| 98 | // G4double levelParam; |
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| 99 | // G4double kineticEnergyAv; |
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| 100 | // G4double kineticEnergy; |
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| 101 | |
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| 102 | // randExp1 = RandExponential::shoot( 1 ); |
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| 103 | // randExp2 = RandExponential::shoot( 1 ); |
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| 104 | // levelParam = getLevelDensityParameter(); |
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| 105 | // s = 2 * std::sqrt( levelParam * ( excitationEnergy - getThresh() - correction ) ); |
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| 106 | // kineticEnergyAv = 2 * ( std::pow( s, 3. ) - 6.0 * std::pow( s, 2. ) + 15.0 * s - 15.0 ) / |
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| 107 | // ( ( 2.0 * std::pow( s, 2. ) - 6.0 * s + 6.0 ) * levelParam ); |
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| 108 | |
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| 109 | // kineticEnergy = 0.5 * ( randExp1 + randExp2 ) * kineticEnergyAv + getThresh() - getQ(); |
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| 110 | |
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| 111 | // if ( verboseLevel >= 10 ) |
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| 112 | // G4cout << " G4BEChargedChannel : sampleKineticEnergy() " << G4endl |
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| 113 | // << " kinetic e = " << kineticEnergy << G4endl |
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| 114 | // << " average = " << kineticEnergyAv << G4endl |
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| 115 | // << " s = " << s << G4endl |
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| 116 | // << " levelParam = " << levelParam << G4endl |
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| 117 | // << " randExp1 = " << randExp1 << G4endl |
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| 118 | // << " randExp2 = " << randExp2 << G4endl; |
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| 119 | |
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| 120 | G4double levelParam; |
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| 121 | levelParam = getLevelDensityParameter(); |
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| 122 | |
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| 123 | const G4double xMax = excitationEnergy - getThresh() - correction; // maximum number |
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| 124 | const G4double xProb = ( - 1 + std::sqrt ( 1 + 4 * levelParam * xMax ) ) / ( 2 * levelParam ); // most probable value |
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| 125 | const G4double m = xProb * std::exp ( 2 * std::sqrt ( levelParam * ( xMax - xProb ) ) ); // maximum value of P(x) |
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| 126 | |
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| 127 | // Sample x according to density function P(x) with rejection method |
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| 128 | G4double r1; |
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| 129 | G4double r2; |
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| 130 | G4int koe=0; |
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| 131 | do |
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| 132 | { |
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| 133 | r1 = G4UniformRand() * xMax; |
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| 134 | r2 = G4UniformRand() * m; |
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| 135 | koe++; |
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| 136 | } |
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| 137 | while ( r1 * std::exp ( 2 * std::sqrt ( levelParam * ( xMax - r1 ) ) ) < r2 ); |
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| 138 | |
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| 139 | // G4cout << "Q ch " << koe << G4endl; |
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| 140 | G4double kineticEnergy = r1 + getCoulomb(); // add coulomb potential; |
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| 141 | |
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| 142 | if ( verboseLevel >= 10 ) |
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| 143 | G4cout << " G4BENeutronChannel : sampleKineticEnergy() " << G4endl |
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| 144 | << " kinetic n e = " << kineticEnergy << G4endl |
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| 145 | << " levelParam = " << levelParam << G4endl |
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| 146 | << " thresh= " << getThresh() << G4endl; |
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| 147 | |
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| 148 | return kineticEnergy; |
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| 149 | } |
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| 150 | |
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| 151 | |
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| 152 | G4double G4BEChargedChannel::coulombFactorForProton() |
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| 153 | { |
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| 154 | // Coefficient c_p:s for empirical cross section formula are |
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| 155 | // defined with the proton constant. See Dostrovsky, Phys. Rev., |
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| 156 | // vol. 116, 1959. |
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| 157 | G4double t[7] = { 0.08 , 0 , -0.06 , -0.1 , -0.1 , -0.1 , -0.1 }; |
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| 158 | G4int Z = nucleusZ - particleZ; |
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| 159 | |
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| 160 | if ( Z >= 70.0 ) return t[6]; |
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| 161 | if ( Z <= 10.0 ) return t[0]; |
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| 162 | |
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| 163 | // Linear interpolation |
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| 164 | G4int n = G4int( 0.1 * Z + 1.0 ); |
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| 165 | G4float x = ( 10 * n - Z ) * 0.1; |
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| 166 | G4double ret_val = x * t[n - 2] + ( 1.0 - x ) * t[n-1]; |
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| 167 | |
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| 168 | return ret_val; |
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| 169 | } |
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| 170 | |
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| 171 | |
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| 172 | G4double G4BEChargedChannel::qmFactorForProton() |
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| 173 | { |
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| 174 | // Coefficient k_p for empirical cross section formula are defined |
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| 175 | // with the proton constant. See Dostrovsky, Phys. Rev., vol. 116, |
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| 176 | // 1959 |
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| 177 | G4double t[7] = { 0.36, 0.51, 0.60, 0.66, 0.68, 0.69, 0.69 }; |
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| 178 | G4int Z = nucleusZ - particleZ; |
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| 179 | |
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| 180 | if ( Z >= 70.0 ) return t[6]; |
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| 181 | if ( Z <= 10.0 ) return t[0]; |
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| 182 | |
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| 183 | // Linear interpolation |
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| 184 | G4int n = G4int( 0.1 * Z + 1.0 ); |
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| 185 | G4float x = ( 10 * n - Z ) * 0.1; |
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| 186 | return x * t[n - 2] + ( 1.0 - x ) * t[n-1]; |
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| 187 | } |
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| 188 | |
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| 189 | |
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| 190 | G4double G4BEChargedChannel::qmFactorForAlpha() |
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| 191 | { |
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| 192 | // Coefficient k_alpha for empirical cross section formula presented |
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| 193 | // in Dostrovsky, Phys. Rev., vol. 116, 1959 |
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| 194 | |
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| 195 | G4double t[7] = { 0.77, 0.81, 0.85, 0.89, 0.93, 0.97, 1.00 }; |
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| 196 | G4int Z = nucleusZ - particleZ; |
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| 197 | |
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| 198 | if ( Z >= 70.0 ) return t[6]; |
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| 199 | if ( Z <= 10.0 ) return t[0]; |
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| 200 | |
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| 201 | // Linear interpolation |
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| 202 | G4int n = G4int( 0.1 * Z + 1.0 ); |
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| 203 | G4float x = ( 10 * n - Z ) * 0.1; |
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| 204 | return x * t[n - 2] + ( 1.0 - x ) * t[n-1]; |
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| 205 | } |
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