[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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[962] | 27 | // $Id: G4StatMFMicroPartition.cc,v 1.8 2008/07/25 11:20:47 vnivanch Exp $ |
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[1228] | 28 | // GEANT4 tag $Name: geant4-09-03 $ |
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[819] | 29 | // |
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| 30 | // by V. Lara |
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| 31 | // -------------------------------------------------------------------- |
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| 32 | |
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| 33 | #include "G4StatMFMicroPartition.hh" |
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| 34 | #include "G4HadronicException.hh" |
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| 35 | |
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| 36 | |
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| 37 | // Copy constructor |
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| 38 | G4StatMFMicroPartition::G4StatMFMicroPartition(const G4StatMFMicroPartition & ) |
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| 39 | { |
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| 40 | throw G4HadronicException(__FILE__, __LINE__, "G4StatMFMicroPartition::copy_constructor meant to not be accessable"); |
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| 41 | } |
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| 42 | |
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| 43 | // Operators |
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| 44 | |
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| 45 | G4StatMFMicroPartition & G4StatMFMicroPartition:: |
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| 46 | operator=(const G4StatMFMicroPartition & ) |
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| 47 | { |
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| 48 | throw G4HadronicException(__FILE__, __LINE__, "G4StatMFMicroPartition::operator= meant to not be accessable"); |
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| 49 | return *this; |
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| 50 | } |
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| 51 | |
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| 52 | |
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| 53 | G4bool G4StatMFMicroPartition::operator==(const G4StatMFMicroPartition & ) const |
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| 54 | { |
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| 55 | //throw G4HadronicException(__FILE__, __LINE__, "G4StatMFMicroPartition::operator== meant to not be accessable"); |
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| 56 | return false; |
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| 57 | } |
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| 58 | |
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| 59 | |
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| 60 | G4bool G4StatMFMicroPartition::operator!=(const G4StatMFMicroPartition & ) const |
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| 61 | { |
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| 62 | //throw G4HadronicException(__FILE__, __LINE__, "G4StatMFMicroPartition::operator!= meant to not be accessable"); |
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| 63 | return true; |
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| 64 | } |
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| 65 | |
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| 66 | |
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| 67 | |
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| 68 | void G4StatMFMicroPartition::CoulombFreeEnergy(const G4double anA) |
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| 69 | { |
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| 70 | // This Z independent factor in the Coulomb free energy |
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| 71 | G4double CoulombConstFactor = 1.0/std::pow(1.0+G4StatMFParameters::GetKappaCoulomb(),1.0/3.0); |
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| 72 | |
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| 73 | CoulombConstFactor = elm_coupling * (3./5.) * |
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| 74 | (1. - CoulombConstFactor)/G4StatMFParameters::Getr0(); |
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| 75 | |
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| 76 | // We use the aproximation Z_f ~ Z/A * A_f |
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| 77 | |
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| 78 | if (anA == 0 || anA == 1) |
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| 79 | { |
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| 80 | _theCoulombFreeEnergy.push_back(CoulombConstFactor*(theZ/theA)*(theZ/theA)); |
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| 81 | } |
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| 82 | else if (anA == 2 || anA == 3 || anA == 4) |
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| 83 | { |
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| 84 | // Z/A ~ 1/2 |
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| 85 | _theCoulombFreeEnergy.push_back(CoulombConstFactor*0.5*std::pow(anA,5./3.)); |
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| 86 | } |
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| 87 | else // anA > 4 |
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| 88 | { |
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| 89 | _theCoulombFreeEnergy.push_back(CoulombConstFactor*(theZ/theA)*(theZ/theA)* |
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| 90 | std::pow(anA,5./3.)); |
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| 91 | |
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| 92 | } |
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| 93 | } |
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| 94 | |
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| 95 | |
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| 96 | G4double G4StatMFMicroPartition::GetCoulombEnergy(void) |
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| 97 | { |
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| 98 | G4double CoulombFactor = 1.0/ |
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| 99 | std::pow(1.0+G4StatMFParameters::GetKappaCoulomb(),1.0/3.0); |
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| 100 | |
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| 101 | G4double CoulombEnergy = elm_coupling*(3./5.)*theZ*theZ*CoulombFactor/ |
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| 102 | (G4StatMFParameters::Getr0()*std::pow(static_cast<G4double>(theA),1./3.)); |
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| 103 | |
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| 104 | for (unsigned int i = 0; i < _thePartition.size(); i++) |
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| 105 | CoulombEnergy += _theCoulombFreeEnergy[i] - elm_coupling*(3./5.)* |
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| 106 | (theZ/theA)*(theZ/theA)*std::pow(static_cast<G4double>(_thePartition[i]),5./3.)/ |
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| 107 | G4StatMFParameters::Getr0(); |
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| 108 | |
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| 109 | return CoulombEnergy; |
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| 110 | } |
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| 111 | |
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| 112 | G4double G4StatMFMicroPartition::GetPartitionEnergy(const G4double T) |
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| 113 | { |
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| 114 | G4double CoulombFactor = 1.0/ |
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| 115 | std::pow(1.0+G4StatMFParameters::GetKappaCoulomb(),1.0/3.0); |
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| 116 | |
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| 117 | G4double PartitionEnergy = 0.0; |
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| 118 | |
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| 119 | |
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| 120 | // We use the aprox that Z_f ~ Z/A * A_f |
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| 121 | for (unsigned int i = 0; i < _thePartition.size(); i++) |
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| 122 | { |
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| 123 | if (_thePartition[i] == 0 || _thePartition[i] == 1) |
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| 124 | { |
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| 125 | PartitionEnergy += _theCoulombFreeEnergy[i]; |
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| 126 | } |
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| 127 | else if (_thePartition[i] == 2) |
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| 128 | { |
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| 129 | PartitionEnergy += |
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| 130 | -2.796 // Binding Energy of deuteron ?????? |
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| 131 | + _theCoulombFreeEnergy[i]; |
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| 132 | } |
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| 133 | else if (_thePartition[i] == 3) |
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| 134 | { |
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| 135 | PartitionEnergy += |
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| 136 | -9.224 // Binding Energy of trtion/He3 ?????? |
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| 137 | + _theCoulombFreeEnergy[i]; |
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| 138 | } |
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| 139 | else if (_thePartition[i] == 4) |
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| 140 | { |
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| 141 | PartitionEnergy += |
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| 142 | -30.11 // Binding Energy of ALPHA ?????? |
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| 143 | + _theCoulombFreeEnergy[i] |
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| 144 | + 4.*T*T/InvLevelDensity(4.); |
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| 145 | } |
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| 146 | else |
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| 147 | { |
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| 148 | PartitionEnergy += |
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| 149 | //Volume term |
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| 150 | (- G4StatMFParameters::GetE0() + |
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| 151 | T*T/InvLevelDensity(_thePartition[i])) |
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| 152 | *_thePartition[i] + |
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| 153 | |
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| 154 | // Symmetry term |
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| 155 | G4StatMFParameters::GetGamma0()* |
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| 156 | (1.0-2.0*theZ/theA)*(1.0-2.0*theZ/theA)*_thePartition[i] + |
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| 157 | |
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| 158 | // Surface term |
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| 159 | (G4StatMFParameters::Beta(T) - T*G4StatMFParameters::DBetaDT(T))* |
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| 160 | std::pow(static_cast<G4double>(_thePartition[i]),2./3.) + |
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| 161 | |
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| 162 | // Coulomb term |
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| 163 | _theCoulombFreeEnergy[i]; |
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| 164 | } |
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| 165 | } |
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| 166 | |
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| 167 | PartitionEnergy += elm_coupling*(3./5.)*theZ*theZ*CoulombFactor/ |
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| 168 | (G4StatMFParameters::Getr0()*std::pow(static_cast<G4double>(theA),1./3.)) |
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| 169 | + (3./2.)*T*(_thePartition.size()-1); |
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| 170 | |
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| 171 | return PartitionEnergy; |
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| 172 | } |
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| 173 | |
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| 174 | |
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| 175 | G4double G4StatMFMicroPartition::CalcPartitionTemperature(const G4double U, |
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| 176 | const G4double FreeInternalE0) |
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| 177 | { |
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| 178 | G4double PartitionEnergy = GetPartitionEnergy(0.0); |
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| 179 | |
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| 180 | // If this happens, T = 0 MeV, which means that probability for this |
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| 181 | // partition will be 0 |
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| 182 | if (std::abs(U + FreeInternalE0 - PartitionEnergy) < 0.003) return -1.0; |
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| 183 | |
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| 184 | // Calculate temperature by midpoint method |
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| 185 | |
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| 186 | // Bracketing the solution |
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| 187 | G4double Ta = 0.001; |
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| 188 | G4double Tb = std::max(std::sqrt(8.0*U/theA),0.0012*MeV); |
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| 189 | G4double Tmid = 0.0; |
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| 190 | |
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| 191 | G4double Da = (U + FreeInternalE0 - GetPartitionEnergy(Ta))/U; |
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| 192 | G4double Db = (U + FreeInternalE0 - GetPartitionEnergy(Tb))/U; |
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| 193 | |
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| 194 | G4int maxit = 0; |
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| 195 | while (Da*Db > 0.0 && maxit < 1000) |
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| 196 | { |
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| 197 | ++maxit; |
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| 198 | Tb += 0.5*Tb; |
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| 199 | Db = (U + FreeInternalE0 - GetPartitionEnergy(Tb))/U; |
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| 200 | } |
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| 201 | |
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| 202 | G4double eps = 1.0e-14*std::abs(Ta-Tb); |
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| 203 | |
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| 204 | for (G4int i = 0; i < 1000; i++) |
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| 205 | { |
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| 206 | Tmid = (Ta+Tb)/2.0; |
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| 207 | if (std::abs(Ta-Tb) <= eps) return Tmid; |
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| 208 | G4double Dmid = (U + FreeInternalE0 - GetPartitionEnergy(Tmid))/U; |
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| 209 | if (std::abs(Dmid) < 0.003) return Tmid; |
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| 210 | if (Da*Dmid < 0.0) |
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| 211 | { |
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| 212 | Tb = Tmid; |
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| 213 | Db = Dmid; |
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| 214 | } |
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| 215 | else |
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| 216 | { |
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| 217 | Ta = Tmid; |
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| 218 | Da = Dmid; |
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| 219 | } |
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| 220 | } |
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| 221 | // if we arrive here the temperature could not be calculated |
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| 222 | G4cerr << "G4StatMFMicroPartition::CalcPartitionTemperature: I can't calculate the temperature" |
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| 223 | << G4endl; |
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| 224 | // and set probability to 0 returning T < 0 |
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| 225 | return -1.0; |
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| 226 | |
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| 227 | } |
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| 228 | |
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| 229 | |
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| 230 | G4double G4StatMFMicroPartition::CalcPartitionProbability(const G4double U, |
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| 231 | const G4double FreeInternalE0, |
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| 232 | const G4double SCompound) |
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| 233 | { |
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| 234 | G4double T = CalcPartitionTemperature(U,FreeInternalE0); |
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| 235 | if ( T <= 0.0) return _Probability = 0.0; |
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| 236 | _Temperature = T; |
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| 237 | |
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| 238 | |
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| 239 | // Factorial of fragment multiplicity |
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| 240 | G4double Fact = 1.0; |
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| 241 | unsigned int i; |
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| 242 | for (i = 0; i < _thePartition.size() - 1; i++) |
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| 243 | { |
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| 244 | G4double f = 1.0; |
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| 245 | for (unsigned int ii = i+1; i< _thePartition.size(); i++) |
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| 246 | { |
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| 247 | if (_thePartition[i] == _thePartition[ii]) f++; |
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| 248 | } |
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| 249 | Fact *= f; |
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| 250 | } |
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| 251 | |
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| 252 | G4double ProbDegeneracy = 1.0; |
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| 253 | G4double ProbA32 = 1.0; |
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| 254 | |
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| 255 | for (i = 0; i < _thePartition.size(); i++) |
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| 256 | { |
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| 257 | ProbDegeneracy *= GetDegeneracyFactor(static_cast<G4int>(_thePartition[i])); |
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| 258 | ProbA32 *= static_cast<G4double>(_thePartition[i])* |
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| 259 | std::sqrt(static_cast<G4double>(_thePartition[i])); |
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| 260 | } |
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| 261 | |
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| 262 | // Compute entropy |
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| 263 | G4double PartitionEntropy = 0.0; |
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| 264 | for (i = 0; i < _thePartition.size(); i++) |
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| 265 | { |
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| 266 | // interaction entropy for alpha |
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| 267 | if (_thePartition[i] == 4) |
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| 268 | { |
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| 269 | PartitionEntropy += |
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| 270 | 2.0*T*_thePartition[i]/InvLevelDensity(_thePartition[i]); |
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| 271 | } |
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| 272 | // interaction entropy for Af > 4 |
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| 273 | else if (_thePartition[i] > 4) |
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| 274 | { |
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| 275 | PartitionEntropy += |
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| 276 | 2.0*T*_thePartition[i]/InvLevelDensity(_thePartition[i]) |
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| 277 | - G4StatMFParameters::DBetaDT(T) |
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| 278 | * std::pow(static_cast<G4double>(_thePartition[i]),2.0/3.0); |
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| 279 | } |
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| 280 | } |
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| 281 | |
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| 282 | // Thermal Wave Lenght = std::sqrt(2 pi hbar^2 / nucleon_mass T) |
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| 283 | G4double ThermalWaveLenght3 = 16.15*fermi/std::sqrt(T); |
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| 284 | ThermalWaveLenght3 = ThermalWaveLenght3*ThermalWaveLenght3*ThermalWaveLenght3; |
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| 285 | |
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| 286 | // Translational Entropy |
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| 287 | G4double kappa = (1. + elm_coupling*(std::pow(static_cast<G4double>(_thePartition.size()),1./3.)-1.0) |
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| 288 | /(G4StatMFParameters::Getr0()*std::pow(static_cast<G4double>(theA),1./3.))); |
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| 289 | kappa = kappa*kappa*kappa; |
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| 290 | kappa -= 1.; |
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| 291 | G4double V0 = (4./3.)*pi*theA*G4StatMFParameters::Getr0()*G4StatMFParameters::Getr0()* |
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| 292 | G4StatMFParameters::Getr0(); |
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| 293 | G4double FreeVolume = kappa*V0; |
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| 294 | G4double TranslationalS = std::max(0.0, std::log(ProbA32/Fact) + |
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| 295 | (_thePartition.size()-1.0)*std::log(FreeVolume/ThermalWaveLenght3) + |
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| 296 | 1.5*(_thePartition.size()-1.0) - (3./2.)*std::log(theA)); |
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| 297 | |
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| 298 | PartitionEntropy += std::log(ProbDegeneracy) + TranslationalS; |
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| 299 | _Entropy = PartitionEntropy; |
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| 300 | |
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| 301 | // And finally compute probability of fragment configuration |
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| 302 | G4double exponent = PartitionEntropy-SCompound; |
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| 303 | if (exponent > 700.0) exponent = 700.0; |
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| 304 | return _Probability = std::exp(exponent); |
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| 305 | } |
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| 306 | |
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| 307 | |
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| 308 | |
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| 309 | G4double G4StatMFMicroPartition::GetDegeneracyFactor(const G4int A) |
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| 310 | { |
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| 311 | // Degeneracy factors are statistical factors |
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| 312 | // DegeneracyFactor for nucleon is (2S_n + 1)(2I_n + 1) = 4 |
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| 313 | G4double DegFactor = 0; |
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| 314 | if (A > 4) DegFactor = 1.0; |
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| 315 | else if (A == 1) DegFactor = 4.0; // nucleon |
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| 316 | else if (A == 2) DegFactor = 3.0; // Deuteron |
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| 317 | else if (A == 3) DegFactor = 2.0+2.0; // Triton + He3 |
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| 318 | else if (A == 4) DegFactor = 1.0; // alpha |
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| 319 | return DegFactor; |
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| 320 | } |
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| 321 | |
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| 322 | |
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| 323 | G4StatMFChannel * G4StatMFMicroPartition::ChooseZ(const G4double A0, const G4double Z0, const G4double MeanT) |
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| 324 | // Gives fragments charges |
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| 325 | { |
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| 326 | std::vector<G4int> FragmentsZ; |
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| 327 | |
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| 328 | G4int ZBalance = 0; |
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| 329 | do |
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| 330 | { |
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| 331 | G4double CC = G4StatMFParameters::GetGamma0()*8.0; |
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| 332 | G4int SumZ = 0; |
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| 333 | for (unsigned int i = 0; i < _thePartition.size(); i++) |
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| 334 | { |
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| 335 | G4double ZMean; |
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| 336 | G4double Af = _thePartition[i]; |
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| 337 | if (Af > 1.5 && Af < 4.5) ZMean = 0.5*Af; |
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| 338 | else ZMean = Af*Z0/A0; |
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| 339 | G4double ZDispersion = std::sqrt(Af * MeanT/CC); |
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| 340 | G4int Zf; |
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| 341 | do |
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| 342 | { |
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| 343 | Zf = static_cast<G4int>(G4RandGauss::shoot(ZMean,ZDispersion)); |
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| 344 | } |
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| 345 | while (Zf < 0 || Zf > Af); |
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| 346 | FragmentsZ.push_back(Zf); |
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| 347 | SumZ += Zf; |
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| 348 | } |
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| 349 | ZBalance = static_cast<G4int>(Z0) - SumZ; |
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| 350 | } |
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| 351 | while (std::abs(ZBalance) > 1.1); |
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| 352 | FragmentsZ[0] += ZBalance; |
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| 353 | |
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| 354 | G4StatMFChannel * theChannel = new G4StatMFChannel; |
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| 355 | for (unsigned int i = 0; i < _thePartition.size(); i++) |
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| 356 | { |
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| 357 | theChannel->CreateFragment(_thePartition[i],FragmentsZ[i]); |
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| 358 | } |
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| 359 | |
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| 360 | return theChannel; |
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| 361 | } |
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