1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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10 | // * * |
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11 | // * Neither the authors of this software system, nor their employing * |
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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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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 | // 18-Sep-2003 First version is written by T. Koi |
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27 | // 10-Nov-2003 Bug fix at Cal. ke_per_n and D T. Koi |
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28 | // 12-Nov-2003 Add energy check at lower side T. Koi |
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29 | // 26-Dec-2006 Add isotope dependence D. Wright |
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30 | |
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31 | #include "G4IonsKoxCrossSection.hh" |
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32 | #include "G4ParticleTable.hh" |
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33 | #include "G4IonTable.hh" |
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34 | |
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35 | G4double G4IonsKoxCrossSection:: |
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36 | GetIsoZACrossSection(const G4DynamicParticle* aParticle, G4double ZZ, |
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37 | G4double AA, G4double /*temperature*/) |
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38 | { |
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39 | G4double xsection = 0.0; |
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40 | |
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41 | G4int Ap = aParticle->GetDefinition()->GetBaryonNumber(); |
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42 | G4int Zp = int ( aParticle->GetDefinition()->GetPDGCharge() / eplus + 0.5); |
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43 | G4double ke_per_N = aParticle->GetKineticEnergy() / Ap; |
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44 | |
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45 | // Apply energy check, if less than lower limit then 0 value is returned |
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46 | // if ( ke_per_N < lowerLimit ) return xsection; |
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47 | |
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48 | G4int At = int (AA + 0.5); |
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49 | G4int Zt = int (ZZ + 0.5 ); |
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50 | |
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51 | G4double one_third = 1.0 / 3.0; |
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52 | |
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53 | G4double cubicrAt = std::pow ( G4double(At) , G4double(one_third) ); |
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54 | G4double cubicrAp = std::pow ( G4double(Ap) , G4double(one_third) ); |
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55 | |
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56 | |
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57 | G4double Bc = Zt * Zp / ( ( rc / fermi ) * ( cubicrAp + cubicrAt ) ); // rc divide fermi |
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58 | G4double targ_mass = G4ParticleTable::GetParticleTable()->GetIonTable()->GetIonMass( Zt , At ); |
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59 | G4double proj_mass = aParticle->GetMass(); |
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60 | G4double proj_momentum = aParticle->GetMomentum().mag(); |
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61 | |
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62 | G4double Ecm = calEcm ( proj_mass , targ_mass , proj_momentum ); |
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63 | if( Ecm <= Bc) return xsection; |
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64 | |
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65 | G4double Rvol = r0 * ( cubicrAp + cubicrAt ); |
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66 | |
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67 | // G4double ke_per_N = aParticle->GetKineticEnergy() / Ap; |
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68 | G4double c = calCeValue ( ke_per_N / MeV ); |
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69 | |
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70 | G4double a = 1.85; |
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71 | G4double Rsurf = r0 * ( a * cubicrAp * cubicrAt / ( cubicrAp + cubicrAt ) - c); |
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72 | G4double D = 5.0 * ( At - 2 * Zt ) * Zp / ( Ap * At ); |
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73 | Rsurf = Rsurf + D * fermi; // multiply D by fermi |
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74 | |
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75 | G4double Rint = Rvol + Rsurf; |
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76 | |
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77 | xsection = pi * Rint * Rint * ( 1 - Bc / ( Ecm / MeV ) ); |
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78 | |
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79 | return xsection; |
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80 | } |
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81 | |
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82 | G4double G4IonsKoxCrossSection:: |
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83 | GetCrossSection(const G4DynamicParticle* aParticle, |
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84 | const G4Element* anElement, G4double temperature) |
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85 | { |
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86 | G4int nIso = anElement->GetNumberOfIsotopes(); |
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87 | G4double xsection = 0; |
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88 | |
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89 | if (nIso) { |
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90 | G4double sig; |
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91 | G4IsotopeVector* isoVector = anElement->GetIsotopeVector(); |
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92 | G4double* abundVector = anElement->GetRelativeAbundanceVector(); |
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93 | G4double ZZ; |
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94 | G4double AA; |
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95 | |
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96 | for (G4int i = 0; i < nIso; i++) { |
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97 | ZZ = G4double( (*isoVector)[i]->GetZ() ); |
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98 | AA = G4double( (*isoVector)[i]->GetN() ); |
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99 | sig = GetIsoZACrossSection(aParticle, ZZ, AA, temperature); |
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100 | xsection += sig*abundVector[i]; |
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101 | } |
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102 | |
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103 | } else { |
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104 | xsection = |
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105 | GetIsoZACrossSection(aParticle, anElement->GetZ(), anElement->GetN(), |
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106 | temperature); |
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107 | } |
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108 | |
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109 | return xsection; |
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110 | } |
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111 | |
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112 | |
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113 | G4double G4IonsKoxCrossSection::calEcm ( G4double mp , G4double mt , G4double Plab ) |
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114 | { |
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115 | G4double Elab = std::sqrt ( mp * mp + Plab * Plab ); |
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116 | G4double Ecm = std::sqrt ( mp * mp + mt * mt + 2 * Elab * mt ); |
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117 | G4double Pcm = Plab * mt / Ecm; |
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118 | G4double KEcm = std::sqrt ( Pcm * Pcm + mp * mp ) - mp; |
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119 | return KEcm; |
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120 | } |
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121 | |
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122 | |
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123 | G4double G4IonsKoxCrossSection::calCeValue( const G4double ke ) |
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124 | { |
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125 | // Calculate c value |
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126 | // This value is indepenent from projectile and target particle |
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127 | // ke is projectile kinetic energy per nucleon in the Lab system with MeV unit |
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128 | // fitting function is made by T. Koi |
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129 | // There are no data below 30 MeV/n in Kox et al., |
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130 | |
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131 | G4double Ce; |
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132 | G4double log10_ke = std::log10 ( ke ); |
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133 | if ( log10_ke > 1.5 ) |
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134 | { |
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135 | Ce = - 10.0 / std::pow ( G4double(log10_ke) , G4double(5) ) + 2.0; |
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136 | } |
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137 | else |
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138 | { |
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139 | Ce = ( - 10.0 / std::pow ( G4double(1.5) , G4double(5) ) + 2.0 ) / std::pow ( G4double(1.5) , G4double(3) ) * std::pow ( G4double(log10_ke) , G4double(3) ); |
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140 | |
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141 | } |
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142 | return Ce; |
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143 | } |
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