1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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4 | // * * |
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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 | // $Id: G4ProtonEvaporationProbability.cc,v 1.17 2010/11/17 11:06:03 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-04-ref-00 $ |
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28 | // |
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29 | // J.M. Quesada (August2008). Based on: |
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30 | // |
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31 | // Hadronic Process: Nuclear De-excitations |
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32 | // by V. Lara (Oct 1998) |
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33 | // |
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34 | // Modified: |
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35 | // 03-09-2008 J.M. Quesada for external choice of inverse cross section option |
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36 | // 17-11-2010 V.Ivanchenko integer Z and A |
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37 | |
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38 | #include "G4ProtonEvaporationProbability.hh" |
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39 | |
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40 | G4ProtonEvaporationProbability::G4ProtonEvaporationProbability() : |
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41 | G4EvaporationProbability(1,1,2,&theCoulombBarrier) // A,Z,Gamma,&theCoulombBarrier |
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42 | {} |
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43 | |
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44 | G4ProtonEvaporationProbability::~G4ProtonEvaporationProbability() |
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45 | {} |
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46 | |
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47 | G4double G4ProtonEvaporationProbability::CalcAlphaParam(const G4Fragment & fragment) |
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48 | { return 1.0 + CCoeficient(fragment.GetZ_asInt()-GetZ());} |
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49 | |
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50 | G4double G4ProtonEvaporationProbability::CalcBetaParam(const G4Fragment & ) |
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51 | { return 0.0; } |
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52 | |
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53 | G4double G4ProtonEvaporationProbability::CCoeficient(G4int aZ) |
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54 | { |
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55 | // Data comes from |
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56 | // Dostrovsky, Fraenkel and Friedlander |
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57 | // Physical Review, vol 116, num. 3 1959 |
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58 | // |
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59 | // const G4int size = 5; |
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60 | // G4double Zlist[5] = { 10.0, 20.0, 30.0, 50.0, 70.0}; |
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61 | // G4double Cp[5] = { 0.50, 0.28, 0.20, 0.15, 0.10}; |
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62 | G4double C = 0.0; |
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63 | |
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64 | if (aZ >= 70) { |
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65 | C = 0.10; |
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66 | } else { |
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67 | C = ((((0.15417e-06*aZ) - 0.29875e-04)*aZ + 0.21071e-02)*aZ - 0.66612e-01)*aZ + 0.98375; |
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68 | } |
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69 | |
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70 | return C; |
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71 | |
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72 | } |
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73 | |
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74 | /////////////////////////////////////////////////////////////////////////////////// |
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75 | //J. M. Quesada (Dec 2007-June 2008): New inverse reaction cross sections for protons |
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76 | //OPT=0 Dostrovski's parameterization |
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77 | //OPT=1 Chatterjee's parameterization |
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78 | //OPT=2,4 Wellisch's parameterization |
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79 | //OPT=3 Kalbach's parameterization |
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80 | // |
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81 | G4double |
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82 | G4ProtonEvaporationProbability::CrossSection(const G4Fragment & fragment, G4double K) |
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83 | { |
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84 | // G4cout<<" In G4ProtonEVaporationProbability OPTxs="<<OPTxs<<G4endl; |
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85 | // G4cout<<" In G4ProtonEVaporationProbability useSICB="<<useSICB<<G4endl; |
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86 | |
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87 | theA=GetA(); |
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88 | theZ=GetZ(); |
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89 | ResidualA=fragment.GetA_asInt()-theA; |
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90 | ResidualZ=fragment.GetZ_asInt()-theZ; |
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91 | |
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92 | ResidualAthrd=fG4pow->Z13(ResidualA); |
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93 | FragmentA=fragment.GetA_asInt(); |
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94 | FragmentAthrd=fG4pow->Z13(FragmentA); |
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95 | |
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96 | U=fragment.GetExcitationEnergy(); |
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97 | |
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98 | if (OPTxs==0) {std::ostringstream errOs; |
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99 | errOs << "We should'n be here (OPT =0) at evaporation cross section calculation (protons)!!" <<G4endl; |
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100 | throw G4HadronicException(__FILE__, __LINE__, errOs.str()); |
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101 | return 0.;} |
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102 | else if( OPTxs==1 ) return GetOpt1( K); |
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103 | else if( OPTxs==2 ||OPTxs==4) return GetOpt2( K); |
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104 | else if (OPTxs==3 ) return GetOpt3( K); |
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105 | else{ |
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106 | std::ostringstream errOs; |
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107 | errOs << "BAD PROTON CROSS SECTION OPTION AT EVAPORATION!!" <<G4endl; |
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108 | throw G4HadronicException(__FILE__, __LINE__, errOs.str()); |
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109 | return 0.; |
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110 | } |
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111 | } |
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112 | |
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113 | //********************* OPT=1 : Chatterjee's cross section ********************* |
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114 | //(fitting to cross section from Bechetti & Greenles OM potential) |
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115 | |
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116 | G4double G4ProtonEvaporationProbability::GetOpt1(G4double K) |
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117 | { |
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118 | G4double Kc=K; |
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119 | |
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120 | // JMQ xsec is set constat above limit of validity |
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121 | if (K > 50*MeV) { Kc = 50*MeV; } |
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122 | |
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123 | G4double landa, landa0, landa1, mu, mu0, mu1,nu, nu0, nu1, nu2,xs; |
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124 | G4double p, p0, p1, p2,Ec,delta,q,r,ji; |
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125 | |
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126 | p0 = 15.72; |
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127 | p1 = 9.65; |
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128 | p2 = -449.0; |
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129 | landa0 = 0.00437; |
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130 | landa1 = -16.58; |
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131 | mu0 = 244.7; |
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132 | mu1 = 0.503; |
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133 | nu0 = 273.1; |
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134 | nu1 = -182.4; |
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135 | nu2 = -1.872; |
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136 | delta=0.; |
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137 | |
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138 | Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta); |
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139 | p = p0 + p1/Ec + p2/(Ec*Ec); |
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140 | landa = landa0*ResidualA + landa1; |
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141 | |
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142 | G4double resmu1 = fG4pow->powZ(ResidualA,mu1); |
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143 | mu = mu0*resmu1; |
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144 | nu = resmu1*(nu0 + nu1*Ec + nu2*(Ec*Ec)); |
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145 | q = landa - nu/(Ec*Ec) - 2*p*Ec; |
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146 | r = mu + 2*nu/Ec + p*(Ec*Ec); |
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147 | |
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148 | ji=std::max(Kc,Ec); |
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149 | if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;} |
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150 | else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;} |
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151 | if (xs <0.0) {xs=0.0;} |
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152 | |
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153 | return xs; |
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154 | } |
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155 | |
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156 | //************* OPT=2 : Welisch's proton reaction cross section *************** |
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157 | |
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158 | G4double G4ProtonEvaporationProbability::GetOpt2(G4double K) |
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159 | { |
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160 | |
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161 | G4double eekin,ekin,ff1,ff2,ff3,r0,fac,fac1,fac2,b0,xine_th(0); |
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162 | |
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163 | // This is redundant when the Coulomb barrier is overimposed to all |
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164 | // cross sections |
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165 | // It should be kept when Coulomb barrier only imposed at OPTxs=2 |
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166 | |
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167 | if(!useSICB && K<=theCoulombBarrier.GetCoulombBarrier(ResidualA,ResidualZ,U)) |
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168 | { return 0.0; } |
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169 | |
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170 | eekin=K; |
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171 | G4int rnneu=ResidualA-ResidualZ; |
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172 | ekin=eekin/1000; |
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173 | r0=1.36*1.e-15; |
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174 | fac=pi*r0*r0; |
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175 | b0=2.247-0.915*(1.-1./ResidualAthrd); |
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176 | fac1=b0*(1.-1./ResidualAthrd); |
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177 | fac2=1.; |
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178 | if(rnneu > 1.5) { fac2 = fG4pow->logZ(rnneu); } |
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179 | xine_th= 1.e+31*fac*fac2*(1.+ResidualAthrd-fac1); |
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180 | xine_th=(1.-0.15*std::exp(-ekin))*xine_th/(1.00-0.0007*ResidualA); |
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181 | ff1=0.70-0.0020*ResidualA; |
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182 | ff2=1.00+1/G4double(ResidualA); |
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183 | ff3=0.8+18/G4double(ResidualA)-0.002*ResidualA; |
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184 | fac=1.-(1./(1.+std::exp(-8.*ff1*(std::log10(ekin)+1.37*ff2)))); |
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185 | xine_th=xine_th*(1.+ff3*fac); |
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186 | ff1=1.-1/G4double(ResidualA)-0.001*ResidualA; |
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187 | ff2=1.17-2.7/G4double(ResidualA)-0.0014*ResidualA; |
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188 | fac=-8.*ff1*(std::log10(ekin)+2.0*ff2); |
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189 | fac=1./(1.+std::exp(fac)); |
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190 | xine_th=xine_th*fac; |
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191 | if (xine_th < 0.0){ |
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192 | std::ostringstream errOs; |
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193 | G4cout<<"WARNING: negative Wellisch cross section "<<G4endl; |
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194 | errOs << "RESIDUAL: A=" << ResidualA << " Z=" << ResidualZ <<G4endl; |
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195 | errOs <<" xsec("<<ekin<<" MeV) ="<<xine_th <<G4endl; |
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196 | throw G4HadronicException(__FILE__, __LINE__, errOs.str()); |
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197 | } |
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198 | return xine_th; |
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199 | } |
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200 | |
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201 | // *********** OPT=3 : Kalbach's cross sections (from PRECO code)************* |
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202 | G4double G4ProtonEvaporationProbability::GetOpt3(const G4double K) |
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203 | { |
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204 | // ** p from becchetti and greenlees (but modified with sub-barrier |
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205 | // ** correction function and xp2 changed from -449) |
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206 | |
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207 | G4double landa, landa0, landa1, mu, mu0, mu1,nu, nu0, nu1, nu2; |
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208 | G4double p, p0, p1, p2; |
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209 | p0 = 15.72; |
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210 | p1 = 9.65; |
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211 | p2 = -300.; |
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212 | landa0 = 0.00437; |
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213 | landa1 = -16.58; |
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214 | mu0 = 244.7; |
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215 | mu1 = 0.503; |
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216 | nu0 = 273.1; |
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217 | nu1 = -182.4; |
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218 | nu2 = -1.872; |
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219 | |
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220 | // parameters for proton cross section refinement |
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221 | G4double afit,bfit,a2,b2; |
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222 | afit=-0.0785656; |
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223 | bfit=5.10789; |
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224 | a2= -0.00089076; |
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225 | b2= 0.0231597; |
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226 | |
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227 | G4double ec,ecsq,xnulam,etest(0.),ra(0.),a,w,c,signor(1.),signor2,sig; |
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228 | G4double b,ecut,cut,ecut2,geom,elab; |
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229 | |
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230 | G4double flow = 1.e-18; |
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231 | G4double spill= 1.e+18; |
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232 | |
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233 | if (ResidualA <= 60) { signor = 0.92; } |
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234 | else if (ResidualA < 100) { signor = 0.8 + ResidualA*0.002; } |
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235 | |
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236 | ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra); |
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237 | ecsq = ec * ec; |
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238 | p = p0 + p1/ec + p2/ecsq; |
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239 | landa = landa0*ResidualA + landa1; |
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240 | a = fG4pow->powZ(ResidualA,mu1); |
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241 | mu = mu0 * a; |
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242 | nu = a* (nu0+nu1*ec+nu2*ecsq); |
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243 | |
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244 | c =std::min(3.15,ec*0.5); |
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245 | w = 0.7 * c / 3.15; |
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246 | |
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247 | xnulam = nu / landa; |
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248 | if (xnulam > spill) { xnulam=0.; } |
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249 | if (xnulam >= flow) { etest =std::sqrt(xnulam) + 7.; } |
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250 | |
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251 | a = -2.*p*ec + landa - nu/ecsq; |
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252 | b = p*ecsq + mu + 2.*nu/ec; |
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253 | ecut = 0.; |
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254 | cut = a*a - 4.*p*b; |
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255 | if (cut > 0.) { ecut = std::sqrt(cut); } |
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256 | ecut = (ecut-a) / (p+p); |
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257 | ecut2 = ecut; |
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258 | //JMQ 290310 for avoiding unphysical increase below minimum (at ecut) |
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259 | // ecut<0 means that there is no cut with energy axis, i.e. xs is set |
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260 | // to 0 bellow minimum |
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261 | // if (cut < 0.) ecut2 = ecut - 2.; |
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262 | if (cut < 0.) { ecut2 = ecut; } |
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263 | elab = K * FragmentA /G4double(ResidualA); |
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264 | sig = 0.; |
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265 | if (elab <= ec) { //start for E<Ec |
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266 | if (elab > ecut2) { sig = (p*elab*elab+a*elab+b) * signor; } |
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267 | |
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268 | signor2 = (ec-elab-c) / w; |
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269 | signor2 = 1. + std::exp(signor2); |
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270 | sig = sig / signor2; |
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271 | } //end for E<=Ec |
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272 | else{ //start for E>Ec |
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273 | sig = (landa*elab+mu+nu/elab) * signor; |
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274 | geom = 0.; |
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275 | |
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276 | if (xnulam < flow || elab < etest) |
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277 | { |
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278 | if (sig <0.0) {sig=0.0;} |
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279 | return sig; |
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280 | } |
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281 | geom = std::sqrt(theA*K); |
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282 | geom = 1.23*ResidualAthrd + ra + 4.573/geom; |
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283 | geom = 31.416 * geom * geom; |
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284 | sig = std::max(geom,sig); |
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285 | |
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286 | } //end for E>Ec |
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287 | return sig; |
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288 | } |
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289 | |
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