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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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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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21 | // * any work based on the software) you agree to acknowledge its * |
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24 | // ******************************************************************** |
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25 | // |
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26 | // |
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27 | // $Id: G4FissionProbability.cc,v 1.10 2010/11/17 20:22:46 vnivanch Exp $ |
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28 | // GEANT4 tag $Name: geant4-09-04-ref-00 $ |
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29 | // |
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30 | // Hadronic Process: Nuclear De-excitations |
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31 | // by V. Lara (Oct 1998) |
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32 | // |
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33 | // |
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34 | // J.M.Quesada (14 february 2009) bug fixed in fission width: missing parenthesis in the denominator |
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35 | |
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36 | |
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37 | #include "G4FissionProbability.hh" |
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38 | #include "G4PairingCorrection.hh" |
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39 | |
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40 | G4FissionProbability::G4FissionProbability() |
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41 | {} |
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42 | |
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43 | G4FissionProbability::~G4FissionProbability() |
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44 | {} |
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45 | |
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46 | |
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47 | G4double |
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48 | G4FissionProbability::EmissionProbability(const G4Fragment & fragment, |
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49 | G4double MaximalKineticEnergy) |
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50 | // Compute integrated probability of fission channel |
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51 | { |
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52 | if (MaximalKineticEnergy <= 0.0) return 0.0; |
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53 | G4int A = fragment.GetA_asInt(); |
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54 | G4int Z = fragment.GetZ_asInt(); |
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55 | G4double U = fragment.GetExcitationEnergy(); |
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56 | |
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57 | G4double Ucompound = U - |
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58 | G4PairingCorrection::GetInstance()->GetPairingCorrection(A,Z); |
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59 | |
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60 | G4double Ufission = U - |
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61 | G4PairingCorrection::GetInstance()->GetFissionPairingCorrection(A,Z); |
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62 | |
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63 | G4double SystemEntropy = |
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64 | 2.0*std::sqrt(theEvapLDP.LevelDensityParameter(A,Z,Ucompound)*Ucompound); |
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65 | |
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66 | G4double afission = theFissLDP.LevelDensityParameter(A,Z,Ufission); |
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67 | |
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68 | G4double Cf = 2.0*std::sqrt(afission*MaximalKineticEnergy); |
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69 | |
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70 | // G4double Q1 = 1.0 + (Cf - 1.0)*std::exp(Cf); |
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71 | // G4double Q2 = 4.0*pi*afission*std::exp(SystemEntropy); |
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72 | |
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73 | // G4double probability = Q1/Q2; |
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74 | |
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75 | G4double Exp1 = 0.0; |
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76 | if (SystemEntropy <= 160.0) { Exp1 = std::exp(-SystemEntropy); } |
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77 | // @@@@@@@@@@@@@@@@@ hpw changed max to min - cannot notify vicente now |
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78 | G4double Exp2 = std::exp( std::min(700.0,Cf-SystemEntropy) ); |
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79 | |
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80 | // JMQ 14/02/09 BUG fixed in fission probability (missing parenthesis |
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81 | // at denominator) |
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82 | //AH fix from Vincente: G4double probability = |
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83 | // (Exp1 + (1.0-Cf)*Exp2) / 4.0*pi*afission; |
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84 | // G4double probability = (Exp1 + (Cf-1.0)*Exp2) / 4.0*pi*afission; |
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85 | G4double probability = (Exp1 + (Cf-1.0)*Exp2) / (4.0*pi*afission); |
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86 | |
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87 | return probability; |
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88 | } |
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89 | |
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