00001 // 00002 // ******************************************************************** 00003 // * License and Disclaimer * 00004 // * * 00005 // * The Geant4 software is copyright of the Copyright Holders of * 00006 // * the Geant4 Collaboration. It is provided under the terms and * 00007 // * conditions of the Geant4 Software License, included in the file * 00008 // * LICENSE and available at http://cern.ch/geant4/license . These * 00009 // * include a list of copyright holders. * 00010 // * * 00011 // * Neither the authors of this software system, nor their employing * 00012 // * institutes,nor the agencies providing financial support for this * 00013 // * work make any representation or warranty, express or implied, * 00014 // * regarding this software system or assume any liability for its * 00015 // * use. Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // 00027 // $Id$ 00028 // 00029 // Hadronic Process: Nuclear De-excitations 00030 // by V. Lara (Oct 1998) 00031 // 00032 // 00033 // J.M.Quesada (14 february 2009) bug fixed in fission width: missing parenthesis in the denominator 00034 00035 00036 #include "G4FissionProbability.hh" 00037 #include "G4PhysicalConstants.hh" 00038 #include "G4PairingCorrection.hh" 00039 00040 G4FissionProbability::G4FissionProbability() 00041 {} 00042 00043 G4FissionProbability::~G4FissionProbability() 00044 {} 00045 00046 00047 G4double 00048 G4FissionProbability::EmissionProbability(const G4Fragment & fragment, 00049 G4double MaximalKineticEnergy) 00050 // Compute integrated probability of fission channel 00051 { 00052 if (MaximalKineticEnergy <= 0.0) return 0.0; 00053 G4int A = fragment.GetA_asInt(); 00054 G4int Z = fragment.GetZ_asInt(); 00055 G4double U = fragment.GetExcitationEnergy(); 00056 00057 G4double Ucompound = U - 00058 G4PairingCorrection::GetInstance()->GetPairingCorrection(A,Z); 00059 00060 G4double Ufission = U - 00061 G4PairingCorrection::GetInstance()->GetFissionPairingCorrection(A,Z); 00062 00063 G4double SystemEntropy = 00064 2.0*std::sqrt(theEvapLDP.LevelDensityParameter(A,Z,Ucompound)*Ucompound); 00065 00066 G4double afission = theFissLDP.LevelDensityParameter(A,Z,Ufission); 00067 00068 G4double Cf = 2.0*std::sqrt(afission*MaximalKineticEnergy); 00069 00070 // G4double Q1 = 1.0 + (Cf - 1.0)*std::exp(Cf); 00071 // G4double Q2 = 4.0*pi*afission*std::exp(SystemEntropy); 00072 00073 // G4double probability = Q1/Q2; 00074 00075 G4double Exp1 = 0.0; 00076 if (SystemEntropy <= 160.0) { Exp1 = std::exp(-SystemEntropy); } 00077 // @@@@@@@@@@@@@@@@@ hpw changed max to min - cannot notify vicente now 00078 G4double Exp2 = std::exp( std::min(700.0,Cf-SystemEntropy) ); 00079 00080 // JMQ 14/02/09 BUG fixed in fission probability (missing parenthesis 00081 // at denominator) 00082 //AH fix from Vincente: G4double probability = 00083 // (Exp1 + (1.0-Cf)*Exp2) / 4.0*pi*afission; 00084 // G4double probability = (Exp1 + (Cf-1.0)*Exp2) / 4.0*pi*afission; 00085 G4double probability = (Exp1 + (Cf-1.0)*Exp2) / (4.0*pi*afission); 00086 00087 return probability; 00088 } 00089