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1 // 2 // ******************************************************************** 3 // * License and Disclaimer * 4 // * * 5 // * The Geant4 software is copyright of the Copyright Holders of * 6 // * the Geant4 Collaboration. It is provided under the terms and * 7 // * conditions of the Geant4 Software License, included in the file * 8 // * LICENSE and available at http://cern.ch/geant4/license . These * 9 // * include a list of copyright holders. * 10 // * * 11 // * Neither the authors of this software system, nor their employing * 12 // * institutes,nor the agencies providing financial support for this * 13 // * work make any representation or warranty, express or implied, * 14 // * regarding this software system or assume any liability for its * 15 // * use. Please see the license in the file LICENSE and URL above * 16 // * for the full disclaimer and the limitation of liability. * 17 // * * 18 // * This code implementation is the result of the scientific and * 19 // * technical work of the GEANT4 collaboration. * 20 // * By using, copying, modifying or distributing the software (or * 21 // * any work based on the software) you agree to acknowledge its * 22 // * use in resulting scientific publications, and indicate your * 23 // * acceptance of all terms of the Geant4 Software license. * 24 // ******************************************************************** 25 // 26 // 27 // 28 // Hadronic Process: Nuclear De-excitations 29 // by V. Lara (Oct 1998) 30 // 31 //J. M. Quesada (May 2009): sigma_sym (SigmaS) tuned for spallation data. 32 //J. M. Quesada (30.10.09): retuning for IAEA spallation data 33 34 #include "G4FissionParameters.hh" 35 #include "G4SystemOfUnits.hh" 36 37 G4FissionParameters::G4FissionParameters() 38 : A1(134),A2(141),A3((A1 + A2)*0.5),As(0.0),Sigma1(0.0),Sigma2(0.0), 39 SigmaS(0.),w(0.0) 40 {} 41 42 G4FissionParameters::~G4FissionParameters() 43 {} 44 45 void G4FissionParameters::DefineParameters(G4int A, G4int Z, G4double ExEnergy, 46 G4double FissionBarrier) 47 { 48 // to avoid usage of units 49 G4double U = std::min(200., ExEnergy/CLHEP::MeV); 50 51 As = A*0.5; 52 53 if (A <= 235) { Sigma2 = 5.6; } 54 else { Sigma2 = 5.6 + 0.096*(A-235); } 55 56 Sigma1 = 0.5*Sigma2; 57 58 //JMQ 310509 59 // if (SigmaS > 20.0) SigmaS = 20.0; 60 // SigmaS*=1.3; 61 //JMQ 301009: retuning (after CEM transition prob.have been chosen as default) 62 SigmaS = 0.8*G4Exp(0.00553*U + 2.1386); 63 64 G4double wa = 0.0; 65 w = 0.0; 66 if (Z >= 90) { 67 if (U <= 16.25) { wa = G4Exp(0.5385*U-9.9564); } 68 else { wa = G4Exp(0.09197*U-2.7003); } 69 } else if (Z == 89) { 70 wa = G4Exp(0.09197*U-1.0808); 71 } else if (Z >= 82) { 72 G4double X = std::max(0.0, FissionBarrier/CLHEP::MeV - 7.5); 73 wa = G4Exp(0.09197*(U-X) - 1.0808); 74 } else { // Z < 82 75 w = 1001.0; 76 } 77 78 if (Z >= 82) { 79 G4double x1 = (A1-As)/Sigma1; 80 G4double x2 = (A2-As)/Sigma2; 81 G4double FasymAsym = 2*LocalExp(x2) + LocalExp(x1); 82 83 G4double x3 = (As-A3)/SigmaS; 84 G4double FsymA1A2 = LocalExp(x3); 85 86 G4double w1 = std::max(1.03*wa - FasymAsym, 0.0001); 87 G4double w2 = std::max(1.0 - FsymA1A2*wa, 0.0001); 88 89 w = w1/w2; 90 91 if (A < 227) { w *= G4Exp(0.3*(227-A)); } 92 } 93 } 94 95 96