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 // $Id$ 00027 // 00028 // Hadronic Process: Nuclear De-excitations 00029 // by V. Lara (Dec 1999) 00030 // 00031 // 14-11-2007 modified barrier by JMQ (test30) 00032 // 15-11-2010 V.Ivanchenko use G4Pow and cleanup 00033 00034 #include <sstream> 00035 00036 #include "G4CoulombBarrier.hh" 00037 #include "G4PhysicalConstants.hh" 00038 #include "G4SystemOfUnits.hh" 00039 #include "G4HadronicException.hh" 00040 #include "G4Pow.hh" 00041 00042 G4CoulombBarrier::G4CoulombBarrier(): G4VCoulombBarrier(1,0) 00043 {} 00044 00045 G4CoulombBarrier::G4CoulombBarrier(G4int anA, G4int aZ) 00046 : G4VCoulombBarrier(anA,aZ) 00047 {} 00048 00049 G4CoulombBarrier::~G4CoulombBarrier() 00050 {} 00051 00052 G4double G4CoulombBarrier::BarrierPenetrationFactor(G4double ) const 00053 { 00054 return 1.0; 00055 } 00056 00057 G4double G4CoulombBarrier::GetCoulombBarrier(const G4int ARes, const G4int ZRes, const G4double) const 00058 // Calculation of Coulomb potential energy (barrier) for outgoing fragment 00059 { 00060 G4double Barrier = 0.0; 00061 if (ZRes > ARes || ARes < 1) { 00062 std::ostringstream errOs; 00063 errOs << "G4CoulombBarrier::GetCoulombBarrier: "; 00064 errOs << "Wrong values for "; 00065 errOs << "residual nucleus A = " << ARes << " "; 00066 errOs << "and residual nucleus Z = " << ZRes << G4endl; 00067 00068 throw G4HadronicException(__FILE__, __LINE__, errOs.str()); 00069 } 00070 if (GetA() == 1 && GetZ() == 0) { 00071 Barrier = 0.0; // Neutron Coulomb Barrier is 0 00072 } else { 00073 00074 // JMQ: old coulomb barrier commented since it does not agree with Dostrovski's prescription 00075 // and too low barriers are obtained (for protons at least) 00076 // calculation of K penetration factor is correct 00077 // G4double CompoundRadius = CalcCompoundRadius(static_cast<G4double>(ZRes)); 00078 // Barrier = elm_coupling/CompoundRadius * static_cast<G4double>(GetZ())*static_cast<G4double>(ZRes)/ 00079 // (std::pow(static_cast<G4double>(GetA()),1./3.) + std::pow(static_cast<G4double>(ARes),1./3.)); 00080 00082 G4double rho=1.2*fermi; 00083 if(GetA()==1 && GetZ()==1){ rho=0.0;} 00084 00085 G4double RN=1.5*fermi; 00086 // VI cleanup 00087 Barrier=elm_coupling*(GetZ()*ZRes)/(RN * G4Pow::GetInstance()->Z13(ARes) + rho); 00088 00089 // Barrier penetration coeficient 00090 G4double K = BarrierPenetrationFactor(ZRes); 00091 00092 Barrier *= K; 00093 00094 // JMQ : the following statement has unknown origin and dimensionally is meaningless( energy divided by mass number in argument of sqrt function). Energy dependence of Coulomb barrier penetrability should be included in proper way (if needed..) 00095 // Barrier /= (1.0 + std::sqrt(U/(2.0*static_cast<G4double>(ARes)))); 00096 // 00097 } 00098 return Barrier; 00099 } 00100 00101 00102