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 // ------------------------------------------------------------------- 00028 // GEANT 4 class implementation file 00029 // 00030 // CERN, Geneva, Switzerland 00031 // 00032 // File name: G4AntiProtonField.cc 00033 // 00034 // Author: Alessandro Brunengo (Alessandro.Brunengo@ge.infn.it) 00035 // 00036 // Creation date: 5 June 2000 00037 // ------------------------------------------------------------------- 00038 00039 #include "G4AntiProtonField.hh" 00040 #include "G4PhysicalConstants.hh" 00041 #include "G4SystemOfUnits.hh" 00042 #include "G4NucleiProperties.hh" 00043 #include "G4VNuclearDensity.hh" 00044 #include "G4FermiMomentum.hh" 00045 #include "G4ParticleDefinition.hh" 00046 #include "G4AntiProton.hh" 00047 #include "G4HadTmpUtil.hh" 00048 00049 G4AntiProtonField::G4AntiProtonField(G4V3DNucleus * nucleus, G4double coeff) 00050 : G4VNuclearField(nucleus) 00051 { 00052 theCoeff = coeff; 00053 } 00054 00055 00056 G4AntiProtonField::~G4AntiProtonField() 00057 { } 00058 00059 00060 00061 00062 G4double G4AntiProtonField::GetField(const G4ThreeVector & aPosition) 00063 { 00064 // Field is 0 out of the nucleus! 00065 if(aPosition.mag() >= radius) return 0.0; 00066 00067 G4ParticleDefinition *anAntiProton = G4AntiProton::AntiProtonDefinition(); 00068 G4double antiProtonMass = anAntiProton->GetPDGMass(); 00069 00070 G4int A = theNucleus->GetMassNumber(); 00071 G4int Z = theNucleus->GetCharge(); 00072 G4double bindingEnergy = G4NucleiProperties::GetBindingEnergy(A, Z); 00073 G4double nucleusMass = Z*proton_mass_c2+(A-Z)*neutron_mass_c2+bindingEnergy; 00074 G4double reducedMass = antiProtonMass*nucleusMass/(antiProtonMass+nucleusMass); 00075 00076 G4double density = theNucleus->GetNuclearDensity()->GetDensity(aPosition); 00077 00078 return -2.*pi*hbarc*hbarc/reducedMass*(2.0)*theCoeff*density+GetBarrier(); 00079 } 00080 00081 00082 G4double G4AntiProtonField::GetBarrier() 00083 { 00084 G4int A = theNucleus->GetMassNumber(); 00085 G4int Z = theNucleus->GetCharge(); 00086 G4double coulombBarrier = (1.44/1.14) * MeV * Z / (1.0 + std::pow(A,1./3.)); 00087 return -coulombBarrier; 00088 } 00089 00090 00091 00092 00093 00094 00095