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: G4KM_OpticalEqRhs.cc 00033 // 00034 // Author: Alessandro Brunengo (Alessandro.Brunengo@ge.infn.it) 00035 // 00036 // Creation date: 5 June 2000 00037 // ------------------------------------------------------------------- 00038 00039 #include "G4KM_OpticalEqRhs.hh" 00040 #include "G4PhysicalConstants.hh" 00041 #include "G4NucleiProperties.hh" 00042 #include "G4VNuclearDensity.hh" 00043 #include "G4HadTmpUtil.hh" 00044 00045 G4KM_OpticalEqRhs::G4KM_OpticalEqRhs(G4KM_DummyField *field, 00046 G4V3DNucleus * nucleus) : 00047 G4Mag_EqRhs(field), theNucleus(nucleus) 00048 { 00049 theFactor = 0; 00050 theMass = 0; 00051 } 00052 00053 00054 void G4KM_OpticalEqRhs::SetFactor(G4double mass, G4double opticalParameter) 00055 { 00056 G4double A = theNucleus->GetMassNumber(); 00057 G4double Z = theNucleus->GetCharge(); 00058 G4double bindingEnergy = G4NucleiProperties::GetBindingEnergy(G4lrint(A), G4lrint(Z)); 00059 G4double nucleusMass = Z*proton_mass_c2+(A-Z)*neutron_mass_c2+bindingEnergy; 00060 G4double reducedMass = mass*nucleusMass/(mass+nucleusMass); 00061 00062 G4double nucleonMass = (proton_mass_c2+neutron_mass_c2)/2; 00063 00064 // _factor in (MeV*fermi)*fermi/MeV = fermi*fermi -- need to have A as density normalized to 1 00065 theFactor = 2*pi*hbarc*hbarc*(1+mass/nucleonMass)* opticalParameter/reducedMass * A; 00066 00067 theMass = mass; 00068 } 00069 00070 00071 void G4KM_OpticalEqRhs::EvaluateRhsGivenB(const G4double y[], const G4double *, 00072 G4double dydx[]) const 00073 { 00074 G4double yMod = std::sqrt(y[0]*y[0]+y[1]*y[1]+y[2]*y[2]); 00075 G4double e = std::sqrt(theMass*theMass+y[3]*y[3]+y[4]*y[4]+y[5]*y[5]); 00076 dydx[0] = c_light*y[3]/e; // 00077 dydx[1] = c_light*y[4]/e; // dq/dt=dH/dp = c*p/e 00078 dydx[2] = c_light*y[5]/e; // 00079 00080 // V=K*rho(r) ==> dydx[3] = -dV/dr*dr/dx = -K*d(rho)/dr*dr/dx. 00081 // Idem for dydx[4] and dydx[5] 00082 00083 const G4VNuclearDensity * nuclearDensity=theNucleus->GetNuclearDensity(); 00084 00085 G4ThreeVector pos(y[0],y[1],y[2]); 00086 G4double deriv = theFactor*nuclearDensity->GetDeriv(pos); 00087 00088 dydx[3] = yMod == 0 ? 0 : -deriv*y[0]/yMod*c_light; 00089 dydx[4] = yMod == 0 ? 0 : -deriv*y[1]/yMod*c_light; 00090 dydx[5] = yMod == 0 ? 0 : -deriv*y[2]/yMod*c_light; 00091 } 00092 00093 00094 00095