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_NucleonEqRhs.cc 00033 // 00034 // Author: Alessandro Brunengo (Alessandro.Brunengo@ge.infn.it) 00035 // 00036 // Creation date: 5 June 2000 00037 // ------------------------------------------------------------------- 00038 00039 #include "G4KM_NucleonEqRhs.hh" 00040 #include "G4VNuclearDensity.hh" 00041 00042 #include "G4PhysicalConstants.hh" 00043 00044 G4KM_NucleonEqRhs::G4KM_NucleonEqRhs(G4KM_DummyField *field, 00045 G4V3DNucleus * nucleus) : 00046 G4Mag_EqRhs(field), theNucleus(nucleus) 00047 { 00048 theMass = 0.; 00049 A = theNucleus->GetMassNumber(); 00050 factor = hbarc*hbarc*std::pow(3.*pi2*A,2./3.)/3.; 00051 } 00052 00053 00054 void G4KM_NucleonEqRhs::EvaluateRhsGivenB(const G4double y[], 00055 const G4double *, 00056 G4double dydx[]) const 00057 { 00058 G4double yMod = std::sqrt(y[0]*y[0]+y[1]*y[1]+y[2]*y[2]); 00059 G4double e = std::sqrt(theMass*theMass+y[3]*y[3]+y[4]*y[4]+y[5]*y[5]); 00060 00061 // y[0..2] is position 00062 // y[3..5] is momentum (and not mom.direction) 00063 00064 dydx[0] = c_light*y[3]/e; // 00065 dydx[1] = c_light*y[4]/e; // dq/dt=dH/dp = c*p/e 00066 dydx[2] = c_light*y[5]/e; // 00067 00068 /* 00069 * // debug 00070 * G4cout << " Nucleon RHS : 0..2(dpos/dt) " << 00071 * dydx[0] << " " << 00072 * dydx[1] << " " << 00073 * dydx[2] << " " << G4endl; 00074 */ 00075 00076 00077 // V=K*rho(r) ==> dydx[3] = -dV/dr*dr/dx = -K*d(rho)/dr*dr/dx. 00078 // GF should be V=K*rho(r) ==> dydx[3] = -dV/dr*dr/dx = -K*d(rho)/dr*dr/dt 00079 // GF and dV/dt = dE/dt ==> dp/dt = dE/dt * dp/dE = dE/dt *e/p 00080 // Idem for dydx[4] and dydx[5] 00081 00082 G4ThreeVector pos(y[0],y[1],y[2]); 00083 00084 const G4VNuclearDensity * nuclearDensity=theNucleus->GetNuclearDensity(); 00085 00086 // do not check for theMass != 0 : it is an error and core dump will signal it 00087 00088 G4double density= nuclearDensity->GetDensity(pos); 00089 G4double deriv(0); 00090 if (density > 0 ) deriv = (factor/theMass)* 00091 std::pow(density, -1./3.)*nuclearDensity->GetDeriv(pos); 00092 00093 // dydx[3] = yMod == 0 ? 0 : -deriv*y[0]/yMod; 00094 // dydx[4] = yMod == 0 ? 0 : -deriv*y[1]/yMod; 00095 // dydx[5] = yMod == 0 ? 0 : -deriv*y[2]/yMod; 00096 dydx[3] = yMod == 0 ? 0 : deriv*y[0]/yMod*c_light; 00097 dydx[4] = yMod == 0 ? 0 : deriv*y[1]/yMod*c_light; 00098 dydx[5] = yMod == 0 ? 0 : deriv*y[2]/yMod*c_light; 00099 00100 00101 /* 00102 * // debug 00103 * G4cout << " Nucleon RHS : 3..5(dE/dt) " << 00104 * dydx[3] << " " << 00105 * dydx[4] << " " << 00106 * dydx[5] << " " << G4endl; 00107 */ 00108 } 00109 00110 00111 00112