Gabriele Cosmo
93 lines
3.5 KiB
C++
93 lines
3.5 KiB
C++
//
|
|
// ********************************************************************
|
|
// * DISCLAIMER *
|
|
// * *
|
|
// * The following disclaimer summarizes all the specific disclaimers *
|
|
// * of contributors to this software. The specific disclaimers,which *
|
|
// * govern, are listed with their locations in: *
|
|
// * http://cern.ch/geant4/license *
|
|
// * *
|
|
// * Neither the authors of this software system, nor their employing *
|
|
// * institutes,nor the agencies providing financial support for this *
|
|
// * work make any representation or warranty, express or implied, *
|
|
// * regarding this software system or assume any liability for its *
|
|
// * use. *
|
|
// * *
|
|
// * This code implementation is the intellectual property of the *
|
|
// * GEANT4 collaboration. *
|
|
// * By copying, distributing or modifying the Program (or any work *
|
|
// * based on the Program) you indicate your acceptance of this *
|
|
// * statement, and all its terms. *
|
|
// ********************************************************************
|
|
//
|
|
//
|
|
// -------------------------------------------------------------------
|
|
// GEANT 4 class implementation file
|
|
//
|
|
// CERN, Geneva, Switzerland
|
|
//
|
|
// File name: G4KM_OpticalEqRhs.cc
|
|
//
|
|
// Author: Alessandro Brunengo (Alessandro.Brunengo@ge.infn.it)
|
|
//
|
|
// Creation date: 5 June 2000
|
|
// -------------------------------------------------------------------
|
|
|
|
#include "G4KM_OpticalEqRhs.hh"
|
|
#include "G4NucleiPropertiesTable.hh"
|
|
#include "G4VNuclearDensity.hh"
|
|
#include "G4HadTmpUtil.hh"
|
|
|
|
|
|
G4KM_OpticalEqRhs::G4KM_OpticalEqRhs(G4KM_DummyField *field,
|
|
G4V3DNucleus * nucleus) :
|
|
G4Mag_EqRhs(field), theNucleus(nucleus)
|
|
{
|
|
theFactor = 0;
|
|
theMass = 0;
|
|
}
|
|
|
|
|
|
void G4KM_OpticalEqRhs::SetFactor(G4double mass, G4double opticalParameter)
|
|
{
|
|
G4double A = theNucleus->GetMassNumber();
|
|
G4double Z = theNucleus->GetCharge();
|
|
G4double bindingEnergy = G4NucleiPropertiesTable::GetBindingEnergy(G4lrint(Z), G4lrint(A));
|
|
G4double nucleusMass = Z*proton_mass_c2+(A-Z)*neutron_mass_c2+bindingEnergy;
|
|
G4double reducedMass = mass*nucleusMass/(mass+nucleusMass);
|
|
|
|
G4double nucleonMass = (proton_mass_c2+neutron_mass_c2)/2;
|
|
|
|
// _factor in (MeV*fermi)*fermi/MeV = fermi*fermi -- need to have A as density normalized to 1
|
|
theFactor = 2*pi*hbarc*hbarc*(1+mass/nucleonMass)* opticalParameter/reducedMass * A;
|
|
|
|
theMass = mass;
|
|
}
|
|
|
|
|
|
void G4KM_OpticalEqRhs::EvaluateRhsGivenB(const G4double y[], const G4double *,
|
|
G4double dydx[]) const
|
|
{
|
|
G4double yMod = sqrt(y[0]*y[0]+y[1]*y[1]+y[2]*y[2]);
|
|
G4double e = sqrt(theMass*theMass+y[3]*y[3]+y[4]*y[4]+y[5]*y[5]);
|
|
dydx[0] = c_light*y[3]/e; //
|
|
dydx[1] = c_light*y[4]/e; // dq/dt=dH/dp = c*p/e
|
|
dydx[2] = c_light*y[5]/e; //
|
|
|
|
// V=K*rho(r) ==> dydx[3] = -dV/dr*dr/dx = -K*d(rho)/dr*dr/dx.
|
|
// Idem for dydx[4] and dydx[5]
|
|
|
|
const G4VNuclearDensity * nuclearDensity=theNucleus->GetNuclearDensity();
|
|
|
|
G4ThreeVector pos(y[0],y[1],y[2]);
|
|
G4double deriv = theFactor*nuclearDensity->GetDeriv(pos);
|
|
|
|
dydx[3] = yMod == 0 ? 0 : -deriv*y[0]/yMod*c_light;
|
|
dydx[4] = yMod == 0 ? 0 : -deriv*y[1]/yMod*c_light;
|
|
dydx[5] = yMod == 0 ? 0 : -deriv*y[2]/yMod*c_light;
|
|
}
|
|
|
|
|
|
|
|
|