BDSMagUsualEqRhs.cc

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) Royal Holloway, 
University of London 2001 - 2023.
 
This file is part of BDSIM.
 
BDSIM is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published 
by the Free Software Foundation version 3 of the License.
 
BDSIM is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with BDSIM.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "BDSGlobalConstants.hh"
#include "BDSMagUsualEqRhs.hh"
#include "BDSStep.hh"
#include "G4Mag_EqRhs.hh"
 
#include "globals.hh" // geant4 types / globals
#include "G4ClassicalRK4.hh"
#include "G4ChargeState.hh"
#include "G4MagneticField.hh"
#include "G4SystemOfUnits.hh"
#include "G4PhysicalConstants.hh"
#include "BDSGlobalConstants.hh"
 
BDSMagUsualEqRhs::BDSMagUsualEqRhs(G4MagneticField* MagField):
  G4Mag_UsualEqRhs(MagField),
  fMassCof(0.),
  fCof_val(0.)
{;}
 
void BDSMagUsualEqRhs::SetChargeMomentumMass( G4ChargeState particleCharge,
                                              G4double MomentumXc,
                                              G4double particleMass)
{
  G4Mag_EqRhs::SetChargeMomentumMass(particleCharge, MomentumXc, particleMass);
  G4double pcharge = particleCharge.GetCharge();
 
  fCof_val = pcharge*eplus*c_light ; //  B must be in Tesla
  fMassCof = particleMass*particleMass;
}
 
G4double BDSMagUsualEqRhs::Beta(const G4double y[6])
{
  G4ThreeVector mom = G4ThreeVector(y[3], y[4], y[5]);
  G4double beta = Beta(mom);
  return beta;
}
 
G4double BDSMagUsualEqRhs::Beta(const G4ThreeVector& mom)
{
  G4double momentum_mag_square = mom.mag2();
  G4double Energy = std::sqrt(momentum_mag_square + fMassCof);
  G4double beta   = std::sqrt(momentum_mag_square) / Energy;
  return beta;
}
 
G4double BDSMagUsualEqRhs::TotalEnergy(const G4double y[])
{
  G4ThreeVector mom = G4ThreeVector(y[3], y[4], y[5]);
  G4double Energy = TotalEnergy(mom);
  return Energy;
}
 
G4double BDSMagUsualEqRhs::TotalEnergy(const G4ThreeVector& mom)
{
  G4double momentum_mag_square = mom.mag2();
  G4double Energy = std::sqrt(momentum_mag_square + fMassCof);
  return Energy;
}