BDSFieldMagDetectorSolenoid.cc

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) Royal Holloway, 
University of London 2001 - 2024.
 
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 "BDSFieldMagDetectorSolenoid.hh"
 
#include "globals.hh" // geant4 types / globals
#include "G4ThreeVector.hh"
 
#include <cmath>
 
BDSFieldMagDetectorSolenoid::BDSFieldMagDetectorSolenoid(G4double BIn,
                                                         G4double BOut,
                                                         G4double radiusIn,
                                                         G4double radiusOut,
                                                         G4double zMin,
                                                         G4double zMax):
  itsBIn(BIn),
  itsBOut(BOut),
  itsRadiusIn(radiusIn),
  itsRadiusOut(radiusOut),
  itsZMin(zMin),
  itsZMax(zMax)
{;}
 
G4ThreeVector BDSFieldMagDetectorSolenoid::GetField(const G4ThreeVector &position,
                                                    const G4double       /*t*/) const
{
  G4ThreeVector result(0,0,0);
  G4double zField   = 0;
  G4double localRad = std::hypot(position.y(),position.x());
 
  if( (position.z() > itsZMin) && (position.z() < itsZMax) )
    {
      if(localRad<itsRadiusIn)
        {zField = itsBIn;}
      else if(localRad<itsRadiusOut)
        {zField = itsBOut;}
      else
        {zField=0;}
    }
  else
    {zField=0;}
 
  result[2] = zField;
  return result;
}