/scratch0/jsnuveri/BDSIM/BDSIMgit/bdsim/src/BDSOctupole.cc

/* BDSIM code.    Version 1.0
   Author: Grahame A. Blair, Royal Holloway, Univ. of London.
   Last modified 24.7.2002
   Copyright (c) 2002 by G.A.Blair.  ALL RIGHTS RESERVED. 

   Modified 22.03.05 by J.C.Carter, Royal Holloway, Univ. of London.
   Changed StringFromInt to be the BDSGlobal version
*/

#include "BDSBeamPipeInfo.hh"
#include "BDSGlobalConstants.hh" 
#include "BDSMagnet.hh"
#include "BDSMagnetOuterInfo.hh"
#include "BDSMagnetType.hh"
#include "BDSOctupole.hh"
#include "BDSOctMagField.hh"
#include "BDSOctStepper.hh"

#include "G4FieldManager.hh"
#include "G4LogicalVolume.hh"
#include "G4Tubs.hh"
#include "G4UserLimits.hh"
#include "G4VisAttributes.hh"
#include "G4VPhysicalVolume.hh"

class BDSTiltOffset;

BDSOctupole::BDSOctupole(G4String           name,
                         G4double           length,
                         G4double           bTriplePrime,
                         BDSBeamPipeInfo*   beamPipeInfo,
                         BDSMagnetOuterInfo magnetOuterInfo,
                         BDSTiltOffset      tiltOffset):
  BDSMagnet(BDSMagnetType::octupole, name, length,
            beamPipeInfo, magnetOuterInfo, tiltOffset),
  itsBTriplePrime(bTriplePrime)
{;}

void BDSOctupole::Build() {
  BDSMagnet::Build();
  if(BDSGlobalConstants::Instance()->GetIncludeIronMagFields())
    {
      G4double polePos[4];
      G4double Bfield[3];
      
      //coordinate in GetFieldValue
      polePos[0]=-BDSGlobalConstants::Instance()->GetMagnetPoleRadius()*sin(CLHEP::pi/8);
      polePos[1]=BDSGlobalConstants::Instance()->GetMagnetPoleRadius()*cos(CLHEP::pi/8);
      polePos[2]=0.;
      polePos[3]=-999.;//flag to use polePos rather than local track
      
      itsMagField->GetFieldValue(polePos,Bfield);
      G4double BFldIron=
        sqrt(Bfield[0]*Bfield[0]+Bfield[1]*Bfield[1])*
        BDSGlobalConstants::Instance()->GetMagnetPoleSize()/
        (BDSGlobalConstants::Instance()->GetComponentBoxSize()/2-
         BDSGlobalConstants::Instance()->GetMagnetPoleRadius());
      
      // Magnetic flux from a pole is divided in two directions
      BFldIron/=2.;
      
      BuildOuterFieldManager(8, BFldIron,CLHEP::pi/8);
    }
}

void BDSOctupole::BuildBPFieldAndStepper()
{
  // set up the magnetic field and stepper
  itsMagField=new BDSOctMagField(itsBTriplePrime);
  itsEqRhs=new G4Mag_UsualEqRhs(itsMagField);
  
  BDSOctStepper* octStepper=new BDSOctStepper(itsEqRhs);
  octStepper->SetBTrpPrime(itsBTriplePrime);
  itsStepper = octStepper;
}

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