BDSBunchBox.cc

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) Royal Holloway, 
University of London 2001 - 2022.
 
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 "BDSBunchBox.hh"
#include "BDSDebug.hh"
#include "BDSException.hh"
#include "BDSParticleCoordsFull.hh"
 
#include "parser/beam.h"
 
#include "Randomize.hh"
#include "CLHEP/Units/PhysicalConstants.h"
 
BDSBunchBox::BDSBunchBox():
  BDSBunch("box"),
  envelopeX(0.0),
  envelopeY(0.0),
  envelopeZ(0.0),
  envelopeXp(0.0),
  envelopeYp(0.0),
  envelopeZp(0.0),
  envelopeT(0.0),
  envelopeE(0.0)
{
  flatGen = new CLHEP::RandFlat(*CLHEP::HepRandom::getTheEngine());
}
 
BDSBunchBox::~BDSBunchBox()
{
  delete flatGen;
}
 
void BDSBunchBox::SetOptions(const BDSParticleDefinition* beamParticle,
                             const GMAD::Beam& beam,
                             const BDSBunchType& distrType,
                             G4Transform3D beamlineTransformIn,
                             const G4double beamlineSIn)
{
  BDSBunch::SetOptions(beamParticle, beam, distrType, beamlineTransformIn, beamlineSIn);
  envelopeX  = beam.envelopeX  * CLHEP::m;
  envelopeY  = beam.envelopeY  * CLHEP::m;
  envelopeZ  = beam.envelopeY  * CLHEP::m;
  envelopeXp = beam.envelopeXp * CLHEP::rad;
  envelopeYp = beam.envelopeYp * CLHEP::rad;
  envelopeZp = beam.envelopeYp * CLHEP::rad;
  envelopeT  = beam.envelopeT  * CLHEP::s;
  envelopeE  = beam.envelopeE  * CLHEP::GeV;
}
 
void BDSBunchBox::CheckParameters()
{
  BDSBunch::CheckParameters();
  if (envelopeX <  0)
    {throw BDSException(__METHOD_NAME__, "envelopeX < 0");}
  if (envelopeXp < 0)
    {throw BDSException(__METHOD_NAME__, "envelopeXp < 0");}
  if (envelopeY <  0)
    {throw BDSException(__METHOD_NAME__, "envelopeY < 0");}
  if (envelopeYp < 0)
    {throw BDSException(__METHOD_NAME__, "envelopeYp < 0");}
  if (envelopeZ <  0)
    {throw BDSException(__METHOD_NAME__, "envelopeZ < 0");}
  if (envelopeZp < 0)
    {throw BDSException(__METHOD_NAME__, "envelopeZp < 0");}
  if (envelopeT < 0)
    {throw BDSException(__METHOD_NAME__, "envelopeT < 0");}
  if (envelopeE < 0)
    {throw BDSException(__METHOD_NAME__, "envelopeE < 0");}
}
 
BDSParticleCoordsFull BDSBunchBox::GetNextParticleLocal()
{
  G4double x  = X0  + envelopeX  * (1-2*flatGen->shoot());
  G4double y  = Y0  + envelopeY  * (1-2*flatGen->shoot());
  G4double z  = Z0  + envelopeZ  * (1-2*flatGen->shoot());
  G4double xp = envelopeXp * (1-2*flatGen->shoot());
  G4double yp = envelopeYp * (1-2*flatGen->shoot());
  G4double zp = envelopeZp * (1-2*flatGen->shoot());
  G4ThreeVector dir(xp,yp,zp);
  dir = dir.unit();
  xp = dir.x();
  yp = dir.y();
  zp = dir.z();
  
  G4double t  = T0 + envelopeT * (1.- 2.*flatGen->shoot());
  G4double E  = E0 + envelopeE * (1 - 2.*flatGen->shoot());
  
  return BDSParticleCoordsFull(x,y,z,xp,yp,zp,t,S0+z,E,/*weight=*/1.0);
}