  The Centre for the Clinical Application of Particles' Laser-hybrid
Accelerator for Radiobiological Applications (LhARA) facility is being studied
and requires simulation of novel accelerator components (such as the Gabor lens
capture system), detector simulation and simulation of the ion beam interaction
with cells. The first stage of LhARA will provide protons up to 15 MeV for in
vitro studies. The second stage of LhARA will use a fixed-field accelerator to
increase the energy of the particles to allow in vivo studies with protons and
in vitro studies with heavier ions.
  BDSIM, a Geant4 based accelerator simulation tool, has been used to perform
particle tracking simulations to verify the beam optics design done by
BeamOptics and these show good agreement. Design parameters were defined based
on an EPOCH simulation of the laser source and a series of mono-energetic input
beams were generated from this by BDSIM. The tracking results show the large
angular spread of the input beam (0.2 rad) can be transported with a
transmission of almost 100% whilst keeping divergence at the end station very
low (<0.1 mrad). The legacy of LhARA will be the demonstration of technologies
that could drive a step-change in the provision of proton and light ion therapy
(i.e. a laser source coupled to a Gabor lens capture and a fixed-field
accelerator), and a system capable of delivering a comprehensive set of
experimental data that can be used to enhance the clinical application of
proton and light ion therapy.
