07 Dec 2020



LhARA - The Laser-hybrid Accelerator for Radiobiological Application


Co-supervisors: PPD - J. Matheson, Imperial College London - Prof K. Long

PPD is working with the Centre for the Clinical Application of Particles (CCAP) and the John Adams Institute (JAI) at Imperial College, on the development of the Laser-hybrid Accelerator for Radiobiological Applications (LhARA).

There is currently worldwide interest in the use of charged particle beams for the treatment of cancer. In principle, the energy deposition from charged particles can be controlled much more accurately than that from the more commonly used photon beams, sparing healthy tissue and leading to improved patient outcomes. However, the understanding of the dosimetry of charged particle beams currently lags the development of beam delivery facilities.

LhARA is being designed as a facility for the systematic study of radiobiology, with future applications to particle-beam radiotherapy, including “flash” radiotherapy at ultra-high dose rates. Further, LhARA is intended to revolutionise the design of radiotherapy facilities themselves, with a novel two stage proton/ion beam delivery system. The first stage involves a pulsed laser incident on a target, with the emitted particles being captured by a novel plasma lens (Gabor lens). This first stage provides in itself a facility suitable for use in studying the radiobiology of cell cultures. In the second stage, the low energy beam from the first stage is accelerated using a fixed-field, alternating gradient accelerator (FFA), to energies suitable for small-animal radiobiology studies.

We seek a student to work on the development of instrumentation for the LhARA beamline itself and also for the experimental end stations. Measurements of the beam profile, energy and intensity are needed for both end stations. Novel techniques such as proton- or ion-acoustic imaging will be investigated. The low energy beamline is particularly challenging, needing very low mass or non-intercepting measurements. The proposed FFA requires the development of beam position monitoring and tune measurement. The techniques developed will be synergistic with the upgrade of the ISIS spallation neutron source at RAL and with the accelerator driven reactor (“energy amplifier”) at the KURNS laboratory in Kyoto. The ultimate goal of the instrumentation development for LhARA is to measure beam parameters in real time, in such a way that the accelerator chain is continually tuned to deliver the desired dose, over the required area and at the correct tissue depth.

Possible work as part of the project could involve the development of beam monitors for the FFA in collaboration with CERN, novel diagnostics and dose-measurement systems, instrumentation for the novel electron-plasma “Gabor” lens, and a prototype instrumented water phantom. Simulations of beam interactions in tissue will eventually be needed, as part of designing a suite of instrumentation capable of locating the Bragg peak in real time. We work in international collaborations and the successful application will have the opportunity to work at CERN, in Paris, or Vienna.

The student will join a young collaboration, with a real opportunity to play an important role in its development and to influence the direction of the research.

Contact: Long, Ken (Oxford Uni.,RAL,PPD)