Novel Techniques for control and optimisation of laser driven ion beams

Key to the interest in a laser based particle accelerator lies in its cost effective and compactness. However, the proton beams accelerated by one of the highly promising laser based acceleration mechanisms, the so called Target Normal Sheath Acceleration (TNSA), suffers of shortcomings such as a broad energy spectrum and large beam divergence. The project aims to unlock the full potential of a number of novel techniques in order to control and improve upon the proton beam parameters, and possibly to deliver a beam of accelerator standard for widespread application in science, industry and healthcare. The techniques are based on either simple modifications of target shape and geometry, or by ingeniously harnessing extremely high electrostatic and magnetic fields produced by the interaction of intense lasers. A specific interest is that, by utilising these techniques, lasers can be transported close to the application area circumventing delivery beam-lines and radiation shielding costs associated with a conventional machine.

A collimated dense bunch of energetic ions is highly attractive in view of the development of an appealing neutron source. Given the fact that the ions are produced by a compact laser-based machine, the neutron souce will offer opportunities for industrial, technological and healthcare applications, such as diagnosis of Li-ion battery and fuel cells, semiconductor doping and cancer therapy centre based on novel Boron neutron capture therapy (BNCT) technique. Over the two year duration of the grant, a rigorous work plan will be implemented. Whereas the in-house laser facility (TARANIS) at the host university will facilitate a systematic investigation of several aspects of the schemes, the schemes will be fielded at large-scale, laser facilities with significantly higher power (such as the Vulcan and GEMINI Petawatt facilities at RAL-STFC, UK) with the aim to demonstrate the expected improved performance.

Although the full impact of this work will be realised on timescales longer than the grant duration, there will be output and consequence of its work which will have impact and relevance at several levels and over different timescales.

The work on enabling control and optimisation of the laser driven proton beams will provide a cost-effective and compact alternative to conventional accelerators, which will lay a pathway towards a major societal impact by informing a strategic roadmap towards next generation of affordable cancer treatment facilities. Although the long term healthcare application will clearly have huge investment leverage, other sectors such as industry (eg. lithography, implantation), science (eg. fusion research) and security (eg. Remote threat detection using secondary radiation sources, eg. neutrons) will be highly benefited by the development of a laser based ion source. A medium term impact of the work in Science would be towards warm dense matter studies, which are highly relevant for fusion research - the quest to overcome present energy challenges.

Creating new avenues of research implies creating new opportunities for training 'fresh blood' and recruiting scientists, creating new laboratory facilities. This can be seen as a critical pathway to social and economic impact as it lays the basis of continuous supply of well-trained and qualified personnel with a range of options for career in academia, R&D, industry and other sectors, such as finance. At national level, efficient use of the laboratory facilities at the host organisation as well as in the STFC laser facilities will be made by providing well trained personnel during this project. The proposed research will complement the activities of the plasma physics group of the host university and will facilitate establishing an increasingly more visible 'centre of excellence' status. This can be seen as a direct impact on the university which will enhance further the recruitment prospects, particularly with respect to attracting Ph.D. students from outside Northern Ireland and overseas.