Particle accelerators have become powerful and widely used tools for industry, medicine, and science. Today there are some 30,000 particle accelerators worldwide, all of them relying on long-proven and highly developed methods for increasing the energy of charged particles using radio-frequency (RF) technology. The maximum achievable accelerating gradient from RF technology is generally limited to 100 MV/m due to breakdown in the metallic cavities. There is substantial interest in a new type of accelerating technology based on exploiting the incredibly large electromagnetic fields formed in the wake of a high energy laser travelling through a plasma. A plasma has essentially no breakdown limit, allowing for accelerating gradients over a thousand times greater than those for RF structures to be achieved. Such technology has the possibility to revolutionise particle acceleration, allowing for high beam energies to be achieved on length scales as short as a centimetre (compared to several kilometres with RF technology). This technology could be applied readily throughout academia and industry and dramatically expand how particle accelerators are ultimately used.
The goal of the EuPRAXIA project is to produce a conceptual design report for a worldwide first high-energy plasma-based accelerator that can provide beam quality suitable for industrial use integrated with user exploitation areas. It is the important intermediate step between proof-of-principle experiments and ground-breaking, ultra-compact accelerators for science, industry, medicine or even particle physics at the energy frontier.
One of the possible applications of EuPRAXIA is as the driver for a free electron laser; ASTeC is applying our expertise in FELs to this design study to understand how the electron beams from EuPRAXIA can be matched to the needs of an FEL. This is not simple, as this new type of accelerator produces quite different beam parameters to conventional accelerators making it very challenging to then drive an FEL. We plan to use our test facility, CLARA, in collaboration with other EuPRAXIA partners, to gain a deeper understanding of the practical challenges involved and to try out some possible solutions. The design study is funded by the European Union and has sixteen partner institutes.