Laser Wakefield Plasma Acceleration
Laser Wakefield Plasma Acceleration (LWPA) is a method of accelerating electrons that can achieve extremely high accelerating gradients by the interaction of a high power laser pulse with a plasma (1). This is an attractive technology because as the accelerating gradient is much higher than for conventional radio-frequency (RF) cavities it raises the possibility of much shorter accelerators for a given particle energy (2) which has driven an intense research effort over the past decade with many notable successes (3). The standard approach to LWPA is to use a single very intense laser pulse to excite the plasma oscillations which create the accelerating gradient. This requires complex and expensive laser systems to reach the required powers which can only be supported at specialist facilities, often at national labs.
We are pursuing a different method of exciting the plasma. Instead of having a single laser pulse, we are researching the use of a train of pulses spaced to resonantly enhance the plasma oscillation. This has been investigated in a number of theoretical papers (4i-iv) but not yet demonstrated experimentally. We plan to use our expertise in high power fibre lasers in collaboration with Simon Hooker's LWPA group in Oxford to test the theoretical predictions on resonant laser plasma enhancement and build a laser plasma accelerator based on this approach. Additionally, we are working in collaboration with Stuart Mangle's group at Imperial College London.