Laser-Plasma Accelerators

Plasma accelerators utilize the enormous electric fields formed within plasma waves to accelerate charged particles to high energies in a fraction of the distance needed in a conventional particle accelerator. We study this rapidly evolving area experimentally and via analytic and numerical theory.

Our lead academics are all members of the John Adams Institute (JAI), working in Oxford's sub-departments of Particle Physics and in Atomic & Laser Physics. We collaborate closely with JAI at Imperial College and with groups at DESY, Jena, MPQ and LBNL.

On this page you will find links to our Experiment and Theory programmes. If you are interested in joining us as a graduate student or post-doc, please see our Recruitment page.

Plasma bubble: Numerical simulation of a highly nonlinear plasma wave driven by an intense laser pulseWhen an intense laser pulse propagates through a plasma, the ponderomotive force pushes electrons away from the front and back of the pulse thereby forming a trailing longitudinal density wave. The longitudinal electric field in the plasma wave can be as high as 100 GV m-1, more than three orders of magnitude larger than that found in conventional RF accelerators such as those used at CERN. Particles injected into the correct phase of the plasma wave can be accelerated to energies of order 1 GeV in only a few tens of millimetres. This 'laser wakefield accelerator' is particularly promising for generating beams of short pulse, high-energy electrons for applications in femtosecond electron diffraction, medical imaging, and miniature free-electron X-ray lasers.

The successful implementation of laser-driven accelerators requires the driving laser pulse to be guided over tens of millimetres. One way of achieving this is to use a 'plasma channel' such as the capillary discharge waveguide developed by our group. In collaboration with Lawrence Berkeley National Laboratory we have used this approach to generate electron beams with energies of 1 GeV — an energy comparable to that used in today's synchrotron machines - in an acceleration stage only 30 mm long.

We are now developing techniques for increasing the shot-to-shot stability and energy of laser accelerated electron beams. We are also exploring the applications of laser-accelerated electron beams, in particular the exciting prospect of a new generation of very compact sources of ultrafast x-ray pulses. Our work in this area has been supported by a Leverhulme International Network as well as by EPSRC.

Further reading

  1. S. M. Hooker, R. Bartolini, S. P. D. Mangles, A. Tünnermann, L. Corner, J. Limpert, A. Seryi, & R. Walczak, "Multi-Pulse Laser Wakefield Acceleration: A New Route to Efficient, High-Repetition-Rate Plasma Accelerators and High Flux Radiation Sources," J. Phys. B 47 234003 (2014)
  2. S. M. Hooker, "Developments in laser-driven plasma accelerators," Nature Photonics 7 775–782 (2013)
  3. W. P. Leemans, S. M. Hooker et al., "GeV electron beams from a centimetre-scale accelerator," Nature Physics 2 696 (2006).
  4. J. Osterhoff, S. Karsch, S. M. Hooker et al., "Generation of Stable, Low-Divergence Electron Beams by Laser-Wakefield Acceleration in a Steady-State-Flow Gas Cell," Phys. Rev. Lett. 101 085002 (2008).
  5. T.P. Rowlands-Rees, S. M. Hooker et al., "Laser-Driven Acceleration of Electrons in a Partially Ionized Plasma Channel," Phys. Rev. Lett. 100 105005 (2008).
  6. M. Fuchs, F. Gruner, S. Karsch, S. M. Hooker et al., "Laser-driven soft-X-ray undulator source," Nature Physics 5 826 (2009).
  7. T. Ibbotson, S. M. Hooker et al., "Laser-wakefield acceleration of electron beams in a low density plasma channel," Phys. Rev. ST Acc. Beams 13 031301 (2010)