Progress towards high-repetition-rate laser-plasma accelerators
by
R61 CR03 (RAL)
In a laser-plasma accelerator (LPA) the ponderomotive force of a short (~ 50 fs), intense (~1018 W / cm2) laser pulse drives a trailing plasma wave. The spatial variation of the electron density within this wave generates electric fields of order 100 GV / m, around three orders of magnitude larger than those used in conventional, radio-frequency accelerators. This electric field structure, the plasma wakefield, propagates at the speed of the laser, and hence can be used to accelerate particles to relativistic energies.
Laser-plasma accelerators have generated electron bunches with energies as high as ~ 10 GeV, in accelerator stages only a few centimetres long. Their compact size, and the desirable properties of the bunches they generate – such as low emittance and femtosecond duration – would seem to make laser-driven accelerators ideally suited to applications such as driving compact light sources or enabling experiments in novel high-field science.
However, many of these applications would require the LPA to operate at pulse repetition rates substantially higher than the few pulses per second typically achieved today. In this seminar I will briefly review the operation of laser-plasma accelerators and the state of the field, before discussing recent work by my group aimed at enabling GeV-scale LPAs to operate at kilohertz repetition rates: (i) the development of hydrodynamic optical-field-ionized (HOFI) plasma channels, and (ii) plasma-modulated plasma accelerators (P-MoPAs).
Biography
Following his undergraduate degree, Simon Hooker remained in Oxford for his doctoral research on short-wavelength lasers, under the supervision of Prof. Colin Webb FRS. In 1994 he moved to Stanford University to work on optical field ionization lasers with Prof. Steve Harris. He returned to Oxford in 1996 as a Royal Society University Research Fellow, and in 2003 was appointed to a University Lectureship and to a Tutorial Fellowship at Merton College Oxford. He was Head of the sub-department of Atomic & Laser Physics between 2019 and 2024.
Simon’s group in Oxford has worked on a range of topics, including extreme ultraviolet lasers, high-intensity waveguides, and most recently laser-driven plasma accelerators. To date Simon has supervised 26 DPhil students to completion of their theses.
Simon is a regular user of the high-power laser facilities at RAL, primarily the Astra-Gemini laser, but he has also undertaken experiments in Athens, Berkeley, Paris, and Munich, as well as at CERN.
Simon is a Fellow of Optica (formerly the Optical Society of America) and of the UK’s Institute of Physics. In 2010 he was awarded the APS John Dawson Prize for Excellence in Plasma Physics and the 2020 the IOP’s Cecilia Payne-Gaposchkin Medal and Prize.