Direct laser acceleration with structured light and controlled ionization

Intense lasers enable a range of schemes for generating high-energy particle beams in university-scale laboratories. In direct laser acceleration (DLA), the leading edge of the laser pulse ionizes the target material, forming a positively charged plasma channel that traps and accelerates electrons. DLA offers exceptional energy conversion efficiency - often exceeding 20% -making it highly suitable for driving secondary radiation sources. This talk reviews recent advances aimed at pushing the efficiency and applicability of DLA for compact radiation sources.

I will present experimental and numerical studies showing how DLA performance can be enhanced by tailoring the target’s atomic number to sustain electron injection, and by employing flying-focus pulses to mitigate nonlinear propagation effects, such as self-focusing and filamentation, which distort both the laser fields and the quasi-static fields of the ion channel.

Building on these developments, I will show how flying-focus pulses enable the formation of a stable, uniform ion channel over the entire acceleration length, resulting in higher electron energies and enhanced X-ray Betatron emission. Additionally, I will present how a bright Compton X-ray source can be realized using counter-propagating pulses interacting with a near-critical high-Z plasma plume.