Multi-MeV electron acceleration by sub-terawatt laser pulses

TL;DR

This paper reports the successful acceleration of high-charge electron beams to around 10 MeV using ultra-short, low-energy laser pulses in a dense hydrogen gas jet, enabling portable laser-driven applications.

Contribution

It demonstrates high-charge electron acceleration with sub-terawatt laser pulses in a dense gas jet, a significant advancement in laser-plasma acceleration technology.

Findings

Achieved ~10 MeV electron energies with only 10 mJ laser pulses.

Measured up to ~0.5 nC charge for electrons above 1 MeV.

Observed wavebreaking and broadband light emission correlated with acceleration.

Abstract

We demonstrate laser-plasma acceleration of high charge electron beams to the ~10 MeV scale using ultrashort laser pulses with as little energy as 10 mJ. This result is made possible by an extremely dense and thin hydrogen gas jet. Total charge up to ~0.5 nC is measured for energies >1 MeV. Acceleration is correlated to the presence of a relativistically self-focused laser filament accompanied by an intense coherent broadband light flash, associated with wavebreaking, which can radiate more than ~3% of the laser energy in a sub-femtosecond bandwidth consistent with half-cycle optical emission. Our results enable truly portable applications of laser-driven acceleration, such as low dose radiography, ultrafast probing of matter, and isotope production.