Quasi-monoenergetic electron beams production in a sharp density transition

TL;DR

This paper demonstrates a method to produce quasi-monoenergetic electron beams exceeding 0.4 GeV using a laser plasma accelerator with a sharp density transition created by a crossing pre-pulse, enabling improved control over electron beam parameters.

Contribution

It introduces a novel technique of using a crossing pre-pulse to generate a sharp density ramp for enhanced monoenergetic electron beam production in laser wakefield acceleration.

Findings

Achieved electron energies over 0.4 GeV.

More than 40% of shots produced quasi-monoenergetic spectra.

Controlled the electron beam parameters by adjusting pre-pulse position.

Abstract

Using a laser plasma accelerator, experiments with a 80 TW and 30 fs laser pulse demonstrated quasi-monoenergetic electron spectra with maximum energy over 0.4 GeV. This is achieved using a supersonic He gas jet and a sharp density ramp generated by a high intensity laser crossing pre-pulse focused 3 ns before the main laser pulse. By adjusting this crossing pre-pulse position inside the gas jet, among the laser shots with electron injection more than 40% can produce quasi-monoenergetic spectra. This could become a relatively straight forward technique to control laser wakefield electron beams parameters.