Nanometer-scale pre-bunched electron beams generated from all-optical plasma-based acceleration

TL;DR

This paper proposes an all-optical plasma-based method to generate nanometer-scale pre-bunched electron beams, enabling the production of coherent, high-brightness x-rays for advanced light source applications.

Contribution

It introduces a novel scheme using counter-propagating lasers to modulate plasma wake phase velocity, achieving controlled electron micro-bunching at nanometer scales.

Findings

Demonstrates control over electron pre-bunching structures.

Shows potential for generating ultra-bright, coherent x-rays.

Proposes a compact, all-optical acceleration scheme.

Abstract

High-quality and prebunched electron beams can produce coherent x-rays with high intensity and narrow bandwidth, which is essential for modern light sources. An all-optical scheme based on plasma-based acceleration to produce bright electron beams that are pre-bunched on nanometer-scales is proposed. By using a density modulation created by two low intensity counter-propagating lasers, the phase velocity of the plasma wake excited by an intense driver laser in a uniform plasma can be modulated at a frequency twice that of the colliding lasers and thus turn the injection on and off. The injected electrons are micro-bunched at the Doppler shifted wavelength of the modulated wavelength using the corresponding phase velocity of the gradual expansion of the wakefield. It is demonstrated that by controlling the properties of the drive and colliding lasers, that beams with exotic pre-bunched structures can be produced, which may have critical applications in ultrafast high power x-rays. This extremely compact, all-optical scheme to produce ultra-bright pre-bunched electron beams may therefore enable novel applications for ultrafast x-ray users and arouse general interest in various fields.