Generation of stable ultra-relativistic attosecond electron bunches via the laser wakefield acceleration mechanism

TL;DR

This paper predicts the generation of stable, ultra-relativistic attosecond electron bunches using laser wakefield acceleration, supported by theoretical calculations and spectral evidence from betatron radiation.

Contribution

It introduces a novel prediction that LWFA can produce stable attosecond electron bunches due to betatron phase mixing, expanding the understanding of electron bunch durations achievable.

Findings

Attosecond bunches can be generated by LWFA.

These bunches are stable outside the accelerator and propagate in vacuum.

Spectral features of betatron radiation indicate attosecond bunch formation.

Abstract

In recent experiments ultra-relativistic femtosecond electron bunches were generated by a Laser Wakefield Accelerator (LWFA) in different regimes. Here we predict that even attosecond bunches can be generated by an LWFA due to the fast betatron phase mixing within a femtosecond electron bunch. The attosecond bunches are stable outside the LWFA and can propagate in vacuum many tens of centimeter without significant change in their duration. Our calculations show that evidence for the formation of attosecond bunches can be found in the spectrum of coherent betatron radiation from LWFA's.