Compensating the electron beam energy spread by the natural transverse gradient of laser undulator in all-optical x-ray light sources

TL;DR

This paper proposes a method to compensate for the large energy spread in laser-plasma accelerated electron beams using the natural transverse gradient of a laser undulator, enhancing the brightness of all-optical x-ray sources.

Contribution

It introduces a novel approach to mitigate electron beam energy spread effects by leveraging the natural transverse gradient of laser undulators, supported by theoretical and simulation analysis.

Findings

Effective compensation of energy spread demonstrated in simulations.

Potential for higher brightness in all-optical x-ray sources.

Applicable to both laser-Compton and free-electron laser setups.

Abstract

All-optical ideas provide a potential to dramatically cut off the size and cost of x-ray light sources to the university-laboratory scale, with the combination of the laser-plasma accelerator and the laser undulator. However, the large longitudinal energy spread of the electron beam from laser-plasma accelerator may hinder the way to high brightness of these all-optical light sources. In this paper, the beam energy spread effect is proposed to be significantly compensated by the natural transverse gradient of a laser undulator when properly transverse-dispersing the electron beam. Theoretical analysis and numerical simulations on conventional laser-Compton scattering sources and high-gain all-optical x-ray free-electron lasers with the electron beams from laser-plasma accelerators are presented.