Atomic inner-shell radiation seeded free-electron lasers

TL;DR

This paper proposes a novel scheme for X-ray free-electron lasers (XFELs) seeded by atomic inner-shell lasers, aiming to enhance output quality and coherence for shorter wavelengths.

Contribution

It introduces a theoretical scheme using atomic inner-shell lasers as seeds to improve XFEL coherence and stability, extending potential applications to shorter wavelengths.

Findings

Atomic inner-shell lasers can effectively seed XFELs.

Seeding with inner-shell lasers improves temporal coherence.

The scheme shows promise for generating shorter wavelength XFEL pulses.

Abstract

In order to effectively improve the output quality of X-ray free electron laser (XFEL), we theoretically propose an XFEL scheme seeded by atomic inner-shell laser. As well known, an atomic inner-shell laser based on neutral atoms and pumped by an XFEL has been experimentally demonstrated, which produced sub-femtosecond X-ray pulses with increased temporal coherence. It shows that, by using the inner-shell laser as a seed to modulate the electron bunch, very stable and almost fully-coherent short-wavelength XFEL pulses can be generated. The proposed scheme holds promising prospects in X-ray wavelengths, and even shorter.