Generating coherent soft x-ray pulses in the water window with a high-brightness seeded free-electron laser

TL;DR

This paper introduces a novel seeded free-electron laser scheme combining coherent harmonic generation and superradiance to produce high-brightness, coherent soft x-ray pulses in the water window, with potential for 10 GW-level power.

Contribution

It presents a new method integrating CHG and superradiant principles in a seeded FEL to generate ultra-short, high-brightness soft x-ray pulses in the water window.

Findings

Achieved 10 GW-level coherent soft x-ray pulses in simulations.

Demonstrated effectiveness of combining CHG and superradiance.

Produced ultra-short pulses suitable for advanced imaging.

Abstract

We propose a new scheme to generate high-brightness and temporal coherent soft x-ray radiation in a seeded free-electron laser. The proposed scheme is based the coherent harmonic generation (CHG) and superradiant principles. A CHG scheme is first used to generate coherent signal at ultra-high harmonics of the seed. This coherent signal is then amplified by a series of chicane-undulator modules via the fresh bunch and superradiant processes in the following radiator. Using a representative of realistic set of parameters, three-dimensional simulations have been carried out and the simulations results demonstrated that 10 GW-level ultra-short coherent radiation pulses in the water window can be achieved by using the proposed technique.