Hard x-ray or gamma ray laser by a dense electron beam

TL;DR

This paper proposes a method to generate coherent x-ray or gamma ray radiation using a dense electron beam and an intense laser undulator, analyzing the process with Landau damping theory to account for high energy spread.

Contribution

It introduces a new analysis approach for free electron lasers with high energy spread and predicts feasible gamma ray generation up to 100 keV with current technology.

Findings

Coherent gamma rays up to 100 keV are achievable.

Landau damping theory is more suitable than linear analysis for high energy spread.

Quantum diffraction effects limit maximum radiation energy.

Abstract

A coherent x-ray or gamma ray can be created from a dense electron beam propagating through an intense laser undulator. It is analyzed by using the Landau damping theory which suits better than the conventional linear analysis for the free electron laser, as the electron beam energy spread is high. The analysis suggests that the currently available physical parameters would enable the generation of the coherent gamma ray of up to 100 keV. The electron quantum diffraction suppresses the FEL action, by which the maximum radiation energy to be generated is limited.