Influence of the electron beam emittance on the polarization of a laser--electron X-ray generator

TL;DR

This paper investigates how the finite emittance of electron beams in laser-electron X-ray generators affects the polarization of emitted X-ray radiation, revealing depolarization effects and potential applications.

Contribution

It provides analytical relations linking polarization states to beam parameters and demonstrates the impact of electron beam emittance on X-ray polarization through numerical experiments.

Findings

Finite electron beam emittance causes partial depolarization.

Emittance can significantly alter the polarization state of X-ray radiation.

Polarized X-ray generation can be optimized considering beam emittance.

Abstract

In this paper we analyze the polarization of the X-ray radiation coming from laser--electron X-ray generator (LEXG). We obtain general relations connecting the polarization state of outgoing X-ray radiation to the polarization state of laser beam as well as to the parameters of electron beam. We demonstrate that finite electron beam emittance causes a partial depolarization of initially fully polarized X-ray radiation even when the laser beam is fully polarized. We demonstrate with a number of numerical experiments that finite electron beam emittance can in some cases fundamentally alter the polarization state of X-ray radiation as compared to the polarization state of X-ray radiation scattered by electron beam with a zero emittance. Possible applications of polarized LEXG's radiation are discussed.