Thomson and Compton scattering with an intense laser pulse

TL;DR

This paper investigates the relationship between nonlinear Compton and Thomson scattering of intense laser radiation on electrons, deriving classical limits of quantum emission spectra and analyzing polarization effects.

Contribution

It provides a unified derivation of classical and quantum radiation distributions for arbitrary laser polarization, extending previous results to more general conditions.

Findings

Classical and quantum spectral distributions are derived and compared.

Differences between classical and quantum results are identified and illustrated.

Results generalize previous work to arbitrary laser polarization.

Abstract

Our paper concerns the scattering of intense laser radiation on free electrons and it is focused on the relation between nonlinear Compton and nonlinear Thomson scattering. The analysis is performed for a laser field modeled by an ideal pulse with a finite duration, a fixed direction of propagation and indefinitely extended in the plane perpendicular to it. We derive the classical limit of the quantum spectral and angular distribution of the emitted radiation, for an arbitrary polarization of the laser pulse. We also rederive our result directly, in the framework of classical electrodynamics, obtaining, at the same time, the distribution for the emitted radiation with a well defined polarization. The results reduce to those established by Krafft et al. [Phys. Rev. E 72, 056502 (2005)] in the particular case of linear polarization of the pulse, orthogonal to the initial electron momentum. Conditions in which the differences between classical and quantum results are visible are discussed and illustrated by graphs.