Symmetric Compton Scattering: A way towards plasma heating and tunable mono-chromatic gamma-rays

Abstract

This paper explores the transition between Compton Scattering and Inverse Compton Scattering (ICS), which is characterized by an equal exchange of energy and momentum between the colliding particles (electrons and photons). This regime has been called Symmetric Compton Scattering (SCS) and has the unique property of eliminating the energy-angle correlation of scattered photons, and, when the electron recoil is large, transferring monochromaticity from one colliding beam to the other, resulting in back-scattered photon beams that are intrinsically monochromatic. The paper suggests that large-recoil SCS or quasi-SCS can be used to design compact intrinsic monochromatic γ-ray sources based on compact linacs, thus avoiding the use of GeV-class electron beams together with powerful laser/optical systems as those typically required for ICS sources. Furthermore, at low recoil and low energy collisions (in the 10 keV energy range), SCS can be exploited to heat the colliding electron beam, which is widely scattered with large transverse momenta over the entire solid angle, offering a technique to trap electrons into magnetic bottles for plasma heating.