Collisionless Beam-Radiation Processes in the Laboratory and Astrophysics

TL;DR

This paper explores plasma instabilities in relativistic plasmas, focusing on beam-beam and coherent synchrotron radiation instabilities, with applications in astrophysics and particle accelerators, analyzing their effects and modeling their spectra.

Contribution

It develops simple models based on the linearized Vlasov equation and relativistic magnetohydrodynamics to compute radiation spectra from plasma instabilities.

Findings

Beam-beam instability limits luminosity in storage rings.

Coherent synchrotron radiation causes significant energy losses.

Models successfully predict spectra of emitted radiation.

Abstract

Plasma instabilities can be encountered in many branches of physics. This work focuses on relativistic plasmas with applications in theoretical astrophysics and particle accelerator physics. Even though these fields seem to be unrelated the underlying plasma physics processes are often very similar. Two plasma instabilities - the beam-beam instability and the coherent synchrotron radiation instability - are analyzed. The former severely limits the achievable luminosity in storage rings and is related to the two-stream instability which has been proposed as a candidate for the radiation mechanism of radio pulsars. The main emphasis is on coherent synchrotron radiation which can lead to prohibitive energy losses in bunch compressors. Coherent synchrotron radiation also makes up the intense emission of radio waves by pulsars. Simple models based on the linearized Vlasov equation and relativistic magnetohydrodynamics which allow to compute detailed spectra of the emitted radiation are developed.