Electron Plasmas Cooled by Cyclotron-Cavity Resonance

TL;DR

This paper demonstrates that high-Q electromagnetic cavity resonances significantly enhance the cyclotron cooling rate of electron plasmas in a Penning-Malmberg trap, with potential increases by factors of ten or more, depending on resonance conditions.

Contribution

It provides a detailed experimental investigation of how cavity resonances can be used to control and improve plasma cooling rates in electron confinement devices.

Findings

Cooling rate can be increased by factors of ten or more.

Resonance conditions depend on magnetic field tuning and cavity mode matching.

Plasma temperature and density influence the effectiveness of cavity cooling.

Abstract

We observe that high-Q electromagnetic cavity resonances increase the cyclotron cooling rate of pure electron plasmas held in a Penning-Malmberg trap when the electron cyclotron frequency, controlled by tuning the magnetic field, matches the frequency of standing wave modes in the cavity. For certain modes and trapping configurations, this can increase the cooling rate by factors of ten or more. In this paper, we investigate the variation of the cooling rate and equilibrium plasma temperatures over a wide range of parameters, including the plasma density, plasma position, electron number, and magnetic field.