Heating mechanisms in radio frequency driven ultracold plasmas

TL;DR

This paper analytically investigates various RF-driven heating mechanisms in ultracold plasmas, highlighting how RF fields influence plasma temperature through collisional and collisionless processes, including modifications to recombination dynamics.

Contribution

It provides a detailed analytical study of RF-induced heating mechanisms in ultracold plasmas, emphasizing the effects on three-body recombination and collisionless absorption.

Findings

RF fields modify three-body recombination by ionizing high-lying Rydberg electrons.

Collisionless absorption has a temperature threshold below which it is ineffective.

Heating mechanisms depend on plasma size and temperature, affecting energy transfer processes.

Abstract

Several mechanisms by which an external electromagnetic field influences the temperature of a plasma are studied analytically and specialized to the system of an ultracold plasma (UCP) driven by a uniform radio frequency (RF) field. Heating through collisional absorption is reviewed and applied to UCPs. Furthermore, it is shown that the RF field modifies the three body recombination process by ionizing electrons from intermediate high-lying Rydberg states and upshifting the continuum threshold, resulting in a suppression of three body recombination. Heating through collisionless absorption associated with the finite plasma size is calculated in detail, revealing a temperature threshold below which collisionless absorption is ineffective.