Resistive and sympathetic cooling of highly-charged-ion clouds in a Penning trap

TL;DR

This paper investigates resistive and sympathetic cooling of highly-charged ion clouds in a Penning trap, revealing deviations from exponential cooling and a quadratic charge dependence in sympathetic cooling, advancing understanding of plasma cooling dynamics.

Contribution

It provides experimental insights into cooling behaviors of ion clouds in Penning traps, including a new energy-transfer model and charge-dependent sympathetic cooling effects.

Findings

Resistive cooling deviates from exponential behavior due to energy transfer.

Sympathetic cooling shows quadratic dependence on ion charge state.

Results align with dilute non-neutral plasma physics.

Abstract

We present measurements of resistive and sympathetic cooling of ion clouds confined in a Penning trap. For resistive cooling of a cloud consisting of one ion species, we observe a significant deviation from exponential cooling behavior which is explained by an energy-transfer model. The observed sympathetic cooling of simultaneously confined ion species shows a quadratic dependence on the ion charge state and is hence in agreement with expectations from the physics of dilute non-neutral plasmas.