In situ electromagnetic field diagnostics with an electron plasma in a Penning-Malmberg trap

TL;DR

This paper introduces a new in situ diagnostic method using an electron plasma in a Penning-Malmberg trap to measure magnetic and microwave electric fields via cyclotron resonance, enabling precise field mapping.

Contribution

The paper presents a novel technique that uses electron plasma as an in situ sensor for magnetic and electric fields in a Penning-Malmberg trap, improving measurement accuracy.

Findings

Successfully measured magnetic field via cyclotron resonance.

Mapped microwave electric field strength spatially.

Demonstrated non-destructive plasma temperature monitoring.

Abstract

We demonstrate a novel detection method for the cyclotron resonance frequency of an electron plasma in a Penning-Malmberg trap. With this technique, the electron plasma is used as an in situ diagnostic tool for measurement of the static magnetic field and the microwave electric field in the trap. The cyclotron motion of the electron plasma is excited by microwave radiation and the temperature change of the plasma is measured non-destructively by monitoring the plasma's quadrupole mode frequency. The spatially-resolved microwave electric field strength can be inferred from the plasma temperature change and the magnetic field is found through the cyclotron resonance frequency. These measurements were used extensively in the recently reported demonstration of resonant quantum interactions with antihydrogen.