# Remote detection of rotating machinery with a portable atomic magnetometer

## TL;DR

This paper presents a portable atomic magnetometer system capable of remotely detecting rotating machinery in unshielded environments by sensing AC magnetic signatures, with potential applications in industrial monitoring and security.

## Contribution

The study introduces a portable atomic magnetometer that detects rotating machinery remotely without shielding, outperforming traditional fluxgate sensors in certain conditions.

## Key findings

- Comparable or better performance than commercial fluxgate sensors
- Effective detection behind walls
- Optimized detection through spectral tuning

## Abstract

We demonstrate remote detection of rotating machinery, using an atomic magnetometer at room temperature and in an unshielded environment. The system relies on the coupling of the AC magnetic signature of the target with the spin-polarized, precessing atomic vapor of a radio-frequency optical atomic magnetometer. The AC magnetic signatures of rotating equipment or electric motors appear as sidebands in the power spectrum of the atomic sensor, which can be tuned to avoid noisy bands that would otherwise hamper detection. A portable apparatus is implemented and experimentally tested. Proof-of-concept investigations are performed with test targets mimicking possible applications, and the operational conditions for optimum detection are determined. Our instrument provides comparable or better performance than a commercial fluxgate and allows detection of rotating machinery behind a wall. These results demonstrate the potential for ultrasensitive devices for remote industrial and usage monitoring, security, and surveillance.