Tensor gradiometry with a diamond magnetometer

TL;DR

This paper introduces a fiber-coupled NV center vector magnetometer with feedback control, capable of real-time magnetic tensor gradiometry imaging, enhancing damage detection in steel structures under extreme conditions.

Contribution

It presents a novel scanning fiber-coupled NV center magnetometer with feedback control for real-time vector magnetic field and tensor gradiometry imaging in challenging environments.

Findings

Real-time magnetic tensor gradiometry imaging achieved.

Enhanced damage detection compared to scalar or vector imaging.

Operates effectively in extreme conditions.

Abstract

Vector magnetometry provides more information than scalar measurements for magnetic surveys utilized in space, defense, medical, geological and industrial applications. These areas would benefit from a mobile vector magnetometer that can operate in extreme conditions. Here we present a scanning fiber-coupled nitrogen vacancy (NV) center vector magnetometer. Feedback control of the microwave excitation frequency is employed to improve dynamic range and maintain sensitivity during movement of the sensor head. Tracking of the excitation frequency shifts for all four orientations of the NV center allow us to image the vector magnetic field of a damaged steel plate. We calculate the magnetic tensor gradiometry images in real time, and they allow us to detect smaller damage than is possible with vector or scalar imaging.