High Field Diamond Magnetometry Towards Tokamak Diagnostics

TL;DR

This paper demonstrates the use of nitrogen vacancy centers in diamond for high-field magnetometry up to 1.2 Tesla, aiming at applications in tokamak fusion diagnostics, with sensitivities suitable for real-world control systems.

Contribution

It presents the first demonstration of fibre-coupled ensemble NVC magnetometry at magnetic fields exceeding 1 Tesla, relevant for fusion reactor diagnostics.

Findings

Achieved magnetometry sensitivities of 240-600 nT/√Hz at 1.2 T

Demonstrated operation in magnetic fields up to 1.2 T

Validated potential for tokamak diagnostic applications

Abstract

Nitrogen vacancy centres (NVC) in diamond have been widely used for near-dc magnetometry. The intrinsic properties of diamonds make them potential candidates for tokamak fusion power diagnostics, where radiation-hard magnetometers will be essential for efficient control. An NVC magnetometer placed in a tokamak will need to operate within a $\geq$ 1 T magnetic field. In this work, we demonstrate fibre-coupled ensemble NVC optically detected magnetic resonance (ODMR) and magnetometry measurements at magnetic fields up to 1.2 T. Sensitivities of approximately 240 to 600 nT/$\sqrt{\textrm{Hz}}$ and 110 nT/$\sqrt{\textrm{Hz}}$ are achieved in a (10-150) Hz frequency range, for non-degenerate and near-$\langle$111$\rangle$ field alignments respectively.