Contributors to fluxgate magnetic noise in permalloy foils including a potential new copper alloy regime

<p>Fluxgate magnetometers provide sensitive and stable measurements of the static and low-frequency vector magnetic field. Fluxgates form a magnetic field measurement by periodically saturating a ferromagnetic core and the intrinsic magnetic noise of this material can determine the noise floor...

Full description

Bibliographic Details
Main Authors: D. M. Miles, R. Dvorsky, K. Greene, C. T. Hansen, B. B. Narod, M. D. Webb
Format: Article
Language:English
Published: Copernicus Publications 2022-03-01
Series:Geoscientific Instrumentation, Methods and Data Systems
Online Access:https://gi.copernicus.org/articles/11/111/2022/gi-11-111-2022.pdf
Description
Summary:<p>Fluxgate magnetometers provide sensitive and stable measurements of the static and low-frequency vector magnetic field. Fluxgates form a magnetic field measurement by periodically saturating a ferromagnetic core and the intrinsic magnetic noise of this material can determine the noise floor of the instrument. We present the results of an empirical experiment to understand the physical parameters that influence the intrinsic magnetic noise of fluxgate cores. We compare two permalloy alloys – the historical standard 6 % molybdenum alloy and a new 28 % copper alloy. We examine the influence of geometry using the historical standard 1 in. diameter spiral-wound ring core and a new stacked washer racetrack design. We evaluate the influence of material thickness by comparing 100 and 50 <span class="inline-formula">µm</span> foils. Finally, we investigate heat treatments in terms of temperature and ramp rate and their role in both grain size and magnetic noise. The results of these experiments suggest that thinner foils, potentially comprising the copper alloy, manufactured into continuous racetrack geometry washers may provide excellent performance in fluxgate sensors.</p>
ISSN:2193-0856
2193-0864