Tesseract – a high-stability, low-noise fluxgate sensor designed for constellation applications

[摘要] Accurate high-precision magnetic field measurements are asignificant challenge for many applications, including constellation missions studying space plasmas. Instrument stability and orthogonality are essentialto enable meaningful comparison between disparate satellites in aconstellation without extensive cross-calibration efforts. Here we describethe design and characterization of Tesseract – a fluxgate magnetometersensor designed for low-noise, high-stability constellation applications.Tesseract's design takes advantage of recent developments in themanufacturing of custom low-noise fluxgate cores. Six of these custom racetrack fluxgate cores are securely and compactly mounted within a singlesolid three-axis symmetric base. Tesseract's feedback windings areconfigured as a four-square Merritt coil to create a large homogenousmagnetic null inside the sensor where the fluxgate cores are held in a near-zero field, regardless of the ambient magnetic field, to improve thereliability of the core magnetization cycle. A Biot–Savart simulation is used to optimize the homogeneity of the field generated by the feedback Merrittcoils and was verified experimentally to be homogeneous within 0.42 % along the racetrack cores' axes. The thermal stability of the sensor'sfeedback windings is measured using an insulated container filled with dryice inside a coil system. The sensitivity over temperature of the feedbackwindings is found to be between 13 and 17 ppm  ∘ C −1 . The sensor's three axes maintain orthogonality to withinat most 0.015 ∘ over a temperature range of −45 to 20  ∘ C. Tesseract's cores achieve a magnetic noise floor of 5 pT  √ Hz −1 at 1 Hz. Tesseract will be flight demonstrated on theACES-II sounding rockets, currently scheduled to launch in late 2022 andagain aboard the TRACERS satellite mission as part of the MAGIC technologydemonstration which is currently scheduled to launch in 2023.

[学科分类] 再生能源与代替技术