A hybrid fluxgate and search coil magnetometer concept using a racetrack core

Abstract

Abstract. A proof-of-concept hybrid magnetometer is presented, which simultaneously operates as both a fluxgate and a search coil, allowing it to sense the magnetic field from DC to 2 kHz using a single sensor. Historically, such measurements would normally require two dedicated instruments, and each would typically require deployment on its own dedicated boom as the instruments mutually interfere. A racetrack fluxgate core combined with a long solenoidal sense winding is shown to be moderately effective as a search coil magnetometer, and the search coil effect can be captured without introducing significant hardware complexity beyond what is already present in a typical fluxgate instrument. Several methods of optimising the search coil action of the hybrid instrument are compared with the best method providing sensitivity and noise performance between comparably sized traditional air-core and solid-core search coil instruments. This hybrid sensor topology should miniaturise to platforms such as CubeSats for which multiple boom-mounted instruments are generally impractical, so a single hybrid instrument providing modest, but scientifically useful, sensitivity from DC to kHz frequencies would be beneficial.

Research on the Orthogonal Fundamental Mode Fluxgate Sensor Circuit

“…The diameter of the amorphous wire is 120 μm, the length is 2 cm, the resistance is 2.7 Ω, the diameter of the pick-up coil is 0.1 mm, the outer layer of the amorphous wire is wound with 1200 turns, and the resistance is 112 Ω. The two ends of the amorphous wire are connected with an excitation current signal, and the pick-up coil outputs a voltage signal that responds to the magnetic field information [15]- [17].…”