Superconductor/magnetoresistance mixed sensor with magnetic flux guides for in-plane magnetic field measurement

A superconductor/magnetoresistance (SC/MR) mixed sensor often has very high-precision detection capability, but it is only sensitive to the out-of-plane magnetic field that is perpendicular to the superconducting flux-to-field transformation amplifier (SFTA). This inherent characteristic makes it impossible for a primary SC/MR mixed sensor to measure the in-plane magnetic field, which limits its application in many fields. This paper presents a new architecture of SC/MR mixed sensors with two magnetic flux guides (MFGs) to realize in-plane magnetic field measurement, which is attributed to the combined effects of MFGs and SFTA. The finite element method simulations are used to study the magnetic flux converting effect of MFGs and magnetic field amplification effect of SFTA, which theoretically proves the feasibility of in-plane magnetic field measurement and reveals the influences of the sizes and spacing of MFGs on magnetic field magnification. Experimental results show that the SC/MR mixed sensor with MFGs can simultaneously sense the in-plane and out-of-plane magnetic fields, and the performance of the mixed sensor with MFGs is comparable to the primary one. The magnification and resolution of the mixed sensors with MFGs to the in-plane magnetic fields are, respectively, improved by 2.91 times and 2.23 times compared to those without MFGs to the out-of-plane magnetic fields. The work described in this paper is of great significance for the development of three-component weak magnetic field detection.