The In-Plane Magnetic Field Measurement Method of SC/MR Mixed Sensor and Its Three-Axis Magnetic Sensor With Integrated Magnetic Concentrator

Abstract

Superconductor/magnetoresistance (SC/MR) mixed sensor has the advantage of ultrahigh sensitivity and is thought to be a promising candidate for weak magnetic field detection. However, it has no effect on the magnetic field in the superconducting flux-to-field transformation amplifier (SFTA) plane, which limits its applications in 3-D magnetic field detection. Here, we present a new architecture of SC/MR mixed sensor with only one integrated magnetic concentrator (IMC) to realize the in-plane magnetic field measurement. Firstly, the conversion efficiency, defined as the in-plane magnetic changing to the out-plane magnetic field by the IMC and SFTA of mixed sensor, was systematically studied by the finite element analysis method, the results show that the high conversion efficiency is from the combined action of superconducting diamagnetism and magnetic concentrator of soft magnetic materials. Then, a serial prototype mixed sensors with different IMC relative configuration sizes were prepared and their experimental performances were obtained. Indeed, the mixed sensor with IMC can simultaneously measure the in-plane and out-of-plane magnetic fields, furthermore, the conversion efficiency changes as the function of the relative configuration size is consistent well with the simulation result. Finally, a three-axis SC/MR mixed sensor scheme and its corresponding three-axis magnetic field decoupling method based on this method were also proposed, showing the obvious capability of three-axis magnetic field measurement. Our work is meaningful to the development of a three-axis weak magnetic field detection.