星载感应式空心磁芯磁传感器的研究

Inductive magnetic sensor with hollow core for space applications

优化设计了频率带宽为1 Hz^10 k Hz的空心磁芯感应式磁传感器。首先提出空心结构的磁芯,分析空心磁芯的退磁因数和有效磁导率,并仿真、实测空心磁芯感应线圈的磁通,得出一定壁厚的空心磁芯感应线圈的磁通可以等于相同长径比棒状磁芯感应线圈的磁通。然后分析空心磁芯感应式磁传感器的灵敏度与噪声,通过数学算法优化噪声公式达到要求的噪声指标和较低的重量。为验证理论分析,设计空心磁芯感应式磁传感器,在屏蔽室对空心磁芯感应式磁传感器的性能进行测试,频率高于400 Hz时灵敏度为0.73 V/n T。100 Hz时噪声为0.06 p T/Hz1/2,总重量为80 g。实测的空心磁芯感应式磁传感器的灵敏度与噪声和理论分析一致。空心磁芯感应式磁传感器与THEMIS相比具有噪声低、重量轻的优点,能够满足空间电磁探测的实用条件。

This paper optimally designs a hollow-core inductive sensor with bandwidth range from 1 Hz to 10 kHz. Firstly, we utilize a magnetic core with hollow structure, and analyze demagnetizing factor and efficient magnetic permeability of hollow core. The magnetic flux of hollow core sensor coil is simulated and measured, and is found equal to the one of rod core sensor coil with the same ratio of length and diameter. Then, sensitivity and noise of inductive magnetic sensor with hollow core are analyzed and the performances of low noise and low weight are achieved by optimizing the noise formula using mathematic algorithm. To verify the theoretical analysis, this paper designs an inductive magnetic sensor with hollow core and tests the performance of the inductive magnetic sensor with hollow core in shielded environment yielding sensitivity of 0.73 V/nT corresponding the frequency higher than 400 Hz and noise of 0.06 pT/Hz1/2 at frequency of 100 Hz. Under this condition, the whole configuration weighs 80 g. The process is consistent with the theoretical analysis. Compared with THEMIS, the inductive magnetic sensor with hollow core has merits of low noise and light weight, and can satisfy the needs of Space Electromagnetic Science.