基于高温超导体的真空动态微力测量平台研究

Study on vacuum dynamic micro-force measuring platform based on high temperature superconductor

针对α衰变微推进器等高辐射性、附着式空间微推进器的测量需求,提出了一种基于高温超导磁悬浮装置的真空动态微小力测量方法和平台。平台利用液氮、分子泵和高温超导体构建了低温、低压、低阻的实验条件,避免了接触型阻力的存在。实验时,硬磁转子将悬浮在超导导轨上进行单自由度的平面转动运动。通过光电测速系统对硬磁转子进行的较远距离长时间监测,实现了对微小力的测量,也减小了可能的放射性危害。重点介绍了微小力测量平台的关键子系统,分析了平台的运动特征与测力机制,给出了实验流程与数据处理方法,并进行了标定实验。经标定,平台可实现小于1μN的推力测量。平台的阻力可低至511±35 nN,微力测量的下限为66 nN。

Aiming at the measurement requirements of high radiation and attached space microthrusters, such as alpha decay microthrusters, a new vacuum dynamic micro-force measuring platform based on high temperature superconducting maglev device is proposed in this paper. An experiment condition of low temperature, low pressure and low resistance is established by liquid nitrogen, molecular pump and high temperature superconductors, which avoids the existence of contact resistance. In the experiment, the hard magnetic rotor will suspend on the superconducting guide rail for a single degree of freedom plane rotation. A photoelectric speed measurement system is used to perform long term monitoring on the motion state of hard magnetic rotor remotely, the micro force measurement is achieved and the possible radioactive hazard is reduced. The paper introduces the key subsystems of the micro-force measuring platform, analyzes the motion characteristics and force measuring mechanism of the micro-force measuring platform. In addition, the experiment flow chart and data processing method are given. Calibration test was conducted, and after calibration the platform can realize the measurement of the thrust less than 1 μN. The resistance of the platform is as low as 511±35 nN, and the bottom boundary of micro force measurement is 66 nN.