Design and Construction of a Superconducting Gravimeter Prototype

To promote China's research on fields related to high-accuracy gravity measurement, the Institute of Electrical Engineering, Chinese Academy of Sciences (IEECAS), is committed to developing superconducting gravimeters. A superconducting gravimeter prototype has been successfully designed, fabricated, and tested through continuous improvement and optimization design. This article describes the main components of the prototype: superconducting gravity sensor, magnetic shield, cryogenic system, and displacement detection and feedback system. The novel work improves the superconducting gravity sensor on the persistent current switch and superconducting joint. Furthermore, the method for testing the levitation stiffness is also introduced, and the result demonstrates that an electromagnetic force method is a feasible approach with fast and good linearity. Finally, experimental test results on the prototype are shown, where solid Earth tide, temperature effect, and parasitic mode are obtained in the prototype signal. Moreover, it is shown that the levitation stiffness obtained by the electromagnetic force method and the tidal observation method are close to each other.