The preparation of cylindrical MgB2 films on stainless steel by HPCVD for magnetic shielding.

HT C SQUID has a great potential in ultra-weak magnetic signal detections due to its advantages of energy saving and volume reduction of the overall system, including the cryogenics. However, the application of HT C SQUID is limited because lack of proper magnetic shielding. Superconducting magnetic shielding is an efficient way for HT C SQUID. In this work, we fabricate MgB 2 thick film on a stainless steel cylinder using HPCVD to make a preliminary attempt for SMS with MgB 2 films. High quality MgB 2 film is deposited on the inner side of a hollowed cylinder. The transition temperature of the film is 37.5 K, and the critical current density is 7.6 × 10 6 A⋅cm −2 at 10 K and 4.6 × 10 6 A⋅cm −2 at 20 K, which is comparable with the planar films. The shielding effectiveness of the cylindrical MgB 2 film is numerical simulated. Height and thickness of the cylindrical magnetic shielding designed according to the simulation result was calculated and a corresponding shielding effectiveness of 65 dB is obtained. The numerical result shows the feasibility of using MgB 2 film as magnetic shielding. [ABSTRACT FROM AUTHOR]