Design and Test of a Magnetic-Field Compensation Coil Without Interference With the Door of a Magnetically Shielded Room

A magnetically shielded room (MSR) is the fundamental device in the research of extremely weak magnetic fields, and the cost-effective improvement of its magnetic shielding performance is very critical to ensure its practicality. Thus, this study proposes a method for designing a new type of magnetic-field compensation coil that clings to the outer part of MSR without interfering with its door. In the method, the irregular outer coils and inner compensating coils are combined to increase the uniform area and suppress the cross-coupling effect. Thereafter, the feasibility of the method is theoretically and experimentally verified. The proposed method will lay a foundation for designing the active magnetic compensation system for the MSR exhibiting large uniform areas, high shielding efficiency, and especially low cost.