Flux Trapping in Hollow Soft Superconducting Cylinders

Flux trapping measurements in hollow super conducting lead cylinders were undertaken to determine whether the reduction in trapped field is due to the length of the cylinder or whether even an infinitely long cylinder would display similar behavior. An infinitely long hollow cylinder was simulated by arranging a niobium guard ring at each end of the cylinder. The experiments seem to indicate that magnetic fields as large as the critical field may be stably trapped in soft superconducting cylinders. (C.E.S.)