Field trapping and shielding measurements within a cylindrical hole in a block of Sm-Ba-Cu-O bulk superconductor

Field trapping and shielding experiments were performed using high-T _c bulk superconductor with a cylindrical hole in it. An array of Hall probes was used to measure the field inside the hole as a function of position and applied field. The trapping of magnetic field in the hole was accomplished by cooling the bulk superconductor in the presence of an applied field and then gradually reducing the applied field to zero. Shielding experiments were carried out by cooling the superconductor in the absence of a magnetic field and then gradually applying an external field. This paper describes the results of these experiments.