Investigation on intense axial magnetic field shielding with a large melt cast processed Bi-2212 tube

The feasibility of shielding axial magnetic fields up to 1.4 T, using a Bi-2212 hollow cylinder, is investigated at a temperature of 4.2 K. The residual magnetic flux density along the axis of the tube is measured at external fields of 1 T and 1.4 T. The shielding factor, defined as the ratio between the applied and the residual magnetic flux densities at the center of the tube, is measured to be 32x104 at 1 T and 12x103 at 1.4 T. The induced current density is evaluated from the measurements taking the thickness of the tube into account. The stability of the measurements over time is also addressed. Numerical simulations for the external and the residual magnetic flux densities are performed and compared to the experimental results. The study shows a high shielding performance of the Bi-2212 superconductor tube at 4.2 K up to 1.4 T.