Magnetic shielding and relaxation characteristics of superconducting YBa2Cu3O7 tubes

Abstract
High‐Tc superconducting tubes have been developed for magnetic shielding of SQUIDs at 77 K. The characteristics of such tubes show that adequate shielding exists for magnetic fields up to a critical field determined by the current density of the tube. Relaxation phenomena with two different time dependencies are observed when the external magnetic field enters the tubes.