Effect of the Aspect Ratio of a Superconducting Tape on the AC Loss in Perpendicular External Magnetic Field

Abstract Recently , intensive efforts to decrease the width of the high -T cuprate superconducting tape for the coated conductors have been made for decreasing the AC loss . It has been found experimentally that the AC loss of the former type of superconducting tape , with the width extremely larger than the thickness , can be described well by the theoretical expression for the superconducting thin strip with the infinite width proposed by Brandt and Indenbom . However , the AC loss in the recent types of tapes , with a much narrower width , is expected to show a noticeable deviation from their expression . In this paper , based on the critical state model , a theoretical expression for the dependence of the AC loss on the aspect ratio in the cross section of the superconducting tape is proposed . Effect of the magnetic -flux -density dependence of the critical current density on the AC loss is also discussed