### Title, author, abstract

title
Dependence of Irreversibility Field on the Thickness of Superconducting Layer
authors
Miki Tagomori(1), Masaru Kiuchi(1), Teruo Mstsushita(1,2)
Takayo Hasegawa(3)
(1)Department of Computer Science and Electronics, Kyushu Institute of Technology,
680--4 Kawazu, Iizuka, 820 JAPAN
(2)Graduate School of Information Science and Electrical Engineering (ISEE), Kyushu University,
6--10--1 Hakozaki, Higashi-ku, Fukuoka 812--81, Japan
(3)Showa Electric Wire and Cable Co. Ltd., 2--1--1 Odasakae, Kawasaki-ku, Kawasaki 210, Japan
abstract
The irreversibility field was observed for two multilayered Bi-2212 tape wires with different thicknesses of superconducting layers. The irreversibility field does not depend on the thickness of superconducting layers but is determined only by the flux pinning strength. The result agrees well with the theoretical analysis of the flux creep-flow model. The analysis shows that the longitudinal flux bundle size is of the order of a few $\mu$m on the irreversibility line. The present experimental result is reasonable, since the flux bundle size is shorter than the thickness of superconducting layers, resulting in the three-dimensional pinning.
Original paper appears in
10th International Symposium on Superconductivity
October 28--30, 1997
Gifu, Japan