Loss in QMG Processed Y-123 Superconductor due to Ac Current


Title, author, abstract

title
Loss in QMG Processed Y-123 Superconductor due to Ac Current
authors
Hiroshi Matsuoka(1), Masayuki Izawa(1), Teruo Matsushita(1,2)
Kazuhiro Kajikawa(3), Masataka Iwakuma(3), Kazuo Funaki(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)Research Institute of Superconductivity, Kyushu University,
6--10--1 Hakozaki, Higashi-ku, Fukuoka 812--81, Japan
abstract
Ac transport current loss is measured for a QMG (Quench and Melt Growth) processed Y-123 bulk superconductor up to 300~A at 77.3~K. For this purpose a simple current transformer is used. The frequency of ac current is 400 and 550~Hz. The hysteresis loss extrapolated to zero~Hz is compared with the prediction of the Irie-Yamafuji model where the critical current density is estimated from the hysteresis of dc magnetization. The obtained hysteresis loss is slightly smaller than the theoretical prediction. This is considered to be caused by the reduction in the critical current density due to the flux creep in the dc magnetization measurement.
Original paper appears in
10th International Symposium on Superconductivity
October 28--30, 1997
Gifu, Japan