Effect of current sweep rate on critical current of superconducting Ag-Bi-2223 tapes

✍ Scribed by S.Y. Ding; C. Ren; X.X. Yao; Y. Sun; H. Zhang

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 130 KB
• Volume: 38
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(98)00072-1

✦ Synopsis

The effect of sweep rate of applied current (dI/dt) on critical current (I c ) of Ag-sheathed Bi 2 Pb x Sr 2-x Ca 2 Cu 3 O y (Ag-Bi-2223) tapes was studied by the four-probe measurement method of V-I curves. It was found that the V-I curves were affected apparently by dI/dt, resulting I c , decreases with increasing dI/dt for all critical current criterions used here. This result implies that the I c determined at very large dI/dt supplied, for example, by the pule current system will be significantly smaller than the I c measured at small dI/dt usually used in the d.c. method. The possible influences of the present results on published V-I data and I c measurement technique are discussed. We have shown that the ohmic heat at the current contact leads of our Ag-sheathed Bi-2223 samples immersed in liquid nitrogen is negligible.