Self-field effect and current distribution in Bi(2223) tapes at 77 K

✍ Scribed by G. Grasso; R. Flükiger

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 368 KB
• Volume: 253
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00523-4

✦ Synopsis

The transport critical current distribution of a rolled Bi(2223) tape with jc(77 K, 0 T) = 28 kA/cm 2 has been found to vary from 20 kA/cm 2 at the tape centre to 53 kA/cm 2 at the tape sides. The self-field generated by the high currents flowing in this tape has been studied at the liquid-nitrogen temperature. Numerical calculations of the self-field distribution have been performed, taking into account both the filament shape and the critical current distribution in lateral direction. The self-field component oriented along the tape normal reaches a maximum at the tape sides, and its average value is about 20 G, for a current flowing in the tape equal to I c. This self-field can be drastically reduced by means of a simple experimental setup which is described in the present work. It has been thus possible to determine a more appropriate value of critical current in the absence of magnetic fields, which results in an at least 7% higher value than in the presence of self-field.