Current–voltage characteristics of Bi-2223/Ag multifilamentary tapes exposed to inhomogeneous magnetic field

✍ Scribed by Jozef Kvitkovic; Milan Polak

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 316 KB
• Volume: 401
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2003.09.026

✦ Synopsis

Bi-2223/Ag tapes in some winding sections of magnets, transformers, motors and generators are exposed to inhomogeneous magnetic fields. Current-voltage (I-V ) curves and critical currents are usually measured in homogeneous magnetic field and the determination of critical current in the case of inhomogeneous magnetic field is not a standard procedure. We measured I-V curves of three different multifilamentary Bi-2223/Ag tapes in inhomogeneous and in homogeneous external magnetic fields with the aim to determine and compare the critical currents in both cases. In our simple model we supposed inhomogeneous field with constant field gradient across the tape width. We assumed that the critical current in inhomogeneous magnetic field is the same as that measured in homogeneous magnetic field at the magnetic field value which is equal to the mean value of the inhomogeneous magnetic field across the tape width. From measurements we have found that our tapes in inhomogeneous magnetic field had critical current slightly higher (+2.5%) than that in homogeneous field (Tape 2 and Tape 3) or critical currents were practically identical (Tape 1).