Measurement of joint properties of Bi(Pb)-Sr-Ca-Cu-O (2223) tapes by field decay technique

Author

Kim, Jung Ho ; Kim, Kyu Tae ; Jang, Seok Hern ; Joo, Jinho ; Choi, Seyong ; Nah, Wansoo ; Kang, Hyoungku ; Ko, Tae Kuk ; Ha, Hong-Soo ; Oh, Sang-Soo ; Ryu, Kang-Sik ; Nash, Philip

Author_Institution

Sch. of Metall. & Mater. Eng., SungKyunKwan Univ., Suwon, South Korea

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

2992

Lastpage

2995

Abstract

We joined 19-multifilamentary Bi-2223 superconductor tapes and fabricated double-pancake coils by using resistive- and superconducting-joint methods. The critical current ratio (CCR) of the jointed tape and the decay characteristics, joint resistance, and n-value of the pancake coils were evaluated. The joint resistance of the coils was characterized by the field decay technique. It was observed that the CCR was higher in the joined tape made by the resistive-joint method, compared to that by the superconducting-joint method. On the other hand, joint resistance was measured to be 4 orders of magnitude smaller in the superconducting-joint coil; approximately 40% of critical current was retained in the persistent current mode and the joint resistance was 0.18 nΩ. Better and longer retention of the magnetic field in the superconducting-joint coil is believed to be due to the direct connection between the superconducting cores.

Keywords

bismuth compounds; calcium compounds; critical currents; high-temperature superconductors; joining processes; lead compounds; multifilamentary superconductors; persistent currents; strontium compounds; superconducting coils; superconducting tapes; (BiPb)₂Sr₂Ca₂Cu₃O; Bi-2223 multifilamentary superconductor tape; critical current ratio; double-pancake coil; field decay technique; joint resistance; magnetic field; n-value; persistent current mode; resistive joint method; superconducting joint method; Critical current; Current measurement; Electrical resistance measurement; Magnetic field measurement; Nuclear magnetic resonance; Persistent currents; Superconducting coils; Superconducting films; Superconducting magnets; Thermal degradation;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.812049

Filename

1212252