Testing REBCO Critical Current Using a Superconducting Transformer

Published August 20, 2021

Left: E-I curves of the CORC cable at various magnetic fields. Right: Critical current versus magnetic field. The dash line is a fit to the critical current: Ic~B-0.52.

A new device enables the testing of superconducting cables to high current without the high helium consumption associated with traditional current leads. This superconducting transformer will play an important role in testing cables needed for next-generation superconducting magnets.

What did scientists discover?

A superconducting transformer has been co-developed by Lawrence Berkeley National Laboratory and the MagLab [1],[2]. The superconducting transformer is used in the present research as an efficient high current source for measuring very high critical currents of a high-temperature superconducting REBCO cable in high magnetic fields.

Why is this important?

This unique set of data obtained in high magnetic fields and at high electrical current (Figure a, b) characterize the critical current of the sample at liquid helium temperature as a function of magnetic field. This measurement is critical for the development of new state-of-the-art superconducting cables. Funded by the MagLab User Collaboration Grant Program, this research studies a REBCO Conductor-On-Round-Core (CORC) cable which was developed and manufactured by Advanced Conductor Technologies LLC (ACT), a long-time user and collaborator of the MagLab.

Who did the research?

Hui Yu¹, Jun Lu¹, Jeremy Weiss², and Danko van der Laan²

¹National High Magnetic Field Laboratory; ²Advanced Conductor Technologies LLC

Why did the MagLab need to do this research?

This work requires a sophisticated scientific facility, a large 12T split-solenoid superconducting magnet and a superconducting transformer that provides electrical current up to 45 kiloamperes. There are very few laboratories in the world able to provide such a facility. This work demonstrates the critical role the MagLab plays in testing high temperature superconducting cables in magnetic fields, a crucial experiment during the development of such cables, and eventually, necessary to realize high-temperature superconducting magnets constructed from those cables.