High temperature superconductors: advantages and key challenges in their deployment for high-field magnets and large scale applications

Luisa Chiesa

Tufts University

Friday, May 12, 2017

3:00pm

NW17-218

PSFC Seminars

Abstract: After 25 years of development, several high temperature superconductors (HTS) are becoming engineering materials commercially available in long-length wires. Those conductors can carry enormous electrical current in strong magnetic fields while meeting various other challenges. Such characteristics enable the construction of a broad spectrum of devices useful for basic science, medicine, and energy.

In this talk, the state-of-art manufacturing, properties and challenges of key HTS conductors will be discussed with particular focus on REBCO coated conductors. The electrical, magnetic, and mechanical properties and failure mechanisms important for constructing devices will be discussed and examples of large scale projects employing those materials will be given to illustrate the positive impact those new materials could have in future generation’s magnets.

Further details will be given to HTS tape cabling methods for these magnet applications. To improve fabrication methods and maximize operational performance of these cables, it is necessary to characterize both the electromechanical behavior of the full-scale cables and of the individual tapes under anticipated thermal, mechanical and electromagnetic loads. Some laboratory experimentation and structural finite element analysis (FEA) that have been used to investigate the electromechanical behavior of single HTS tapes and Twisted Stacked-Tape Cable (TSTC) conductors will be discussed. The numerical and experimental results discussed in this talk, provide important details about the strain dependence of the critical current for various load types expected during high field magnet operations.

 

Bio: Luisa Chiesa is an associate professor at Tufts University. Before joining the faculty at Tufts in 2009, Dr. Chiesa received her Ph.D. in Nuclear Science and Engineering at MIT and her bachelor in Physics from the Universita’ Statale in Milan (Italy). Dr. Chiesa worked in the field of superconducting magnets for the past 15 years. After a year as a visiting student at Fermilab working on quench protection for the LHC quadrupoles, she joined the Superconducting Magnets group at LBNL where she was heavily involved in the experimental characterization of high field superconducting magnets. Following her Ph.D. work on the transverse load effects on Nb₃Sn used in Cable-in-Conduit Conductors for fusion magnets, her research interest remains in the electro-mechanical characterization of both low temperature and high temperature superconductors for magnets used in large-scale applications. In particular, her laboratory specializes in experimental and numerical techniques to characterize the critical current of superconducting strands, tapes and cables under different mechanical loading conditions.