Publication Date

2026

Document Type

Dissertation/Thesis

First Advisor

Vahabzadeh, Sahar

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Mechanical Engineering

Abstract

Rare Earth Barium Copper Oxide (REBCO) is a High Temperature Superconductor (HTS). REBCO has huge potential for future applications in high-field magnets for medical imaging, fusion energy, and particle accelerators due to its high-performance nature. However, it is prone to mechanical degradation especially under the operational stresses like bending and thermal cycling due to the brittle ceramic nature of REBCO, which ultimately damages the superconducting magnet by degrading its performance or by losing the superconductivity property. Additionally, quench propagation in REBCO tapes is notably slow and difficult to manage, complicating detection and mitigation strategies.

The primary objectives of this research were to investigate the electromechanical behaviour of REBCO tapes subjected to mechanical loading, and to analyze the dynamics of quench propagation. Our goal was to experimentally assess critical current degradation across various bending radii and to simulate quench using CERN’s QLASA software to enhance our understanding of its behavior in REBCO tapes.

Our results show that bending strain has a great impact on the performance of REBCO. Single tapes retained about 95% of their critical current (Ic) at 4 mm and 91% at 3 mm, and 85% at 2 mm, but only 6% at 1 mm bending radii. The face-to-face (F2F) stacks went through a much faster degradation process, being able to retain only ~50% Ic at 6 mm and ~14% at 2 mm. Furthermore, the four-tape stacks also displayed very clear strain dependence as the F2F was able to retain 90%, 84%, and 78% at the bending radii of 2in, 1.5in and 1in, respectively, while back-to-back (B2B) retained 96%, 75%, and 55% at the same radii. The normalized results show that strain effects are more pronounced with the increase in stack height. It is also concluded that REBCO has slow quench propagation as the characterizing factor, with a normal zone propagation velocity (NZPV) of 3.33 ± 0.14 cm/s at 153 A. All these findings together provide the bending-strain sensitivity and quench-propagation characteristics that set the operational limits and reliability of REBCO conductors.

Extent

95 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

Available for download on Friday, June 02, 2028

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