Publication Date

2026

Document Type

Dissertation/Thesis

First Advisor

Salehinia, Iman

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Mechanical Engineering

Abstract

High-Temperature Superconducting (HTS) materials are at the forefront of innovation for fundamental particle physics. The next generation of particle accelerators aims to explore higher mass particles and is dependent on the ability to achieve higher fields in the 20–30 T range to keep machine size within a practical footprint. Current magnet technology relies on low-temperature superconductors (LTS) such as NbTi and Nb₃Sn, which are limited to fields of approximately 8–16 T, while high-temperature superconductors (HTS), particularly Rare-Earth Barium Copper Oxide (REBCO), offer a promising pathway toward higher-field magnets due to their ability to carry large currents at elevated magnetic fields. This work investigates the feasibility of a flat, flexible REBCO cable that combines the high-field performance of HTS materials with the scalability and packing efficiency of traditional LTS Rutherford cables. In collaboration with Fermilab and AMPeers, the influence of key parameters, including tape width (2–6 mm), tape lay angle (30◦ and 45◦), and cable bending diameter (30–40 mm), on critical current performance was evaluated. Prototype samples were fabricated by wrapping REBCO tapes around a Rutherford-type copper cable core, and critical current measurements were performed at 77 K in self-field before and after bending to magnet-relevant diameters. The primary performance metric was critical current retention, with a target of ≥ 90%. Most configurations achieved retention values between approximately 85% and 100%, with some cases exceeding 100%. Trends indicate decreased retention at smaller bending diameters and improved performance at higher lay angles, while the effect of tape width remains inconclusive due to competing mechanical effects and fabrication variability. To support the experimental results, a finite element model was developed in ANSYS to simulate the combined effects of tape wrapping and cable bending, serving as a first-pass predictive tool to evaluate strain in the REBCO layer and explore a broader parameter space. Overall, this study demonstrates the preliminary feasibility of flat REBCO cable geometries for high-field accelerator magnets while identifying key challenges related to mechanical behavior, fabrication consistency, and data interpretation, establishing a foundation for future optimization of HTS conductors in accelerator applications.

Extent

130 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

Download

Share

COinS