Refrigerated high-Tc superconducting devices

Abstract
The successful development of refrigerated superconducting magnets has greatly enhanced the functionality of superconducting devices. By eliminating the need for liquid cryognes the size, weight, and cost of superconducting devices is substantially reduced. For example, coils wound with Nb 3Sn conductor can be operated at approximately 10 K by using a two‐stage Gifford‐McMahon closed‐cycle refrigerator. As reported herein, prototype refrigerated magnets using Nb 3Sn have been successfully fabricated and tested. As high‐T c superconductors become available in longer lengths and with higher current densities, the refrigerated magnet technology can be efficiently utilized to operate high‐T c devices above 10K. Three enabling technologies are critical to success of high‐T c refrigerated superconducting devices: high‐T c materials development, reliable cryogenic refrigeration, and high‐T c coil design methodology. An overview of these enabling technologies is presented in this paper, with a discussion of the future developments required to ensure the viability of refrigerated high‐T c devices.