Design, Construction, and Operational Testing of Dry-Wound Conduction-Cooled React-and-Wind MgB$_{2}$ Magnet

Abstract

This study details the design, construction, and operational testing of a dry-wound conduction-cooled react-and-wind MgB$_{2}$ magnet. A turn-coloring method was employed for the precise dry winding of round wire, ensuring the winding was completed as per design specifications. Mechanically and thermally stable copper ring-shaped current lead structures with solder-filled helical grooved path were developed for the reacted wire. Following the cryogen-free cooling setup, the magnet was charged, resulting in a quench event at a current lower than the designed operating level. Analysis suggests that an unexpected heat source within the coil winding, combined with the absence of a pre-load structure that resulted in insufficient conduction cooling paths, led to localized heat accumulation and a subsequent quench. These findings highlight the need for improvements in magnet design and manufacturing, particularly in incorporating a coil pre-load structure to enhance thermal management and ensure the long-term reliability of conduction-cooled MgB$_{2}$ magnets.