Fabrication of 5 T Magnet Using 2G Wires Directed at Maglev Application

Our research target is to apply 2G wires to on-board magnets of the Maglev. The 2G wire enables conduction cooling of the magnet and reduction of the total weight of Maglev vehicles. We fabricated a small radiation shieldless magnet using 2G wires capable of generating a magnetic flux density of 5 T at 45 K. The purpose of the magnet is to demonstrate that 2G wires can realize 5 T at high temperature and achieve the same current density as that of the exiting LTS on-board magnet. Also, this high operation temperature enables radiation shieldless cryostat structure. That means further weight reduction and simplification of the on-board magnet. In this demonstration of a 5-T magnet, we also tested the cyanoacrylate impregnation technique. The superconducting coils for the on-board magnets need to have a mechanically strong structure. Therefore, these coils have to be placed in metal cases and impregnated. However, epoxy impregnation may cause damage to 2G wires. We have solved this problem by using cyanoacrylate or wax impregnation. Cyanoacrylate resin has a moderate bonding strength, and does not damage 2G wires.