Development of World's Largest High-Temperature Superconducting Magnet with 20-cm-Diameter Room-Temperature Bore

摘要

A cryocooled high-field high-temperature superconducting (HTS) magnet, which has a room-temperature bore 20 cm in diameter, has been developed and tested up to 8.1 T. The size of the magnet is 900 mm in major axis, 600 mm in minor axis, and 540 mm in height. The total coil weight is 320 kg. The largest HTS magnet ever developed had a room-temperature bore of 50 mm in diameter and a magnetic field of 7.1 T at the center. The new HTS magnet employs the newly developed "DI-BSCCO wire" (dynamically innovative bismuth-based HTS wire). Because Dl-BSCCO has the strong mechanical properties, the new magnet does not have any reinforcement material in the coils. The magnet is directly conduction cooled to 20 K, and therefore the specific heat at 20K is hundred times larger than that at 4 K. This means that small thermal disturbances in coils do not cause the magnet to quench. This magnet can be used in various industries such as bio-medicine, semiconductor and environment.