Superconducting magnet and on-board refrigeration system on Japanese MAGLEV vehicle

Running tests on the Miyazaki test track are repeatedly carried out to speeds over 300 km/h using the magnetically levitated (MAGLEV) vehicle MLU002. The development of the MAGLEV system for the new test line has already started, and a new superconducting magnet for it has been manufactured. An onboard refrigerator is installed in the superconducting magnet to keep the liquid-helium temperature without the loss of liquid helium. The helium gas produced when energizing or deenergizing the magnet is stored in onboard gas helium tanks temporarily. The onboard refrigerator is connected directly to the liquid-helium tank of the magnet. Thus, the stored helium gas can be reliquefied easily by the onboard refrigerator. In order to minimize the volume of the helium gas produced when energizing and deenergizing the magnet, the power leads of the magnet, superconducting coils and persistent current switches have been improved. The energization and deenergization of the magnet can be finished in 1 to 2 min