Development of a modified superconducting magnet for Maglev vehicles

In superconducting magnets for magnetically levitated transport system's (Maglev) vehicles, mechanical loss occurs due to the vibration caused by electromagnetic forces during the train's operation. The heat load including the mechanical loss needs to be reduced within the capability of the onboard refrigerator. It is necessary that the vibration phenomena of the superconducting magnet during the train operation are made clear for the reduction of the mechanical loss. As an important part of the development, it was confirmed that the vibration analysis is accurate enough in comparison with the measured results in running tests on the Yamanashi Maglev Test Line. Moreover, for commercial use, superconducting magnets should be operated with no supply of either liquid helium or liquid nitrogen. To meet the requirement, we have been developing a new type on-board Gifford-McMahon refrigeration (GM refrigerator application) system.