Superconducting magnets (SCM) for Maglev Trains are vibrated by several mechanical and electro-magnetic disturbances. The main disturbance is the vibration caused by the magnetic field fluctuation, which arises from the ground coils. Heat load and vibration characteristics under these conditions have been evaluated by electro-magnetic disturbance tests which are to simulate actual running conditions. Through the electro-magnetic disturbance tests with an initial type SCM which was made in 1990 on an experimental basis, it became clear that the heat load was more than several 10W under a specific frequency, which exceeded the cryogenic refrigeration capacity. As the result of the analysis of heat load and vibration of the SCM, it was estimated that the heat load was caused by the eddy current which was due to the relative vibration between the radiation shield plate (aluminum) and the inner vessel under the magnetic flux of the SCM. The mechanism of heat load generation by the vibration between the radiation shield plate and the inner vessel, and a method of reducing heat load are discussed here.
