Patent ID: 7132914

Claim:
A superconducting magnet apparatus comprising: a superconducting coil cooled inside a vacuum container; a first current lead fixed inside the vacuum container, one end of the first current lead being connected to the superconducting coil and the other end having a lead contact portion; and a second current lead passing through a through-hole provided on the vacuum container in an air-tight manner, one end of the second current lead being connected to a lead line leading to an external excitation power source and the other end having an attachment/detachment portion detachably disposed with respect to the lead contact portion, the superconducting magnet apparatus being switched to a persistent current mode by an electric current supplied from the external excitation power source under a condition that the attachment/detachment portion is in contact with the lead contact portion, the attachment/detachment portion being then separated from the lead contact portion and the apparatus maintaining the persistent current mode, wherein the superconducting magnet apparatus further comprises a drive mechanism made from a nonmagnetic insulating body for automatically moving the attachment/detachment portion back and forth in an attachment/detachment direction with respect to the lead contact portion, in response to a voltage applied by an external drive power source.