Cryogenic cooling apparatus and cryogenic cooling method for cooling object to very low temperatures

摘要

A coil unit (41) and a refrigeration unit (42) are positioned such that a second heat conductive member (55) disposed on an extendible wall (54) of a vacuum container (43) and a fourth heat conductive member (74) disposed on an extendible wall (73) of another vacuum container (60) face each other coaxially. In this state, the coil unit (41) and refrigeration unit (42) are relatively moved to approach each other, and thus the second heat conductive member (55) and fourth heat conductive member (74) come in contact. If the coil unit (41) and refrigeration unit (42) are further moved, the extendible wall (54) extends and consequently the second heat conductive member (55) comes in contact with a first heat conductive member (49). In addition, the extendible wall (73) contracts and consequently the fourth heat conductive member (74) comes in contact with a third heat conductive member (62). Thus, a superconducting coil (44) is thermally connected to the refrigeration unit (42) so that the superconducting coil is cooled.