| 摘要 |
PURPOSE:To prevent a cooling agent from flowing over or the evaporation amount of the cooling agent from remarkably increasing caused by the invasion heat of the cooling agent flowing into the port when a magnet is turned both vertically and horizontally, by making a port provided on a cryostat stand at an edge part in the manner that the slant angle with respect to the axial center is made to be approximately 45 deg.. CONSTITUTION:A port 3 provided on a cryostat is formed so that an inner pipe 3a continuing to an inner container 7 and an outer pipe 3b continuing to an outer container 9 are concentrically arranged with a heat insulating layer 8a continuing to a heat insulating layer 8 between the inner and outer containers, and is made to stand with an angle theta of approximately 45 deg. with respect to the horizontal plane at the edge part where a peripheral wall 2b of the cryostat is perpendicular to the other side wall 2a. Since a liquid surface of a cooling agent 10 is kept below the root terminal of the port 3 in both horizontal and vertical directions, the cooling agent does not flow out from the port. The liquid level of the cooling agent 10, permitting invasion of heat from outside, separates apart from the port, preventing the evaporation amount of the cooling agent from increasing. |
