| 摘要 |
<p>PURPOSE: To provide a helium transfer tube where the cost is low and the evacuation time is short. CONSTITUTION: Piping 5 for liquid nitrogen is provided at the center on the outer side of a longer side of a shield plate 4 whose section is rectangular, and an outermost tube 1 is provided around a shield plate 4 and th piping 5 for liquid nitrogen. This constitution eliminates the projection such as the piping 5 for liquid nitrogen of the conventional example, and can reduce the diameter of the outermost tube 1, and the cost of the outermost tube 1 can be reduced. The volume of the helium transfer tube can be reduced to shorten the evacuation time.</p> |
