| 摘要 |
<p>PURPOSE:To remarkedly reduce the amount of intrusion of heat into the inner tank container from the normal temperature outside and to lessen the amount of evaporation of liquid helium by a method wherein the operating line part is constituted of such a good conductor whose coefficient of thermal conductivity gets smaller with decreasing temperatures. CONSTITUTION:When an exciting operation and a demagnetizing operation are conducted, the operating lines 7a-7c constituting an operating line part 7 are led out to the normal temperature outside through an operating line piping 11 penetrating the outer tank container 14 of the vacuum tank and are connected to a power source 6. Therefore, the operating line piping 11 is thermally connected to a heat-shielding plate 12 through a thermal anchor 13 in an outer tank container 14. Accordingly, the heat which comes intruding into the interior through the operating lines 7a-7c of the operating line part 7 and the operating line piping 11 is transferred to the heat-shielding plate 12, and is absorbed in the heat-shielding plate 12, By this constitution, the external heat transferred to liquid helium 3 in an inner tank container 1 through the operating line part 7 and the operating line piping 11 can be prevented, and the amount of evaporation of the liquid helium 3 in the inner tank container 1 can be lessened.</p> |
