| 摘要 |
PURPOSE:To eliminate the transfer of normal temperature external heat into an inner tank by composing voltage tap wirings of stainless steel wirings. CONSTITUTION:When a superconductive damage of a superconductive coil 2 occurs due to certain cause, the balance of the values of terminals 16a and 16b broken to generate a voltage, and if the voltage is the prescribed value or higher, it is judged as abnormal through a comparator 17 and a controller, not shown, and the coil 2 is deenergized. Since voltage tap wirings 10a-10c are composed of stainless steel wirings of very low thermal conductivity, the average thermal conductivity from the normal temperature out of an outer tank 4 to liquid helium temperature in an inner tank 1 becomes extremely low. Thus, the evaporation amount of the liquid helium generated by the invasion of heat can be reduced, and the tap wirings can be shortened. Accordingly, a measuring pipe can be shortened, and a cryogenic electric device such as a superconductive magnet unit can be simplified. |
