JPS56134785A - Super conductive device - Google Patents

Abstract

PURPOSE:To greatly decrease the conducting heat which is introduced in the device through leads by injecting liquid He in a heat insulating container for the current leads at the time of conduction thereby reducing generated Jule heat, and keeping the inside of the container at a vacuum state after the conduction. CONSTITUTION:A super conductive coil 6 and a terminal 12 are immersed in liquid He contained in a inner tank 3. Then a valve 14 is opened, the liquid He is injected in the heat insulating containers 9 and 9a for the current leads, and stabilized super conductive wires 11 and 11' are immersed. The evaporated gas in the container 9 passed through a path formed by spirally winding insulating coils 17 and 17' in the gap between pipes 18 and 18' and leads 8 and 8', cools the leads 8 and 8', and is recovered to the outside through a valve 16 and a pipe 15. After He 20 and 21 is injected, the coil 6 is conducted through the leads 8 and 8'. After the exitation, the coil is shorted by a permanent current switch, and the permanent current state is obtained. Thereafter He in the container 9 and 9a are extracted, the valve 14 is closed, the vacuum state is obtained by evacuation through the pipe 15, a valve 16 is closed, and the vacuum state is maintained. Since the intrusion of the heat is greatly reduced, the permanent current state is kept for a long time.