Operation of a Levitated Superconducting Ring in a Plasma Physics Experimental Device

An isolated, isochoric Dewar and superconducting ring, operable up to 130 000 ampere turns, has been installed in the Princeton Spherator, and plasma physics experiments have been performed with the ring levitated and stabilized by means of a system similar to that discussed previously. The evolution of this device has progressed through three stages. Initially the poloidal field coil was a conventional copper conductor ring within a vacuum jacket supported within the reaction chamber from top and bottom by four thin bars. In its second stage of development, the conventional coil was replaced by a superconducting coil and Dewar, supported by thin wire-like hangars. The present mode eliminates the need for mechanical supports of any sort.