A LIQUID NEON CRYOSTAT FOR TESTING HIGH T-C MATERIALS

The present state of the art indicates that acceptable j-H characteris tics for power applications of the new high T-c superconductors will o nly be achieved using BSSCO materials operating at temperatures below about 40K. A boiling point of 27.1K and high specific cooling capacity make neon an eminently suitable choice of refrigerant at these temper atures. A cryostat is being constructed which employs a two stage Giff ord-McMahon cooler to liquefy neon gas and then maintain up to 5 litre s of liquid to be used either for 'in-situ' experiments or transfer to another cryostat.