Fabrication and test a 600 kJ SMES model coil

A small SMES system and a 600 kJ SMES model coil were fabricated. High temperature superconducting (HTS) wire which was reinforced with stainless steel was used for winding the model coil and its critical current was 624 A at self-field and 20 K. The type of model coil is double pancake coil (DPC). The number of turns of a DPC is 282 and length of HTS wire per DPC is about 220 m. A two stage GM cryo-cooler (RDK-408) was used for cool down the SMES system and mounted in the middle of the top plate of a cryostat which has 580 mm outer diameter. Cooling plates for conduction cooling were placed on top and bottom of DPC. Operating temperature of the system is 20 K. Cryogenic temperature sensors (Cernox, SD type) were attached on the surface of a copper cylinder block for cool down test of the system. Temperature control test by a heat load also carried out.