CONSTRUCTION AND CHARACTERIZATION OF AN INDUCTIVE SUPERCONDUCTING CURRENT LIMITING DEVICE BASED ON CERAMIC Y1BA2CU3O7-DELTA O-RINGS

Experimental results about the response of a small-scale superconducti ng inductive device as current limiter are reported. The device is bas ed on ring-shaped samples of bulk Y1Ba2Cu3O7-delta coupled to a primar y coil through a magnetic core. The samples were obtained by pressing into an O-ring shape Y1Ba2Cu3O7-delta powders, which reacted following the standard ceramic process. The size of the O-rings was 1 cm intern al diameter, 1.6 cm external diameter, and 0.3 cm height. The response of the device was measured at liquid nitrogen temperature as a functi on of the type of magnetic core, the critical current of each individu al superconducting O-ring, the number of O-rings used simultaneously, the frequency of the a.c. current and the number of turns of the prima ry coil. (C) 1997 Published by Elsevier Science Ltd.