STABILITY MEASUREMENTS ON A 1-T HIGH-TEMPERATURE SUPERCONDUCTING MAGNET

A high temperature superconducting magnet based on Bi-2223 conductor w as built at the American Superconductor Corporation. The magnet was co nstructed by a react and wind technique using conductors made from a m etallic precursor process. It has a winding ID of 25.4 mm, OD of 87.6 mm, and height of 107.3 mm. A heater, two thermometers, and several vo ltage taps were built into the high field region of the magnet for sta bility measurements. The magnet generates 1.1 T central field at 4.2 K when operating at 1 mu V/cm over the entire conductor length, includi ng all the joints. Stability measurements were performed in background fields up to 2.5 T from 4.2 K to 77 K. Stability margins more than 2 orders of magnitude higher than a low temperature superconductor were observed.