Mit 12 Tesla Coil Experimental Results

The MIT 12 tesla coil was fabricated using a 486-strand bronze-matrix Nb₃Sn, JBK- 75 superalloy sheathed Internally Cooled Cabled Superconductor (ICCS). The rectangularly shaped ICCS conductor was wound into three double pancakes prior to a six-day reaction (4 days at 700 C followed by 2 days at 730 C). Prior to installation in the High Field Test Facility (HFTF) at LLNL the three subcoils were insulated and epoxy potted. With the HFTF providing a 9 T background field, the test coil was used to raise the central field up to 12 T. Measurements of critical current are reported for fields in the 11 to 12 T range for temperatures of 4.2, 5.2 and 7.5 K with supercritical as well as 1 atm, two-phase internal helium. Steady-state, inductively heated as well as quench induced operations are described.