First test operation of 40 tesla class hybrid magnet system

We have completed the fabrication of a 40 T class hybrid magnet system including a 15 MW dc power supply, a 15 MW water-cooling system, a helium liquefier/refrigerator, and a hybrid magnet composed of an outer superconducting magnet and an inner water-cooled magnet. We are now beginning to test the system; this paper describes the first results. The outer superconducting magnet is designed to be cryogenically stable at 4.2 K and to generate background fields up to 15 T in a room temperature bore of 400 mm. The maximum operating current and the maximum stored energy are 1476 Å and 63.3 MJ, respectively. So far, we have tested the superconducting magnet to 14.2 T without quenching. We have fabricated two kinds of inner water-cooled magnets (Insert A and Insert B), which are designed to generate additional fields up to 25 T and 20 T in clear bores of 30 mm and 50 mm, respectively, in a background field of 15 T. We have tested the hybrid magnet system to 32.1 T using Insert B, and to 35.7 T using Insert A