Status report on the 12 T split coil test facility SULTAN [for NET magnets]

The third phase of upgrading of the superconductor test facility SULTAN into a split coil system (SULTAN III) is in progress. SULTAN III consists of two coil packages, each containing three concentrically mounted superconducting solenoids. Together they will produce a field of nearly 12 T between the two coil packages, inside a solenoid bore of 58 cm. The outermost 6 T coils have NbTi conductors, whereas the inner 9 T and 12 T coils are made of A-15 cables. All Nb₃Sn coils are manufactured by the react-and-wind technique. The split coil arrangement, in connection with a sophisticated sample insert containing a 50 kA superconducting transformer, will allow testing of short samples of high-current-carrying superconductors, e.g. for fusion applications. The sample insert was designed to allow changing the samples within a few hours without warming up the whole magnet system. The authors discuss the present status and potential of SULTAN III