Development of a forced-cooled superconducting coil

A 10 kA forced-cooled D-shaped superconducting coil made of a cable-in-conduit type Nb3Sn conductor with a bore of 0.71m x 0.87m has been developed and the performance test was carried out. The experimental result showed that the coil was operated very stably up to 10 kA under the background field of 7 T. Also a quench transient analysis code, which includes mass, momentum and energy balance equations for supercritical helium, and energy balance equations for the conductor, has been developed to get a good understanding of the coil stability. The stability margin as a function of the current, which is evaluated from the analysis code, is in agreement with the experimental results. (author)