Fabrication of Bi-2212/Ag magnets for high magnetic field applications

Bi-2212/Ag multifilamentary tapes show practical transport properties in hi gh magnetic field regions above 20T and 4.2K, where it is considered diffic ult to use metallic superconductors. In this paper, the recent progress of our development for the Bi-2212/Ag insert magnets will be presented. The Bi -2212/Ag stacked double pancake coils with a 45-150mm outer diameter, 15-65 mm inner diameter and 50-220mm in height have been fabricated and tested in various backup magnetic fields up to 20T at the Tsukuba Magnet Laboratory of NRIM. A high resolution X-ray CT apparatus was used to observe a cross s ection of the magnet nondestructively, The transport properties of the magn ets are discussed in relation to the defects of the coil identified by this X-ray CT observation.