Cryogenfree high field superconducting magnets

A cryogenfree superconducting magnet (CSM) has been realized using Bi-system high temperature superconducting current leads. Although conventional low temperature superconducting magnets wound with NbTi and Nb/sub 3/Sn wires are utilized, liquid helium is no longer required for a magnet operation. Up to now, various kinds of cryogenfree superconducting magnets such as a high field 15 T-CSM, a large bore 5 T-CSM with a 300 mm room temperature bore, and a unique high field X-ray diffraction apparatus combined with a split-pair 5 T-CSM have been successfully developed. Moreover, a split-pair CSM for neutron scattering and a high temperature operation CSM at 20 K employing Ag-sheathed Bi2223 tape have been demonstrated. It is expected that the further rapid progress in a cryogenfree superconducting magnet will be made and high field applications will be enlarged in the near future.