Development of superconducting magnets for beam lines and accelerator at KEK

Recent rapid development of superconducting magnets at KEK is reported. KEK is now constructing a superconducting pion beam line at the 12GeV Proton Synchrotron. A large bore superconducting dipole and a superconducting septum magnet for the beam line have been manufactured and successfully tested. Concurrently KEK is developing big aperture superconducting accelerator magnet of warm iron and warm bore. The first 1m model dipole of coil I.D. 14cm has been assembled and tested. A dipole field of 5.1 Tesla has been obtained in the second cool down test. This is a test dipole for TRISTAN proton ring magnet. Development program of superconducting magnets at KEK is also presented.