Superconducting bending magnets for the SR ring NIJI-III

A superconducting synchrotron radiation (SR) ring, called NIJI-III, was constructed. Immediately following the injection of electrons into NIJI-III, the maximum stored beam current was more than 400 mA. After the electrons of about 150 mA were routinely accelerated to their designed operating condition, the stored beam current was 100 mA at the beam energy of 600 MeV. This SR has four superconducting bending magnets. Each bending magnet has a bending radius of 0.5 m and a magnetic field strength of 4 T. These magnets are iron-free curvature dipole coils. The first magnet needed to be trained five times to reach the nominal current level and the next three magnets required less training. The applicability of these superconducting bending magnets for the SR ring has been demonstrated experimentally