Design of a Multi-Element Corrector Magnet for the Storage Ring NewSUBARU

A design for a multi-element octupole-base corrector magnet is presented. The new corrector magnet will be installed in the electron storage ring NewSUBARU in place of vertical steering (skew dipole) magnets. The new magnet uses coil windings to produce the skew quadrupole, skew sextupole, normal octupole, and skew dipole fields. The skew dipole element is used to achieve vertical steering. The skew quadrupole and the skew sextupole elements are for the resonance correction. The normal octupole element is used to control the higher order dispersion function and the higher order momentum compaction factor. In this design the main coil is wound around the return yoke instead of the pole. We expect improvement of the beam lifetime and injection efficiency during normal operation as well as improved isochronism during extreme quasi-isochronous operation. In designing the magnet, careful consideration is given to field interference caused by a neighboring magnet, which is in close proximity to the corrector magnet. The magnetic field with field interference is calculated using OPERA-3D.