New optics design of injection/fast extraction/abort lines of J-PARC main ring

The J-PARC Main Ring has three straight sections for injection, slow extraction and fast extraction. Injection line has been redesigned so as to give a higher reliability for the thin septa. The magnetic field can be reduced by adding an extra kicker. Alternative optics for the fast extraction with a larger acceptance has been proposed. In this design, the thin septa are replaced by kickers with a large aperture. Beam with an arbitrary energy can be aborted from opposite side from the fast extraction. An external abort line has been designed to deliver the beam aborted at an arbitrary energy to a dump just by using a static quadrupole doublet for the focus.