INJECTION AND EXTRACTION ORBIT OF THE J-PARC MAIN RING

The J-PARCmain ring (MR) accelerates a high intensity proton beam and deliver to the neutrino experimental hall by the fast extraction and to the hadron experimental facility by the slow extraction. The 3 GeV beam from the rapid cycle synchrotron (RCS) is injected by the bunch to bucket transfer into the MR. The MR has two beam dumplines, the first one is used to dumpthe beam at an injection energy and the second one can be used for beam abort. We summarize designs of injection and extraction orbits and discuss about beam apertures and the beam loss.