Field Measurement of DC Magnets at 3-GeV RCS in J-PARC

The J-PARC RCS (Rapid Cycling Synchrotron) is designed to inject the ${\rm H}^{-}$ beam from the LINAC, to change their charge from ${\rm H}^{-}$ to ${\rm H}^{+}$, to accelerate the ${\rm H}^{+}$ beam from 400 MeV to 3 GeV, with $8.3\times 10^{13}$ protons per pulse at 25 Hz repetition rate, and to extract the ${\rm H}^{+}$ beam after the acceleration to the MLF (Material and Life Science Experimental Facility) and the MR (Main Ring). Thus the RCS has the beam circulating ring and three beam transport lines. The RCS ring consists of several magnets, and the DC magnets are installed for beam injection and extraction. The four steering magnets and two septum magnets are installed at injection line in order to adjust the beam injection point. One quadratic magnet, two steering magnet and two septum magnets are installed at dump line for the part of the beam with their charge not changed from ${\rm H}^{-}$ to ${\rm H}^{+}$ at the charge stripping foil. Two deflecting magnets to kick out the beam without exciting the pulse kicker magnets and three septum magnets are installed at the extraction line.