BEAM COMMISSIONING RESULTS OF THE RCS INJECTION AND EXTRACTION AT J-PARC

The beam commissioning of J-PARC (Japan proton ac-celerator research complex) 3 GeV RCS (rapid cycling syn-chrotron) has been started from the end of year 2007 and is in progress. As usual, injection is in the very first stage and strongly related to the other part of RCS commission-ing including the extraction, where an extracted beam fi-nally reflects the overall commissioning result. Starting with so-called center injection in the beginning, design op-eration, so-called painting injection study has already been started from the last run. This paper reports the summary of RCS injection and extraction beam commissioning results achieved so far