Beam study with RF choppers in the MEBT of the J-PARC proton linac

A beam study of the RF fast chopper system in the MEBT of the J-PARC linac was successfully performed up to a beam current of 25 mA. The achieved rise/fall time of the chopped beam was about 10 ns. A beam signal during the chopper-on period, measured at the exit of the MEBT, was less than the noise level of the monitor systems. A flexible pattern of the chopped pulse train was achieved, which is useful for various kinds of operating pulse modes of the J-PARC accelerator.