RADIO-FREQUENCY BEAM CHOPPING IN A SURFACE-PLASMA-TYPE NEGATIVE-ION SOURCE

A direct fast-chopped beam extracted from a surface-plasma H- ion sour ce is proposed and a preliminary test has been examined. The converter bias voltage is modulated by rf pulses and the extracted H- beam is o bserved. The direct fast-chopped H- beam extracted from the ion source has a good response to the modulation of the converter bias voltage, as expected. The chopped H- beam extracted by this method has been inj ected into the 500 MeV booster synchrotron at KEK-PS. (C) 1996 America n Institute of Physics.