Preliminary considerations and experiments to obtain higher brightness and pulsed ion beams with bunch

Summary form only given. One of the important issues concerning intense pulsed ion beams for inertial confinement fusion compared with lasers is to obtain higher ion beam brightness. It is hoped that bunching the beams during beam transport can be used to achieve still higher brightness of the beams. To bunch the beams, focusing-type ion diodes without turn-on delay times, large current channels to transport focused ion beams, and pulsed power generators to supply high voltage to the ion diodes are required. Accordingly, a pulsed ion source was operated with an active anode, and a small channel to be assembled together with the cryogenic ion diode was designed. The particle distributions within the ion diode, which had a substantial effect on the characteristics of the beam focusing and the beam transport, were measured. To extract ion beams without turn-on delay times and to exclude the disturbances from neutral particles, an advanced version of the active anode diode was developed. Plasma injected by a flashboard from behind the anode before the diode's main high-voltage pulse were used as the ion source