The production of high-duty-cycle, high-yield beams of highly charged ions with an electron beam ion source

Abstract

High yields of highly charged ions are produced with electron beam ion sources (EBISs) operated in a batch or pulsed mode, yielding small duty cycles. An EBIS operated in a continuous, dc, or leaky mode can produce continuous, ‘‘dc’’ ion beams, although with substantially lower yields especially for the higher charge states. This article introduces the leaky batch mode and the dc batch mode of operation which combine the high duty cycles obtained with leaky or dc modes with the high yields of highly charged ions obtained with batch modes. The leaky batch mode produces ion beams with duty cycles as high as 90% with ion yields as high as 70% of the most efficient batch mode. The dc batch mode delivers constant intensity (dc) ion beams during 50% of the time with ion yields as high as 98% of the most efficient batch mode. When the dc batch mode is combined with the stretcher mode proposed by Becker, the dc batch mode will allow for dc ion beams of constant intensity with yields close to the most efficient batch mode.