Glass capillary optics for focusing of high energy ion beams

Abstract

We have studied focusing of MeV He ion beams by fine glass capillary optics. The glass capillary optics are formed by using a puller as to have outlet diameters of sub-microns to several tens microns. The majority of incident ions are lost by the collision with the inner wall. However, impingent MeV ions to such insulating capillaries charge up the inner wall surface resulting in self-organized potential barrier. This electric field gently guides the ions through the capillary without significant energy loss. In this way a part of incident ions is focused and emitted through the outlet of the optics having the same diameter as the capillary outlet.