Stabilized Hollow Ions Extracted in Vacuum

Abstract

K x rays emitted from 2.1 keV/uN{sup 6+} ions passed through a thin Ni microcapillary foil were measured in coincidence with the exit charge states. Ions with a K hole but with several electrons in outershells, i.e., hollow ions formed above a surface (in the first generation), were successfully extracted in vacuum. It was found that a considerable fraction of extracted hollow ions had extremely long lifetimes of the order of ns. {copyright} {ital 1997} {ital The American Physical Society}