STABILIZED HOLLOW ATOMS (IONS) PRODUCED WITH MULTIPLY-CHARGED IONS PASSED THROUGH MICROCAPILLARIES

Ions of 9 keV/u Ne9+ are impinged upon a microcapillary target along t he capillary axis. X-rays emitted from the projectile downstream of th e target show that a part of ions are in multiply excited states keepi ng a K-shell orbital open, i.e., hollow atoms (ions) are extracted in vacuum. Further, a considerable fraction of them are in extremely stab ilized states with lifetimes of similar to ns which is more than 10(6) times longer than typical lifetimes of a Ne K-hole. A theoretical pre diction suggests that core configurations with high spin multiplicitie s such as 1s2s2p P-4 are potential candidates of the stabilized fracti on.