X-ray measurements of highly charged Ar ions passing through a Ni microcapillary: Coincidence of L X-rays and final charge states

We have made coincidence measurements between L X-rays and final charge states of highly-charged Ar ions passing through a Ni microcapillary thin foil to study the formation and relaxation processes of hollow atoms. By using N6+ projectile ions which have single K-shell hole, Ninomiya et al. [Phys. Rev. Lett. 78 (1997) 4557] showed the existence of long lived excited states formed by multiple electron transfer from a Ni microcapillary thin foil. To further study the formation and relaxation dynamics, such experiments were extended to Ar ions with multiple L-shell holes. The yields of L X-rays from Ar ions, which have one stabilized-electron, decrease faster than those from ions with multiple stabilized-electrons, when the projectiles have multiple inner shell holes.