Production and relaxation pathways of multiply excited states in slow highly charged ion-atom collisions

Abstract

We report triple-coincidence measurements of Auger electrons, scattered projectile, and target recoil ions in slow collisions of highly charged ions with many-electron atoms. Subpartial Auger-electron spectra corresponding to specific final projectile and recoil-ion charge states have been obtained by means of time-of-flight and position imaging techniques for the 60-keV O 7ϩ ϩAr collision system. The spectra exhibit marked differences and provide insights into the production and relaxation pathways of multiply excited states populated during the collisions. ͓S1050-2947͑99͒51105-0͔PACS number͑s͒: 34.70.ϩe, 34.50.Fa RAPID COMMUNICATIONS R3160PRA 59 H. MERABET et al.

Charge-exchange x-ray spectra: Evidence for significant contributions from radiative decays of doubly excited states

“…Predictions of classical overbarrier models [23,24] on multi-electron capture were generally found in fair agreement with experiment [13,14,[25][26][27][28][29][30]. They predict double capture to populate symmetric (n = n ′ ) or quasi-symmetric (n ≈ n ′ ) doubly excited states; widely believed to dominantly autoionize.…”

Doubly-Excited KLL States Formed in Triple Electron Capture

“…Projectile chargechange, recoil-ion production and total charge-transfer [1,2,3,4,7,8] cross sections were obtained for collisions of Ar q+ , I q+ and Xe q+ projectiles with various targets. The Auger electron spectroscopy was initially implemented in coincidence experiments with charge-state analyzed recoil ions [5,6] and then subsequently employed in time-of-flight (TOF) triple-coincidence with scattered projectile and target ions to study collisions of O 7+ and 15 N 7+ with Ar gas targets [7,8]. Although the investigation of multielectron capture has yielded a significant number of articles, experimental studies were primarily concentrated on low velocity collisions (v << 1 a.u.).…”