Charge transfer and ionization in low-energyArq++ Ne collisions

Multielectron processes in 10-keV/uArq+(5≤q≤17) on Ar collisions

“…7(a) -7(c) we show three examples which illustrate this evolution. We observe that all states belonging to the (4,4) manifold in Ar (core charge q =8}are energetically allowed to autoionize to the (3, m) continuum limits, and the same is true for a large fraction of such states in Ar' + (core charge q =14). However, none of these states are allowed to autoionize to the (3, oo) continuum limits in Ar' + (core charge q =16) and therefore the only available limits are (2, oo).…”

“…For example, for the same core charge q = 14 all the (4,4,4) in Ar"+ states are now energetically allowed to autoionize to the (3,4, oo) limits. Similar evolution is observed for the core q =16 where a large number of the (4,4,4) and (3,4,4) states can autoionize to the (3,4, oo) and (3, 3, oo) continuum limits. We have investigated this evolution for configurations representing electrons in the same and in different shells of doubly, triply, quadruply and quintuply excited states which were frequently predicted by the MCBM.…”

“…(a) Transitions involving electrons in the same shell proceed first since they generally have higher Auger rates than electrons in different shells. (b) If two or more transitions involving electrons in the same shell are possible, the one involving the more tightly bound electrons will proceed first [e.g., (4,4) will autoionize before (5,5)]. (c) If two or more transitions involving electrons in different shells are possible, the two electrons that spend more time in the vicinity of each other will autoionize first; otherwise the minimum ejected electron energy criterion is imposed and the two electrons giving rise to the lowest-energy continuum electron will autoionize first.…”

“…For example, in the configuration (3,4,4,5,6) the two electrons in (4,4) will undergo the first transition and the relevant energy levels and continuum limits are those of (3,4,4), (3,3, ao (3,n2~6) or (4, n2 8), for which the inner electron may stabilize via one or two photon emission processes, radiative stabilization of both electrons is assumed to take place. This situation is encountered when a highly excited electron is denied the opportunity to participate in an Auger process according to the previous rules.…”

The contribution ofK-electron capture for the production of highly charged Ne recoil ions by 156 MeV bromine impact

“…The multiple ionization process of the Ne recoils can be used as a tool to probe the impact parameter dependence of the Ne-K capture process, because the multiple Ne ionization peaks for different Ne charge states at different impact parameters. Several experiments measuring correlated charge state distributions of both collision partners have been performed recently [3][4][5][6][7][8][9][10][11]. We have measured projectile charge state dependent cross sections for the production of recoil ions in the collision system 156 MeV Br" + + Ne ~ ~ Br"' + + Ne q + +(n'-n+q)e , n=14, 27 with a projectile ionrecoil ion coincidence technique which made possible the simultaneous determination of the charge states of both collision partners.…”