Mg 3pnd(J=3) autoionization spectra using isolated-core excitation

Abstract

The Mg 3pnd J =3 autoionizing spectra have been studied for n values ranging from 9 to 40, using an isolated-core excitation technique with ion detection. The measured spectra are found to be in generally excellent agreement with results from a calculated reaction matrix. The observed spectra exhibit strong interseries interactions between the 3pl/. nd;/2 and 3p&/2nd, series, and, for n 15, interferences between the amplitudes for excitation of the core electron to the 3P, /, and 3P3/2 ion states. Classifications of states for n «29 are tabulated. We discuss the difficulties in deducing autoionization rates for Mg from the experimental and theoretical data, the implications of which could have relevance to dielectronic recombination rate calculations.

Angular distributions of ejected electrons from autoionizing 3pndstates of magnesium

“…should in principle incorporate some longer-range multipole effects that were neglected beyond 12 a.u. in the previous E matrices [2,3].…”

“…, larger than the 12 a.u. box used for calculation of previous K matrices [2,3]. The new K Ls matrix also includes the 3png 'F3, 3png F3, and 3png 63 channels.…”

“…[2] and [3], the angular distribution measurements in Ref. [19] of the Mg 3pns J =1 states, and the angular distribution measurements of the Mg 3pnd J=1 and 3 states described in this paper form a progression of measurements that involve successively more and more complex sets of channels and wave functions.…”

“…The results of the alternate MQDT theory formulation using earlier K matrices of Refs. [2,3], described in the Appendix, are shown as a dotted line. Each horizontal line indicates the zero for the corresponding parameter that overlaps it.…”

Spatially Resolved Inter-electron Interaction of Autoionising States

“…This method, known as the isolated core excitation (ICE) method (Cooke et al 1978) has been used to gather a wealth of spectral information about doubly excited autoionising states of alkaline earth atoms (Sandner 1987). The essence of the ICE method is easily understood using Mg as an example (Dai et al 1990). Atoms are first excited to a bound Rydberg state, e.g.…”