Auger decay of the photoexcited1s−1npRydberg series in neon

Abstract

Photoionization of the rare gases has provided a convenient testing ground for atomic many-body theory due to the wealth of experimental measurements available @1‐3#. Among the various methods at the forefront of theoretical photoionization studies are those based on the close-coupling expansion @4#, for instance, the widely used R-matrix method @3,5#. In this approach, the scattering wave function is necessarily expanded in terms of a finite basis. Most photoionization studies using close-coupling methods have focused on outer-shell processes, due to restrictions on the size of the basis set. An excited state with a hole in an inner shell can often decay into an infinite number of open channels via Auger decay, and all of these channels cannot be included within an explicit close-coupling expansion. The purpose of the present study is to treat the resonance region in argon where there is a hole in the 2 p shell. We combine optical potential considerations and multichannel quantum defect theory ~MQDT!, within R-matrix calculations, to overcome the difficulties associated with the infinite number of open channels.