Photoionization dynamics of excited Ne , Ar , Kr , 2 and Xe atoms near threshold

A review of experimental and theoretical studies of the threshold 11 photoionization of the heavier rare-gas atoms is presented, with particular emphasis on 12 the autoionization resonances in the spectral region between the lowest two ionization 13 thresholds (mp P3/2 and mp P1/2, with m = 2, 3, 4, and 5 for Ne, Ar, Kr, 14 and Xe, respectively). Observed trends in the positions, widths, and shapes of the 15 autoionization resonances in dependence of the atomic number, the principal quantum 16 number n, the orbital angular momentum quantum number ` and further quantum 17 numbers such as K, J and F specifying the fineand hyperfine-structure levels, 18 are summarized and discussed in the light of ab initio and multichannel quantum 19 defect theory calculations. The dependence of the photoionization spectra on the 20 initially prepared neutral state, e.g. the S0 ground state, the mp (m + 1)s P2 and 21 mp (m + 1)s′ P0 metastable levels and other states prepared from the ground or 22 metastable levels in singleand multiphoton processes, are also discussed, including 23 results on the photoionization of aligned and oriented samples and on photoelectron 24 angular distributions. The effects of various approximations in the theoretical 25 treatment of photoionization in these systems are analysed. The very large and at 26 first sight discouraging diversity of observed phenomena and the numerous anomalies in 27 spectral structures associated with the threshold ionization of the rare-gas atoms can be 28 described in terms of a limited set of interactions and dynamical processes. Examples 29 are provided illustrating characteristic aspects of the photoionization, and sets of 30 recommended parameters describing the energy-level structure and photoionization 31 dynamics of the rare-gas atoms are presented which were extracted in a critical analysis 32 of the very large body of experimental and theoretical data available on these systems 33 in the literature. 34 Photoionization dynamics of rare-gas atoms 2 (Version of 6 November 2011) 35