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

Abstract

A review of experimental and theoretical studies of the threshold photoionization of the heavier rare-gas atoms is presented, with particular emphasis on the autoionization resonances in the spectral region between the lowest two ionization thresholds (mp 5 2 P 3/2 and mp 5 2 P 1/2 , with m = 2, 3, 4, and 5 for Ne, Ar, Kr, and Xe, respectively). Observed trends in the positions, widths, and shapes of the autoionization resonances in dependence of the atomic number, the principal quantum number n, the orbital angular momentum quantum number and further quantum numbers such as K, J and F specifying the fine-and hyperfine-structure levels, are summarized and discussed in the light of ab initio and multichannel quantum defect theory calculations. The dependence of the photoionization spectra on the initially prepared neutral state, e.g. the 1 S 0 ground state, the mp 5 (m + 1)s 3 P 2 and mp 5 (m + 1)s 3 P 0 metastable levels and other states prepared from the ground or metastable levels in single-and multiphoton processes, are also discussed, including results on the photoionization of aligned and oriented samples and on photoelectron angular distributions. The effects of various approximations in the theoretical treatment of photoionization in these systems are analysed. The very large and at first sight discouraging diversity of observed phenomena and the numerous anomalies in spectral structures associated with the threshold ionization of the rare-gas atoms can be described in terms of a limited set of interactions and dynamical processes. Examples are provided illustrating characteristic aspects of the photoionization, and sets of recommended parameters describing the energy-level structure and photoionization dynamics of the rare-gas atoms are presented which were extracted in a critical analysis of the very large body of experimental and theoretical data available on these systems in the literature.

Impact of intense laser pulses on the autoionization dynamics of the 2s2p doubly excited state of He

“…The autoionizing states manifest themselves in the photoionization (photoabsorption) cross section as prominent features with vast diversity of resonant profile shapes (see, e.g., Ref. [6] for recent review on atomic autoionization).…”

How to Observe Coherent Electron Dynamics Directly

“…Excitation to the J ¼ 1 Rydberg states can be achieved via single-photon excitation or via a resonant multiphoton process with a J ¼ 0 intermediate state [17,34]. Figure 2 shows the proportional contribution of each of the five channels to the total wave packet as a function of time, via the probability P j;r>r c ðtÞ in Eq.…”

Extensive and accurate relativistic calculations of atomic data on the83Kr I spectrum

“…The other orbitals were treated as core ones. To first order correction by perturbation theory, the first order correction of ASFs (1) is written as a linear combination of all CSFs. These CSFs interact with the zero-order ASFs (0) , and thusly can be written as a linear combination of CSFs that are obtained via single excitation from occupied orbital of the reference configuration to the virtual orbitals.…”

“…Knowledge of reliable spectroscopic data in krypton spectra with which we are involved, is required in various fields of physics, such as astrophysics, determination of plasma composition, physics of lasers and photoionization processes [1][2][3]. These data include the energy levels, the oscillator strengths f , ij the radiative transition rates A , ij the Landé g-factors, the magnetic dipole and electric quadrupole hyperfine constants.…”