Inner-shell photoionization of excited lithium

Abstract

Calculations of inner-shell photoionization of 1s 2 2p 2 P o and 1s 2 3p 2 P o Li excited states have been performed using recent developments of the R-matrix code with a 29-term target representation for incident photon energies up to 165 eV, with particular emphasis on multiple electron processes. Partial and total cross sections are given for a number of excitation processes including the lower members of 19 hollow atom resonance series. The results are compared with recent experimental measurements of the lowest 2s2p 2 2 L e resonance of even-parity hollow lithium states produced by photoexcitation of laser-excited lithium atoms. Experiment and theory are in excellent agreement on a relative scale. The enhancement of the shake-up process increases with initial state excitation, up to 500% over that of the ground state for 1s 2 3p 2 P o . Good agreement is also obtained for K-shell photoionization when comparing branching ratios with available experimental results.

Photoionization of laser-excited caesium atoms above the 4d ionization threshold

“…Alkali metals are however very reactive, thus the target densities have to be kept relatively low in order to avoid contamination of the experimental setup. High resolution studies were started only in the last 15 years or so with the advent of third generation light sources which provide a sufficiently high flux to offset the low target concentration [4,5,6,7]. Theoretically alkali metals are appealing, because of their hydrogen-like electronic structure with only one electron in an s-orbital outside a noble gas closed shell configuration.…”

Combination of lasers and synchrotron radiation in studies of atomic photoionization

“…9) is well described by the theoretical models using the R-matrix calculations [20]. The first calculations based on MCHF calculations reproduced perfectly the general trend [18], i.e.…”

“…These satellite lines are commonly divided into SU transitions (D' ¼ 0) and CSU or interchannel coupling satellites (D'a0) [2,21]. While for the first a simple model, based on the spatial overlap of the electronic wavefunction in the neutral and the ionized atoms, can be used to obtain the relative intensities of the lines, the adequate description of the CSU satellites requires more sophisticated theoretical approaches [20,45].…”

“…The measured oscillator strengths for resonant excitations from the excited state, for relative photoionization cross-sections and branching ratios of different photoionization channels provided a thorough basis for theoretical approaches, which aim to describe the dominant contribution of the complex many-body interactions governing the photoionization of laser-excited atoms (e.g. [17][18][19][20]). …”

Quantum-number dimensional-scaling analysis for excited states of multielectron atoms

“…This method can be extended to include relativistic effects for nuclei with high Z numbers by including the kinetic-energy mass correction term of the Breit-Pauli Hamltonian. [19] f Reference [20] g Reference [21] h Reference [22] TABLE V: Ground state and various excited states of beryllium. Core electrons 1s 2 are implicit in the notation.…”