Energy levels, with classifications and uncertainties, have been compiled for the spectra of the neutral atom and all positive ions of potassium (Z=19). Wavelengths with classifications, intensities, and transition probabilities are also tabulated. In addition, ground states and ionization energies are listed. For many ionization stages experimental data are available; however for those for which only theoretical calculations or fitted values exist, these are reported.

Wavelengths, Transition Probabilities, and Energy Levels for the Spectra of Potassium "K I through K XIX…

Energy level values, with designations and uncertainties, have been compiled for the spectra of the neutral atom and all positive ions of cesium (Z=55). Transition wavelengths with classifications, intensities, and transition probabilities are also tabulated. In addition, ground states, ionization energies, and hyperfine structure constants are listed. For most ionization stages experimental data are available; however, for those for which only theoretical calculations or fitted values exist, these are reported. There are a few ionization stages for which only a calculated ionization potential is available.

Wavelengths, Transition Probabilities, and Energy Levels for the Spectra of Cesium (CsI–CsLV)

We report the operation of a saturated 96.9-nm laser in Cs vapor that has an extrapolated small signal gain of exp(83) in a total length of 17 cm. We believe that lasing occurs from a core-excited level embedded in the continuum of the valence electron. The laser is pumped by soft x rays from a synchronous, traveling-wave, laser-produced (2.5-J, 20-ps, 1064-nm) plasma.

12.8-eV laser in neutral cesium.

Systematic calculations of energies and decay rates for the 2p53snl core-excited states (with n<or=7) in Na have been performed using a configuration-interaction method, including spin-orbit interaction and core-polarization correlation through a semi-empirical model core potential. Data obtained extend and clarify considerably the classification of lines in the existing photoabsorption and ejected-electron spectra of Na. Lifetime determination included radiative decay to the bound 2p6nl levels and to the lower core-excited states as well as autoionization. Both correlational and relativistic effects play an important role, as expected, but in addition it was found that the non-orthogonality of bound and continuum orbitals, being a result of core excitation, is also very important in evaluating of autoionization rates. The predicted lifetimes are analysed with respect to their 'quasimetastability', which has recently attracted great attention in atomic spectroscopy and in the construction of XUV lasers.

Energy levels and lifetimes for the 2p53snl core-excited states in Na

The paper reviews both the properties and the applications of core-excited metastable atoms. The production of these atoms by microwaves, pulsed hollow-cathode discharges, and laser-produced x rays is described. We discuss the application of these atoms to several new types of spectroscopy that allow autoionizing linewidths as narrow as 0.1 cm−1 to be measured. The application of these metastables to the generation of picosecond-time-scale soft-x-ray pulses and to XUV lasers is also discussed.

A. J. Mendelsohn

Papers

Emission spectra of quasimetastable levels of alkali-metal atoms.