Measurements and data-based predictions for Delta n=1 resonance and intercombination transitions in the Be and Ne sequences

On Atomic Lifetimes and Environmental Density

Atomic lifetime measurements span a wide range, from attoseconds to years. The frontier of exploratory lifetime measurements, presently, is in the long part of the above time range, with an eye on astrophysical problems. In a combination of review paper, tutorial, and Editorial, the physical environments and experiments are discussed, in which the results of such lifetime measurements matter. Although accurate lifetime measurement results are important for our understanding of atomic structure and dynamics, and for the diagnostics of various plasma environments, the order of magnitude is often precise enough to see why time resolution may be of interest in an experiment, from laser-produced plasmas of high densities to planetary nebulae of very low densities.

Extreme-Ultraviolet Beam-Foil Spectra of Na through Cl

Beam-foil EUV spectra of elements from Na through Cl are presented, partly in survey spectra and partly in detail spectra. The ionization stages of interest are medium to high, so that three to thirteen electrons remain. Research topics are outlined and the problems of the measurement technique discussed.