H.O. Di Rocco

Revised and extended analysis of the low configurations in Kr iii

The spectrum of doubly ionized krypton (Kr iii) was studied in the 430–8200-A range. Approximately 140 new Kr iii lines were classified as transitions between levels of the 4s24p4, 4s4p5, 4s24p34d, 5s, and 5p configurations, and approximately 150 were reclassified. The energy-level system reported for these configurations by Moore [ Natl. Bur. Stand. Circ.467 ( 1957)] was revised and extended to include three new levels of the 4s24p34d configuration and one level of the 4s24p35p configuration.

Line shifts of singly ionized xenon in high current pinched discharges

Abstract A study of Xe II line shifts originating in a discharge tube crossed by a high current, generally employed for producing laser action, is presented. By using a simple collisional model, our analysis shows that such shifts can be assigned to the microscopic Stark effect. The values of density and electron temperature, necessary for estimating collision parameters, have been determined by Papayoanou et al. in an independent series of measures under experimental conditions similar to our own.

Photorecombination to excited states of Xe in laser produced plasmas

Abstract In the present work, we report the frequency spectra of the continuum generated in a laser produced plasma of Xe, in the region 3000–5800 A. From these studies it can be concluded that we have identified the photorecombination thresholds (radiative recombination, RR) to the excited levels of Xe I and Xe II and some autoionizing resonances nl−El′ transitions where with nl we label bound levels and with El′ auto-ionizing levels are indicated.

The measurements of transition probabilities using pulsed capillary discharges

Abstract A pulsed capillary discharge is appropriate to obtain spectra of a high degree of ionization. Also, it could be useful for measuring the relative transition probabilities of these lines. In this paper we analyse the uncertainties due to a lack of local thermodynamic equilibrium and optical depths ratio, considering a two-level model. The experimental ranges of electron density and temperature are useful for obtaining good relative f values when using such a source, are analysed. This question is of greater importance when such fs are noticeably different.

Relations between observable parameters of collisionally broadened emission lines of rotating stars: a useful plot

This paper emphasizes the importance of spectroscopy techniques and the need of additional assumptions in analyzing stellar spectra, when experimental data are mapped in terms of a few parameters. Collisionally broadened profiles of emission lines originated in circumstellar material surrounding rotating stars are analyzed. Theoretical relationships between the ratio of the central flux intensity to the equivalent width of the emission line Fij,0/Wij, and the half-width at half of the maximum HWHMij are found. The plane shows general trends of the measurements and imposes bounds to the plasma parameters and the rotation velocities of the stars. With some educated guesses, it can be inferred whether the circumstellar material is spherically distributed or has a disc-like structure. As an example, an observational evaluation is made from data of gamma Cass.