Spectroscopy of Argon Excited in an Electron Beam Ion Trap

Argon is one of the gases best investigated and most widely used in plasma discharge devices for a multitude of applications that range from wavelength reference standards to controlled fusion experiments. Reviewing atomic physics and spectroscopic problems in various ionization stages of Ar, the past use and future options of employing an electron beam ion trap (EBIT) for better and more complete Ar data in the x-ray, EUV and visible spectral ranges are discussed

Spectroscopy of ions using fast beams and ion traps

A knowledge of the spectra of ionized atoms is of importance in many fields. They can be studied in a wide variety of light sources. In recent years techniques coming under the broad heatings of fast beams and ion traps have been used extensively for such investigations. This article considers the advantages that various techniques have for particular applications

Isoelectronic trends of line strength data in the Li and Be isoelectronic sequences

The decays of the 2p J = 1/2 and J = 3/2 levels of Li-like ions and of the 2s2p {sup 1,3}P{sub 1}{sup 0} levels of Be-like ions can be used as simple-atom test beds for experimental lifetime measurements and for the development of accurate calculations of the transition rates. They have summarized and filtered the experimental data in order to obtain consistent data sets and isoelectronic trends that can be compared to theoretical predictions. The graphical presentation of line strength data enables direct comparison and evaluation of the merit of data along extended isoelectronic sequences. From this, the precision that is necessary in future meaningful experiments can be deduced

Magnetic-Field Sensitive Line Ratios in EUV and Soft X-ray Spectra

We discovered a class of lines that are sensitive to the strength of the ambient magnetic field, and present a measurement of such a line in Ar IX near 49 A. Calculations show that the magnitude of field strengths that can be measured ranges from a few hundred gauss to several tens of kilogauss depending on the particular ion emitting the line

Electric-dipole 5s - 5p Transitions in Promethiumlike Ions

The 5s-5p electric-dipole resonance transitions in highly ionized promethiumlike ions have been studied applying relativistic multi-reference Moeller-Plesset second-order perturbation theory. The transition wavelengths are determined to within 0.2 {angstrom} in the more highly charged ions, where the level degeneracies are small. For somewhat lighter ions a very large reference space was used in order to account for the many degeneracies. In order to calculate transition probabilities and lifetimes, correlation corrections have been added to the transition operator in the next order. The contributions from the higher orders of the theory, that is, frequency-dependent Breit correction, Lamb shift, and mass shifts, have been estimated. The results are used to re-assess spectroscopic data from beam-foil, electron beam ion trap, and tokamak observations

Observation of hyperfine mixing in measurements of a magnetic octupole decay in isotopically pure nickel-like 129Xe and 132Xe ions

We present measurements of high statistical significance of the rate of the magnetic octupole (M3) decay in nickel-like ions of isotopically pure {sup 129}Xe and {sup 132}Xe. On {sup 132}Xe, an isotope with zero nuclear spin and therefore without hyperfine structure, the lifetime of the metastable level was established as (15.06 {+-} 0.24) ms. On {sup 129}Xe, an additional fast (2.7 {+-} 0.1 ms) decay component was established that represents hyperfine mixing with a level that decays by electric quadrupole (E2) radiation

Relativistic multireference many-body perturbation theory calculations on Au64+ - Au69+ ions

Many-body perturbation theory (MBPT) calculations are an adequate tool for the description of the structure of highly charged multi-electron ions and for the analysis of their spectra. They demonstrate this by way of a re-investigation of n=3, {Delta}n=0 transitions in the EUV spectra of Na-, Mg-, Al-like, and Si-like ions of Au that have been obtained previously by heavy-ion accelerator based beam-foil spectroscopy. They discuss the evidence and propose several revisions on the basis of the multi-reference many-body perturbation theory calculations of Ne- through P-like ions of Au

Prominent Soft X-ray Lines of Sr-like Au41+ in Low-energy EBIT Spectrum

Relativistic multireference M{o}ller-Plesset perturbation theory has been employed to calculate with high accuracy the energy levels and transition probabilities of Cu- to Sr-like gold ions. The many-body calculations were carried out to identify the unassigned blended lines in the 35-40 angstroms region of the low-energy EBIT spectrum of the gold ions. Most of the prominent lines in the 35-40 angstroms region were identified as the emission lines in Sr-like gold