Measurements and calculations of Zn-like heavy ions: an update1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

Previous observations of Zn-like ions of elements Yb (Z = 70) through U (Z = 92) in an electron beam ion trap differed (by value and by isoelectronic trend) from the (less precise) results of laser-produced plasma experiments and highlighted the need for much better calculations of ions with more than one electron in the valence shell. We review the progress since achieved and present new calculations for ions in the above range as well as EBIT observations of Zn-like Pt48+ ions (Z = 78). We identify accurate ab initio calculations that agree with the EBIT data as well as recent calculations that clearly fall short.

Polarization properties of the Ly-α line from sulphur plasmas driven by high-intensity, ultrashort-duration laser pulses1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

We report on a modeling study of the polarization properties of the Ly-α line in sulphur. The lower energy (J = 1/2) fine-structure component is unpolarized, while the polarization degree of the higher energy component (J = 3/2) can serve as a signature of an anisotropic electron distribution. We calculate the polarization degree of the J = 3/2 component with the help of a magnetic-sublevel population atomic kinetics model for plasma conditions that can arise in laser-produced plasma experiments. This demonstrates how observed polarization properties of the Ly-α could be connected with the characteristics of an anisotropic electron distribution.

Polarization of the Lyman-α1 X-ray line emitted by hydrogen-like Ti21+, Ar17+, and Fe25+ ions excited by electron impact1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

We present a review of the relativistic convergent close-coupling (RCCC) method and describe how it has been used to resolve the discrepancy between theory and experiment for the polarization of the Lyman-α1 X-ray line emitted by hydrogen-like Ti21+, Ar17+, and Fe25+ ions excited by electron impact. We find that taking account of Breit relativistic corrections is important to resolve the discrepancy between experiment and theoretical calculations.

Recent progress in spectroscopy of tungsten1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

This contribution reviews experimental and theoretical work on spectroscopy of tungsten published since the last critical compilation of the energy levels and spectral lines of highly ionized tungsten (Kramida and Shirai. At. Data Nucl. Data Tables, 95, 305 (2009)). Since then, 18 new experimental studies were published, which resulted in new identifications and (or) significantly improved wavelengths of spectral lines and energy levels of Li-like through As-like and Pm-like tungsten. A few tens of theoretical studies of tungsten spectra were published since 2008. A number of them report on high-precision calculations of energy levels, transition wavelengths, and radiative rates for tungsten spectra, such as neutral tungsten, Yb-like, Rh-like through Rb-like, Ag-like, Ga-like, Zn-like, Ni-like, Ca-like, Al-like, Mg-like, Na-like, Ne-like, B-like, Be-like, and Li-like. These developments are reviewed. Based on new experimental data, systematic errors are removed from some of the earlier measurements. Some new data are obtained by analyzing publications of other authors. Based on new published theoretical data, some old experimental results were confirmed and assessed. Revised and extended tables of energy levels and spectral lines of highly ionized tungsten are presented.

A visible spectral survey from the Alcator C-Mod tokamak1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

A visible spectral survey (3675–6744 Å) from the Alcator C-Mod tokamak has been performed using a high-resolution visible spectrometer constructed at the Lawrence Livermore National Laboratory. The Alcator C-Mod deuterium plasma is shown to have visible emission from numerous atomic species and low charge state ions including, D I, B II–III, B V, C II–III, N II–III, O II–IV, F II–III, Ne I, Na X, Al II–III, Si I–II, Cl II–III, Ar I–III, Ar X, Ti I and III, Fe I–III, Cu I, and III, Mo I, and W I. Nearly all of the emission is thought to come from the cooler edge of the plasma including the scrape-off layer, outside of the last closed magnetic flux surface. However, there is at least one example, included here, where intrinsic visible emission persists deeper into the plasma.

The 3s23p3d 3Fo term in the Si-like spectrum of Fe (Fe XIII)1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

The structure of Si-like ions is discussed for the example of iron (spectrum Fe XIII). The 3s23p3d 3Fo term with its three fine structure levels of very different lifetimes has eluded the early observations. Meanwhile, complementary experimental techniques have permitted to track these levels. Theory has also evolved from approximate techniques to accurate ab initio calculations, the results of which cast doubt on some earlier Fe XIII line identifications and guide the search for and the identification of the correct lines in solar corona spectra.

Lines of heavy elements and Fe ii in the UV of CS 31082-0011This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

The abundance of heavy r-elements may provide a better understanding of the r-process, and the determination of several reference r-elements should allow a better determination of a star's age. The space UV region (λ < 3000 Å) presents a large number of lines of the heavy elements, and in the case of some elements, such as Bi, Pt, Au, detectable lines are not available elsewhere. The extreme “r-process star” CS 31082–001 ([Fe/H] = –2.9) was observed in the space UV to determine abundances of the heaviest stable elements, using STIS on board Hubble Space Telescope.

Testing the variation of fundamental constants with astrophysical and spectroscopic data1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

In many theories of unified interactions, there are additional degrees of freedom that may allow for the variation of the fundamental constants of nature. I will review the motivation for and theoretical relations between such variations. I will then review the various astrophysical and experimental constraints on the variations of constants and their dependence on spectroscopic data.

Semi-empirical branching fractions of the 3s23p2–3s3p3 J = 2 transition array in P II1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

A semi-empirical method is used to characterize the 3s23p2–3s3p3 J = 2 transition array in P II. In this method Slater, spin–orbit, and radial parameters are fitted to experimental energy levels to obtain a description of the array in terms of LS-coupling basis vectors. The intermediate coupling (IC) and configuration interaction (CI) amplitudes so obtained are then used to predict the branching fractions of transitions within the array. These two configurations are particularly interesting because the 3s23p2 has been shown to be virtually free of CI, but affected by IC, whereas the 3s3p3 is virtually free of IC, but affected by CI.