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.

2011 ◽  
Vol 89 (5) ◽  
pp. 551-570 ◽  
Author(s):  
A. Kramida
Keyword(s):  
Energy Levels ◽  
Experimental Studies ◽  
Theoretical Data ◽  
Theoretical Work ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Data Tables

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.

scholarly journals 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.

2011 ◽  
Vol 89 (4) ◽  
pp. 413-416 ◽  
Author(s):  
J. Bancroft Brown ◽  
M.S. Brown ◽  
S. Cheng ◽  
L.J. Curtis ◽  
D.G. Ellis ◽  
...  
Keyword(s):  
Branching Fractions ◽  
Energy Levels ◽  
Empirical Method ◽  
Oscillator Strengths ◽  
Intermediate Coupling ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Semi Empirical ◽  
Transition Array

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.

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.

2011 ◽  
Vol 89 (4) ◽  
pp. 403-412 ◽  
Author(s):  
Elmar Träbert ◽  
Yasuyuki Ishikawa ◽  
Juan A. Santana ◽  
Giulio Del Zanna
Keyword(s):  
Fine Structure ◽  
Ab Initio Calculations ◽  
Solar Corona ◽  
Ab Initio ◽  
Oscillator Strengths ◽  
Special Issue ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Cast Doubt

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.

On the interpretation of complex atomic spectra by means of the parametric Racah–Slater method and Cowan codes1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (4) ◽  
pp. 451-456 ◽  
Author(s):  
Jean-François Wyart
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Lanthanide Ions ◽  
Oscillator Strengths ◽  
Effective Parameters ◽  
International Colloquium ◽  
Atomic Spectra ◽  
Laboratory Plasmas ◽  
New Energy ◽  
Electronic Configurations

Theoretical studies of electronic configurations of several lanthanide ions in the Racah–Slater approach were performed with the standard suite of codes by R.D. Cowan, including a fitting of energy parameters. Configuration interaction was considered explicitly in the low configurations and was processed by effective parameters for doubly-excited far configurations. Mean errors lower than 100 cm–1 were obtained. Systematic differences are noticed between radial integrals calculated by ab initio PHFR and the Pfit fitted values. The consistency of the scaling factors SF(P) = Pfit/PHFR and of the effective parameters for far configuration effects is shown. In an application to Tm II, the predicted transition probabilities compared well with line intensities and led to the finding of new energy levels. In Nd II, the configuration 4f5 is identified.

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.

2011 ◽  
Vol 89 (4) ◽  
pp. 357-359
Author(s):  
B. Barbuy ◽  
C. Siqueira Mello ◽  
M. Spite ◽  
F. Spite ◽  
P. Bonifacio ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Oscillator Strengths ◽  
Heavy Elements ◽  
Special Issue ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Stable Elements ◽  
R Process

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.

The chemical composition of the sun1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (4) ◽  
pp. 327-331 ◽  
Author(s):  
N. Grevesse ◽  
M. Asplund ◽  
A.J. Sauval ◽  
P. Scott
Keyword(s):  
Chemical Elements ◽  
Molecular Data ◽  
Solar Neighborhood ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Solar Photosphere ◽  
International Colloquium ◽  
Laboratory Plasmas ◽  
Selection Of

We have very recently re-determined the abundances of nearly all the available chemical elements in the solar photosphere, from lithium to thorium (Asplund et al. Annu. Rev. Astron. Astrophys. 47, 481 (2009)). This new complete and homogeneous analysis results from a very careful selection of spectral lines of all the indicators of the abundances present in the solar photospheric spectrum, from a discussion of the atomic and molecular data, and from an analysis of these lines based on a new 3D model of the solar outer layers, taking non-LTE effects into account when possible. We present these new results, compare them with other recent solar data as well as with recent results for the solar neighborhood, and discuss some of their most important implications as well as some of the atomic data we still urgently need.

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.

2011 ◽  
Vol 89 (5) ◽  
pp. 639-645 ◽  
Author(s):  
Elmar Träbert ◽  
Joel Clementson ◽  
Peter Beiersdorfer ◽  
Juan A. Santana ◽  
Yasuyuki Ishikawa
Keyword(s):  
Electron Beam ◽  
Heavy Ions ◽  
Ion Trap ◽  
Oscillator Strengths ◽  
Valence Shell ◽  
Special Issue ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Electron Beam Ion Trap

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.

2011 ◽  
Vol 89 (5) ◽  
pp. 509-511 ◽  
Author(s):  
Peter Hakel
Keyword(s):  
Electron Distribution ◽  
Oscillator Strengths ◽  
Polarization Degree ◽  
Special Issue ◽  
Magnetic Sublevel ◽  
Energy Component ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Atomic Kinetics

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.

2011 ◽  
Vol 89 (5) ◽  
pp. 503-507 ◽  
Author(s):  
Christopher J. Bostock ◽  
Dmitry V. Fursa ◽  
I. Bray
Keyword(s):  
Electron Impact ◽  
Theoretical Calculations ◽  
Oscillator Strengths ◽  
Special Issue ◽  
Close Coupling ◽  
International Colloquium ◽  
X Ray ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Theory And Experiment

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.

Including all the lines1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (4) ◽  
pp. 417-428 ◽  
Author(s):  
Robert L. Kurucz
Keyword(s):  
Energy Levels ◽  
Model Atmosphere ◽  
Stellar Atmosphere ◽  
Oscillator Strengths ◽  
High Signal ◽  
Radiation Hydrodynamics ◽  
International Colloquium ◽  
Laboratory Plasmas ◽  
Laboratory Spectrum ◽  
Spectrum Synthesis

I present a progress report on including all the lines in the line lists, including all the lines in the opacities, and including all the lines in the model atmosphere and spectrum synthesis calculations. The increased opacity will improve stellar atmosphere, pulsation, stellar interior, asteroseismology, nova, supernova, and other radiation-hydrodynamics calculations. I also report on producing high-resolution, high-signal-to-noise atlases for use in verifying the line data and spectrum calculations, and as tools for extending laboratory spectrum analyses to higher energy levels. All the data are available on my web site: kurucz.harvard.edu .

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.

2011 ◽  
Vol 89 (4) ◽  
pp. 361-369
Author(s):  
Keith A. Olive
Keyword(s):  
Spectroscopic Data ◽  
Degrees Of Freedom ◽  
Oscillator Strengths ◽  
Fundamental Constants ◽  
Special Issue ◽  
International Colloquium ◽  
Atomic Spectra ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Constants Of Nature

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.

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