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.

2011 ◽  
Vol 89 (5) ◽  
pp. 615-626 ◽  
Author(s):  
A.T. Graf ◽  
M.J. May ◽  
P. Beiersdorfer
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Oscillator Strengths ◽  
Visible Emission ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
To Come ◽  
Low Charge ◽  
Spectral Survey

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.

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.

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.

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.

K-shell spectroscopy of Au plasma generated with a short-pulse laser1This 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. 647-651 ◽  
Author(s):  
C. Zulick ◽  
F. Dollar ◽  
H. Chen ◽  
K. Falk ◽  
G. Gregori ◽  
...  
Keyword(s):  
Short Pulse ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Laser System ◽  
Oscillator Strengths ◽  
X Rays ◽  
Plasma Diagnostic ◽  
International Colloquium ◽  
X Ray ◽  
Population Distributions

The production of X-rays from electron transitions into K-shell vacancies (Kα,β) emission) is a well-known process in atomic physics and has been extensively studied as a plasma diagnostic in low- and mid-Z materials. However, X-ray spectra from near neutral high-Z ions are very complex, and their interpretation requires the use of state-of-the-art atomic calculations. In this experiment, the Titan laser system at Lawrence Livermore National Laboratory was used to deliver an approximately 350 J laser pulse, with a 10 ps duration and a wavelength of 1054 nm, to a gold (Au) target. A transparent bent quartz crystal spectrometer with a hard X-ray energy window, ranging from 17 to 102 keV, was used to measure the emission spectrum. Kα1,α2 and Kβ1,γ1 transitions were observed over a range of target sizes. Additionally, a series of shots were conducted with a pre-ionizing long pulse (3 ns, 1–10 J, 527 nm) on the backside of the target. FLYCHK, an atomic non-LTE code, designed to provide ionization and population distributions, was used to model the experiment. Kα/Kβ ratios were found to be in good agreement with the predicted value for room temperature Au targets.

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.

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.

Spectroscopic analysis and modeling of tungsten EBIT and Z-pinch plasma experiments1This 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. 599-608 ◽  
Author(s):  
G.C. Osborne ◽  
A.S. Safronova ◽  
V.L. Kantsyrev ◽  
U.I. Safronova ◽  
P. Beiersdorfer ◽  
...  
Keyword(s):  
Electron Beam ◽  
Charge State ◽  
Ion Trap ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Oscillator Strengths ◽  
Charge Balance ◽  
International Colloquium ◽  
Pinch Plasma ◽  
Z Pinch

Spectral tungsten data taken on an electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory are analyzed between 3 and 8 Å for electron beam energies between 2.5 and 4.1 keV. The advantage of using charge state balancing with the experimental EBIT spectra for the identification of lines is employed and discussed. Theoretical Hebrew University Lawrence Livermore Atomic Code (HULLAC) modeling is then benchmarked against the experimental EBIT results. In particular, Co-, Ni-, Zn-, Cu-, Ga-, and Ge-like transitions were modeled independently using HULLAC to aid in charge state balancing. This model is then compared with Z-pinch plasma data collected on Zebra, the 1.6 MA pulse power generator located in the Nevada Terawatt Facility at the University of Nevada, Reno. The model is used to calculate charge balance and average ionization levels of these experimental plasma results, with particular focus on planar tungsten arrays.

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.

Hyperfine quenching: review of experiment and theory1This 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. 429-437 ◽  
Author(s):  
W.R. Johnson
Keyword(s):  
Oscillator Strengths ◽  
Special Issue ◽  
International Colloquium ◽  
Atomic Spectra ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
Hyperfine Quenching ◽  
Theory And Experiment ◽  
Made In

We give a brief outline of the theory of hyperfine quenching followed by a review of the progress that has been made in both theory and experiment since the pioneering work of Garstang (J. Opt. Soc. Am. 52, 845 (1962)).

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