R-MATRIX ELECTRON-IMPACT EXCITATION OF Fe{sup 13+} AND ITS APPLICATION TO THE SOFT X-RAY AND EXTREME-ULTRAVIOLET SPECTROSCOPY OF CORONA-LIKE PLASMAS

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/190/2/322· OSTI ID:21454942

Liang, G Y; Badnell, N R ^[1]; Crespo Lopez-Urrutia, J R; Baumann, T M; Tawara, H; Ullrich, J ^[2]; Del Zanna, G ^[3]

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1. Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)
2. Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)
3. DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

Accurate excitation parameters are required to interpret the ultraviolet and X-ray spectra of Fe{sup 13+}. In this work, we use the AUTOSTRUCTURE code to describe the atomic structure of Fe{sup 13+}. The 197 lowest-lying fine-structure levels of the 3s{sup x} 3p{sup y} 3d{sup z} (x + y + z = 3), 3s {sup 2}4l, and 3s3p4{l_brace}s, p, and d{r_brace} configurations are included along with further correlation configurations: 3s3p4f, 3p{sup x} 3d{sup y} 4l (x + y = 2), 3l4l'4l'', and 3l3l'5l''. The resultant level energies, lifetimes of excited states, and oscillator strengths of transitions between these levels are assessed by comparison with available experimental data and previous calculations. Electron-impact excitation data among these lowest-lying levels are generated using the intermediate-coupling frame transformation R-matrix method. We assess the present results by comparisons with laboratory measurement for the excitation to the metastable level 3s {sup 2}3p {sup 2} P {sup o} {sub 3/2} and with available close-coupling calculations for other excitations. Using these data and a collisional-radiative model, we have analyzed soft X-ray and extreme-ultraviolet spectra from space satellite observations of a stellar corona and of solar flares, as well as measurements from an electron beam ion trap. We assess the contribution from Fe{sup 13+} emission lines in the solar and Procyon corona observations, and find and identify new lines in the X-ray region observed in the solar and Procyon coronae. The laboratory measurements also confirm that weak lines (218.177 A and 224.354 A) of Fe{sup 13+} contribute to the observed intensities in solar observations. The polarization effect due to the directional monoenergetic distribution of the electron energy has been taken into account in comparison with the laboratory measurements. Electron density diagnostics for the astrophysical plasma sources have been performed using the updated data so as to investigate their sensitivity to the atomic data source.

• OSTI ID: 21454942
• Journal Information: Astrophysical Journal, Supplement Series, Vol. 190, Issue 2; Other Information: DOI: 10.1088/0067-0049/190/2/322; ISSN 0067-0049
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
ELECTRON BEAMS
ELECTRON DENSITY
ELECTRONS
EXCITED STATES
EXTREME ULTRAVIOLET RADIATION
EXTREME ULTRAVIOLET SPECTRA
IRON IONS
MULTICHARGED IONS
OSCILLATOR STRENGTHS
PLASMA
R MATRIX
SOFT X RADIATION
SOLAR FLARES
SPECTROSCOPY
STARS
X-RAY SPECTRA
BEAMS
CHARGED PARTICLES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY LEVELS
FERMIONS
IONIZING RADIATIONS
IONS
LEPTON BEAMS
LEPTONS
MATRICES
PARTICLE BEAMS
PHYSICS
RADIATIONS
SOLAR ACTIVITY
SPECTRA
STELLAR ACTIVITY
STELLAR FLARES
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
X RADIATION