[31.20] Cataloguing Diagnostic Spectral Lines in the Extreme Ultraviolet

AAS 206th Meeting, 29 May - 2 June 2005
Session 31 Highlights in Laboratory Astrophysics
Topical Session, Wednesday, 8:30-10:00am, 10:45am-12:30pm, 2:30-4:00pm, 4:15-6:00pm, June 1, 2005, 102 D

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[31.20] Cataloguing Diagnostic Spectral Lines in the Extreme Ultraviolet

P. Beiersdorfer (Lawrence Livermore National Laboratory)

At the Livermore electron beam ion trap facility, we have been carrying out a systematic effort to identify and catalog the emission lines of the intermediate charge states of coronally abundant ions. Our measurements focus on the emission in the extreme ultraviolet and approximately cover the 20 to 200 Å wavelength band. Close to a thousand emission lines from O, Ne, Mg, Al, Si, S, Ar, and Fe ions with charge as low as O²⁺ and Mg²⁺ and as high as Fe²³⁺ have been measured so far at densities of near 10¹¹ cm^-3. The density-sensitivity of several lines has been demonstrated, and we have discovered the first X-ray diagnostic for magnetic field strength. Moreover, measurements of the K-shell ionization of O have shown that non-standard, sophisticated atomic models are needed to describe line formation processes and the observed spectra.

This work was supported by NASA's Astronomy and Physics Research Program award NNH04AA751 and performed under the auspices of the DOE by UC-LLNL under Contract W-7405-Eng-48.

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