An intense spectrum of C I in the wavelength region from 1100 to 2000 Å has been recorded by the Naval Research Laboratory normal incidence spectrograph flown on Skylab. The source of the spectrum was a large solar flare. The spectral resolution was about 20000 at 1200 Å. We have identified 69 new lines of CI, and determined 63 new energy levels. The new lines arise from transitions from upper levels of high principal quantum number n where n ≳ 6. A list of 193 CI lines observed in the spectrum between 1140 and 1931 Å is presented, as well as calculated wavelengths for an additional 109 transitions between the new levels and the 2s2. 2p2. 3. P0, 1, 2 levels. The calculated lines fall between 1102 and 1140 Å and were not observed in the solar flare spectrum due to low instrumental efficiency at these wavelengths. The relative wavelength accuracy of most of the observed and calculated lines is about ±0.004 Å. The intensities of the C I lines are qualitatively compared with corresponding intensities in the laboratory spectrum.
© 1976 Optical Society of America
U. Feldman, C. M. Brown, G. A. Doschek, C. E. Moore, and F. D. Rosenberg, "XUV spectrum of C I observed from Skylab during a solar flare," J. Opt. Soc. Am. 66, 853-859 (1976)