Abstract

Time-resolved spectroscopic measurements have been made of absolute intensities, spectral profiles, and self-absorption for He i lines in the early helium afterglow. Population densities are calculated for the excited states, including metastable states, as a function of time. Electron densities, electron temperatures, and Doppler temperatures are derived from the data. Similar emission and self-absorption measurements of He₂ spectra indicate an increase in molecular populations during the early afterglow. An interpretation identifies the ³S₁ atomic metastables as a source of continued ionization and heating of the plasma and a participant in the formation of metastable helium molecules.

© 1965 Optical Society of America

Spectroscopic Study of the Early Afterglow in Helium: Visible Bands and Hopfield Continuum*

Don Villarejo, Ronald R. Herm, and Mark G. Inghram
J. Opt. Soc. Am. 56(11) 1574-1584 (1966)

Time variation of the concentration of helium metastable atoms in He-Kr⁺ ion laser

Isamu Kato, Akira Iwasaki, Akifumi Yonehara, and Tsukasa Shimizu
J. Opt. Soc. Am. 69(1) 175-177 (1979)

Spectrographic Study of the Afterglow of Mercury*

Edward E. Stepp and Richard A. Anderson
J. Opt. Soc. Am. 55(1) 31-33 (1965)

Mechanism of the Short-Duration Nitrogen Afterglow

O. Oldenberg
J. Opt. Soc. Am. 61(8) 1092-1098 (1971)

Afterglow Spectrum of a rf Mercury Discharge*

James A. Aubrecht, Bruce M. Whitcomb, Richard A. Anderson, and Robert C. Pickett
J. Opt. Soc. Am. 58(2) 196-203 (1968)