The spectrum of argon, krypton, and xenon excited by a repetitive condenser discharge method has been studied in the near infra-red region. The use of this method of excitation and a large infra-red spectrograph using a lead sulfide detector reveals about 170 new lines in these gases. About three-fourths of the lines are classified by known terms of the normal atom.
Some anomalies of spectra excited by the repetitive condenser discharge method are mentioned.
W. R. SITTNER and E. R. PECK, "The Spectra of Argon, Krypton, and Xenon between 1.2 and 2.2 Microns," J. Opt. Soc. Am. 39, 474-477 (1949)