Series in the Spectra of Aluminum and Magnesium in the Extreme Ultra-Violet

Abstract

PASCHEN (Ann. d. Phy. 71, p. 152, 1923), in his investigation of the spectrum of doubly ionised aluminum (Al. III.), and Fowler (“Series in Line Spectra,” p. 120), in his study of ionised magnesium (Mg. II.), have pointed out the type of series relations which exist in these substances, and have arranged many lines to conform to them. In a study 01 the spectra of both aluminum and magnesium in the extreme ultra-violet, under various forms of excitation, I have recently observed certain lines which appear to be higher members of some of the series discovered by Paschen and by Fowler ; Millikan has already identified the two strongest, but the remainder seem to have escaped observation. The wave-lengths and the series to which these lines belong are given in the following tables.