Additions to Certain Spectra of Sulphur, Potassium and Calcium

Abstract

Twenty-seven lines have been classified in S III. These locate six of the important singlet levels accurately with respect to the known triplets. S VI has been completely revised. Fourteen new terms have been added which classify eighteen new lines. The revised ionization potential is 87.610±0.003 volts. Two new singlet terms with intercombinations have been found in K VI and Ca VII. One new singlet term has been added to K IV and three terms to S VIII. Several of these last few spectra have been investigated in order to test the conclusions drawn from the previous paper in this issue of the Physical Review.