Further investigations of the spectrrum of ionised nitrogen (N II)

Abstract

In a previous paper on the spectrum of ionised nitrogen (N II), the triplet and singlet terms based on the 2 p 2 P term of N III were dealt with. Mention was also made of a second group of terms, and quintet terms. Three of the deepest of these triplet terms were found by Bowen, namely, 2 p ' 3 S, 2 p 3 P and 2 p ' 3 D in the notation here adopted. The first part of the present paper deals with the identification of some of the quintet terms of this second group. The second part refers to some additional combinations arising from triplet terms of the first group. For completeness, a brief account of some singlet identifications by W. E. Pretty has been included. Three multiplets, previously suggested as being due to double electron transitions in the triplet system, have now been found (following a suggestion by Prof. H. N. Russell) to belong to the quintet system.