Analyses of the XUV Spectra of K, Ca, Sc and Ti Isoelectronic with P I, Si I and Al I

An isoelectronic comparison of spectra in the P I, Si I and Al I sequences has been made for the elements K, Ca, Sc and Ti. In the course of this study we have also identified some lines in the spectra of adjacent elements in the same sequences, for example S IV, Ar IV, Ar V and Ar VI. In the P I and Si I sequences the study is restricted to transitions to the ground configurations 3 s 2 3 p 2 and 3 s 2 3 p 3 . In the Al I like spectra we have identified transitions between the configurations 3 s 2 3 p , 3 s 3 p 2 , 3 p 3 , 3 s 2 nd , 3 s 2 nf , 3 s 3 p 3 d and 3 s 3 p 4 s , where the nd and nf series have been traced to n = 6, and for nf in Ca VIII to n = 7.