Quartet system of C iv

Abstract

Theoretical and experimental investigations of the quartet system of C iv are reported. Twenty-seven quartet-state energies are calculated. Based on this work, several lines observed for the first time in the extreme-ultraviolet beam-foil spectra of carbon (10--200 nm) are classified as 1s2pnl ${}^{4}$L--1s2pn'l' ${}^{4}$L' and 1s2snl ${}^{4}$L--1s2sn'l' ${}^{4}$L' (n=2,3; n'=4,5) transitions. The calculated fine structures for the quartet states are also reported. In addition, a list of new observed lines classified in C iii and C iv is given.