Reinvestigation of some of the autoionizing levels in the spectrum of CuI

Abstract The emission spectrum of CuI was generated in a 10 A d.c. arc and photograped in the second and third orders of a 3.4m Jarrell-Ash spectrograph using a 1200 grooves/mm grating. The spectral lines involving the autoionizing levels 5 s ′ 4 D , 5 s ′ 2 D and 5 s ″ 2 D arising from the 3 d 9 4 s 5 s configuration have been reinvestigated to obtain comprehensive data on the half widths of all of the diffuse lines. The data on 5 s ″ 2 D 3 2 are reported for the first time. It was found that the half widths of the 5 s ′ 4 D 3 2 and D 3 2 lines are larger than those of the corresponding multiplet components 5 s ′ 4 D 3 2 and 2 D 3 2 whereas the half width of 5 s ″ 2 D 5 2 is larger than that of 5 s ″ 2 D 3 2 . The line profiles were fitted to Gaussian and Lorentzian distributions and it is shown that the contribution to the breadth of a sharp line is mainly from the instrumental width (Gaussian), whereas the anomalous broadening of the diffuse lines caused by autoionization is predominantly Lorentzian.