The spectrum of singly ionized yttrium, Y II

Hollow-cathode spectra of yttrium have been registered in the wavelength region 1000-48 800 Å. Resonant charge transfer reactions in the light source favour the excitation of Y II, where 174 new levels have been established by means of 1284 newly classified lines. Altogether we report 1521 lines between 235 levels in Y II. The ground complex (4d + 5s)2 is now completely known and a number of Rydberg series have been extended. The new levels belong to the 4dnl (nl = 7s, 8s, 9s, 6p, 7p, 4d, 5d, 6d, 7d, 8d, 4f, 5f, 6f, 7f, 5g) and 5snl (nl = 7s, 8s, 6p, 6d, 4f, 5f) configurations. Eigenvector compositions, based on parametric calculations including configuration interaction, are given for all levels. The ionization limit has been determined to 98 590 ± 5 cm−1.