Hyperfine structure investigations and identification of new energy levels in the ionic spectrum of147Pm

Hyperfine structure splittings have been measured for 75 lines of singly ionized promethium 147 Pm II with a hollow cathode discharge and a Fabry-Perot interferometer. Magnetic dipole and electric quadrupole splitting factors A and B have been determined for 10 levels of the 4f 5 6s configuration, 2 levels of 4f 5 5d, and 57 upper undesignated levels. The A-factors are in general agreement with calculated values. With the aid of Hartree-Fock calculations and Zeeman-effect data, four new levels of the 4f 5 ( 6 H)5d 7 K term were located. The strong lines terminating on these 7 K levels originate from levels of 4f 5 ( 6 H)6p 7 I, which were already known, but had not been designated. An unidentified line at 556.17 nm previously observed with collinear laser ion-beam spectroscopy is now classified as 4f 5 ( 6 H)5d 7 K 6 -4f 5 ( 6 H)6P 7 I 5 .