New spectroscopic data on high-lying excited even-parity levels of atomic neodymium

The two-color three-photon photoionization technique was used to obtain information on high-lying excited even-parity levels of atomic neodymium in the 32,100–35,300 cm−1 energy region. 417 even-parity levels, most of which were reported for the first time, were revealed. Out of these, 172 levels were assigned unique J values based on the J-momentum selection rule. The absolute accuracy of these levels was estimated to be better than ±0.2 cm−1.