X-ray spectra of Ne-like Ba, La, Ce, and Pr ions

The spectra of Ne-like ions of Ba, La, Ce, and Pr in the 1.9 – 2.7 Å region, excited in the low-inductance vacuum spark plasma, have been obtained for the first time. A Johann's crystal spectrograph in combination with an image intensifier was used for recording the spectra. The 2s22p6 – 2s2p63p and 2s22p6 – 2s22p53d transitions have been identified in these ions along with the satellite lines of Na-like and Mg-like Ba–Pr ions.