The californium spectrum emitted by electrodeless lamps has been observed from 2320 to 28 600 Å (43 070 to 3495 cm<sup>−1</sup>) and the wavelengths of more than 13,000 lines measured. Energy-level analyses have yielded 136 even and 265 odd levels of Cf I and 40 even plus 172 odd levels of Cf II. The hyperfine width and the Landé g value are given for many levels. Twelve electron configurations have been identified for Cf I and four for Cf II. Observations of the hyperfine structures of <sup>249</sup>Cf and <sup>251</sup>Cf have confirmed the nuclear spins of 9/2 and ½ derived from nuclear decay systematics. The sign of the nuclear dipole moment has been determined to be negative for both isotopes. The lowest levels of some configurations of the elements Th through Es have been plotted versus the number of ƒ electrons for the neutral and the singly ionized species. A similar plot for three configurations of the neutral lanthanides and actinides gives a comparison of the electronic structures in these two series.
© 1995 Optical Society of America
John G. Conway, Earl F. Worden, and Jean Blaise, "Energy levels of neutral californium (249Cf I) and singly ionized californium (249Cf II)," J. Opt. Soc. Am. B 12, 1186-1202 (1995)