ENERGY-LEVELS OF NEUTRAL CALIFORNIUM (CF-249-I) AND SINGLY IONIZED CALIFORNIUM (CF-249-II)

The californium spectrum emitted by electrodeless lamps has been obser ved from 2320 to 28 600 Angstrom (43 070 to 3495 cm(-1)) and the wavel engths of more than 13,000 lines measured. Energy-level analyses have yielded 136 even and 265 odd levels of Of I and 40 even plus 172 odd l evels of Cf II. The hyperfine width and the Lande g value are given fo r many levels. Twelve electron configurations have been identified for Cf I and four for Cf II. Observations of the hyperfine structures of Cf-249 and Cf-251 have confirmed the nuclear spins of 9/2 and 1/2 deri ved from nuclear decay systematics. The sign of the nuclear dipole mom ent has been determined to be negative for both isotopes. The lowest l evels of some configurations of the elements Th through Es have been p lotted versus the number of f electrons for the neutral and the singly ionized species, A similar plot for three configurations of the neutr al lanthanides and actinides gives a comparison of the electronic stru ctures in these two series.