Measurement of isotope shifts, fine and hyperfine structure splittings of the lithium D lines.

摘要

Precision measurement of the isotope shift as well as of the fine and hyperfine structure splittings of the Li D lines serve as stringent tests of theory. These measurements have been made previously using a variety of techniques including level crossing, optical double resonance, Fourier transform, frequency modulation, and laser atomic beam spectroscopy. Significant advances in the last decade have been made in theoretical modeling of few electron atoms and of neutral lithium in particular. However, the recent theoretical predictions disagree with the previous experimental data claiming the smallest uncertainties.;The lithium D lines were studied using a diode laser that excited an atomic beam. The laser frequency scan was calibrated using the known hyperfine splitting of the 7Li 2S1/2 ground state. The transmission of part of the laser beam through an etalon was monitored to correct for the nonlinearity of the laser frequency scan. Results for the 6,7Li isotope shifts, along with the fine and hyperfine structure splittings of the 2P1/2,3/2 states were determined and agree well with the latest theoretical values thus resolving the discrepancy with previous experimental data.