Hyperfine Structure of La1 in a Cathode Discharge Tube

Hyperfine structures of La1 are reported using Doppler-free intermodulated fluorescence, Doppler-limited laser induced fluorescence and optogalvanic spectroscopy in a home-made cathode discharge tube. The constants A and B for the levels at 20197.34, 21447.86cm^-1 and constant A for the levels at 19379.40, 18156.97, 94910.38, and 24409.68cm^-1 are reported. A homogeneous linewidth less than 40MHz and the different resolutions between fluorescence and optogalvanic spectroscopy were observed.