43rd Conference of The European Group on Atomic Systems (EGAS), Switzerland, 1 - 04 July 2011, pp.116
In a continuation of previous work done at the TU Graz [1], we have further investigated spectral lines of 5d-shell element lantanum. In the present work we aimed to determine magnetic dipole hyper ne interaction constant A for higher lying energy levels, to classify new spectral lines as well as to discover new ne structure energy levels of La I.
The measurements have been performed with laser-induced fluorescence spectroscopy using a tunable ring-dye laser pumped by Ar-ion laser. With the dyes Kiton-Red and Rhodamine 6G we cover the spectral range from 560 nm to 625 nm and form 710 nm to 745 nm, respectively. La atoms are produced by sputtering in a hollow cathode discharge.
The hyperfine structure has been analyzed for 73 new spectral lines of La I, which are not listed in Meggers [2] and MIT [3] wavelength tables. The classification program [4] was used to classify the spectral lines. It shows all suggestions of possible transitions for the wavelength of spectral lines taking into account the selection rules for electric dipole radiation. We discovered 10 new fine structure energy levels of even parity. The magnetic dipole hyperfine interaction constants A have been determined for 48 energy levels. They are compared with reference values [5-8], if avalable. 12 A constants of even parity levels and one A constants of odd parity level have been measured for the first time.