Hyperfine structure and lifetime measurements in the 4s2nd 2D3/2 Rydberg sequence of Ga I by time-resolved laser spectroscopy

Abstract The hyperfine structure (HFS) constants of the 4s 2 n d 2 D 3/2 ( n =6–18) Rydberg sequence and the 4s 2 6p 2 P 3/2 level for two isotopes of 69 Ga and 71 Ga atoms were measured by means of the time-resolved laser-induced fluorescence (TR-LIF) technique and the quantum beat method. The observed hyperfine quantum beat spectra were analyzed and the magnetic-dipole HFS constants A as well as the electric-quadrupole HFS constants B of these levels were obtained by Fourier transform and a program for multiple regression analysis. Also using TR-LIF method radiative lifetimes of the above sequence states were determined at room temperature. The measured lifetime values range from 69 to 2279 ns with uncertainties no more than 10%. To our knowledge, the HFS constants of this Rydberg sequence and the lifetimes of the 4s 2 n d 2 D 3/2 ( n =10–18) levels are reported for the first time. Good agreement between our results and the previous is achieved.