Hyperfine structure and lifetime measurements of the 6p 2P [formula omitted] fine structure levels of gallium 69 and 71

Abstract

We have determined the natural lifetime and hyperfine structure of the 6p 2P 3 2 and 6p 2P 1 2 levels of 69Ga and 71Ga. The levels were populated in an atomic beam apparatus by means of stepwise excitation using two pulsed dye lasers. The lifetimes, deduced from the fluorescence decay, are 160 ± 35 ns for the 2P 1 2 level and 150 ± 15 ns for the 2P 1 2 level. The hyperfine structure splittings were determined by means of the quantum beat method. The A factor found for 6p 2P 1 2 is 53.3 ± 0.7 MHz for 69Ga and 67.4 ± 0.7 MHz for 71Ga. The A and B factors of 6p 2P 3 2 are for 69Ga 22.4 ± 0.2 MHz and 3.2 ± 0.3 MHz, respectively, and for 71Ga 28.5 ± 0.2 MHz and 2.4 ± 0.3 MHz, respectively. The positive sign of all hfs constants, which cannot be deduced from the quantum beat measurements, is taken from the results of Hartree-Fock calculations.