Electronic gJ Factors, Natural Lifetimes, and Electric Quadrupole Interaction for Rb87 in the np 2 P 3/2 Series of the Rb I Spectrum

Abstract

For Rb87 the level crossing method was applied to the first four levels (n = 5, 6, 7, and 8) of the np 2 P 3/2 series in the Rb I spectrum. By using magnetic dipole interaction constants from corresponding zero field optical double resonance experiments, the electronic gJ factors of 5, 6, and 7p 2 P 3/2 were calculated from the level crossing data. For these levels the natural radiative lifetimes were determined from the half-widths of the level crossing signals. For 8p 2 P 3/2 the a factor was obtained assuming gJ = -1.336 (2). From the measured electric quadrupole interaction constants b, decreasing values of the nuclear quadrupole moment Q were obtained in 5, 6, 7, and 8p 2 P 3/2. When core polarization effects are taken into account, the different 2 P 3/2 levels yield consistent values for the quadrupole moment. We find gJ (5p 2 P 3/2) = -1.3362 (6) gJ (6p 2 P 3/2) = -1.3347 (10) τ (5p 2 P 3/2) = 25.8 (8) ns τ (6p 2 P 3/2) = 111 (3) ns b (5p 2 P 3/2) = 12.510 (57) MHz b (6p 2 P 3/2) = 3.947 (13) MHz Q(5p 2 P 3/2) = 0.131 barn Q(6p 2 P 3/2) = 0.133 barn gJ (7p 2 P 3/2) = -1.3359 (11) a(8p 2 P 3/2) = 6.747 (14) MHz τ (7p 2 P 3/2) = 233 (10) ns b (8p 2 P 3/2) = 0.933 (20) MHz b (7p 2 P 3/2) = 1.768 (8) MHz Q(8p 2 P 3/2) = 0.131 barn Q(7p 2 P 3/2) = 0.133 barn Considering possible sources of error in the evaluation of the quadrupole moment we obtain Q(Rb87) = +0.132 (9) barn.