(6P-5D)-branching ratio in Ba II

G. T. Xu, Xinqiang Wang, William E. Cooke

The authors have measured the population in each of the 5d 3/2 (m j ) ion states following autoionization of the (6p 3/2 nd) J=MJ=3 state by using a circularly polarized laser to excite the Ba + 5d 3/2 to 6p 1 2/ transition, and observing the polarized fluorescence of the Ba + 6p 1/2 to 6s 1/2 transition. The branching ratios for autoionization into each of the 5d 3/2 in l j channels can be related to these ion populations by using angular momentum algebra. The fractions of ions found in the m j =+3/2, +1/2, -1/2 and -3.2 state of the 5d 3/2 ion states were 5.9(+or-2.6)%, 4.5(+or-1.9)%, 3.2(+or-1.3)% and 1.9(+or-0.6)% respectively. This method can easily be generalized to measure the branching ratio for autoonization into other ion states.

R. Brout

Wei-Guo Jin, Masayuki Kawamura, Tatsuya Minowa

Peter G. Whitkop, J. R. Wiesenfeld

The lowest optically metastable excited state of barium, Ba(5d 3DJ), was populated by laser excitation of the 6p 1P01←6s 1S0 (λ=553.5 nm) transition followed by the spontaneous emission 6p 1P01→5d 3DJ (λ∼1130 nm). No evidence for the normally spin allowed transition 6p 1P01 →5d 1D2 (λ=1500 nm) was obtained. The deactivation of Ba (5d3DJ) by Ba (6s 1S0) is extremely efficient proceeding with a thermal cross section of 1.3±0.1 nm2 at ?730 K. This is in sensible accord with recent calculations of Ba2 potential curves.

Markus Hubrich, H. Knab, K. H. Knöll +1 more

William E. Cooke, G. T. Xu

We report a measurement of the branching ratio for production of 5d{sub 3/2} ions in various m{sub j} states following the autoionization of the (6{sub p1/2}nd{sub 5/2})J=M{sub J}=3 states of barium in an electric field. By detecting the population in different ion states, rather than the electron distribution, we are able to measure the decay routes even in the presence of an electric field. These branching ratios show pronounced new structure, even at fields as low as 30 V/cm.