The 4(3)Pi(g) State of Na(2): Vibrational Numbering and Hyperfine Structure.
The Na(2) 4(3)Pi(g) state has been studied by continuous-wave (cw) perturbation-facilitated optical-optical double resonance (PFOODR) fluorescence excitation and resolved fluorescence spectroscopy. The absolute vibrational numbering was determined by resolved fluorescence to the a(3)Sigma(+)(u) state. The OODR excitation lines of the 4(3)Pi(g) (Kv, N) <-- b(3)Pi(u) (Kv(b)('), J') approximately A(1)Sigma(+)(u) (Kv(A)('), J') <-- X(1)Sigma(+)(g) (Kv", J") transitions show hyperfine splittings, and the hyperfine coupling scheme of the upper 4(3)Pi(g) levels is case b(betaS). Although this 4(3)Pi(g) state dissociates to the 3p + 3p atomic limit, it is a Rydberg state at a small internuclear distance, and the hyperfine splitting is caused mainly by the Fermi contact interaction of the varsigma(g)3s valence electron with the nuclei. The Fermi contact constant was determined to be b(F) = 218.3 +/- 3.9 MHz. Copyright 1999 Academic Press.
Lazarov
G
Department of Physics, Temple University, Philadelphia, Pennsylvania, 19122
Lyyra
AM
Li
L
Huennekens
J