OPTICAL-OPTICAL DOUBLE-RESONANCE SPECTROSCOPY OF THE 2(1)PI(G) STATE OF NA-2 USING AN ULTRASENSITIVE IONIZATION DETECTOR

Using optical-optical double resonance and an ultrasensitive ionizatio n detector, we have been able to extensively study a wide range of int ernuclear distances for the 2(1)II(g) state of Na-2. A total of 80 vib rational levels (0 less than or equal to v less than or equal to 43 ar e from previous work using filter-PMT detection) which covered more th an 99.9% of the well depth were observed in this state. The Rydberg-Kl ein-Rees (RKR) potential energy curve was constructed with a maximum o uter turning point R(79+) = 18.08 Angstrom. The potential curve at lon g range, where it can be described in terms of C-n coefficients, is al so discussed. (C) 1994 Academic Press, Inc.