The 31Πg state of Na2 is experimentally investigated by using high resolution cw optical-optical double resonance spectroscopy. A single line Ar+ laser (total of 9 lines) is used to pump the sodium dimers from thermally populated ground state X1Σg+ to the intermediate B1Πu state. Then a single mode Ti:sapphire laser is used to probe the 31Πg state. Violet fluorescence from highly Rydberg excited states (mainly 23Π g or 33Πg states which are transferred from 31Πg state via collisions) to the a3Σu+ state is monitored by a filtered photomultiplier tube and a lock-in amplifier. Compared with previous studies [C.C. Tsai, J.T. Bahns, W.C. Stwalley, J. Chem. Phys. 99 (1993) 7417], a wider range of rotational quantum numbers of data field are observed. A set of Dunham coefficients and the Rydberg-Klein-Rees potential energy curve of the 31Πg state are deduced from all the observed rovibrational levels.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry