Radiative lifetimes, quenching cross sections and population mechanisms of the C1Πu, 23Πg and 1 3Δg states of 7Li2

✍ Scribed by Th. Weyh; K. Ahmed; W. Demtröder

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 653 KB
• Volume: 248
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)01326-1

✦ Synopsis

The laser-and collision-induced fluorescence of Li2 molecules in a heat-pipe, excited by a tunable frequency-doubled mode-locked cavity-dumped cw dye laser into selected rovibrational levels of the C lI1. state, was observed with spectral resolution using a monochromator and with temporal resolution using the single-photon counting technique. The effective lifetimes of the directly excited C II1, state and of the collisionally excited 23Iig and 13Ag states were measured as a function of the lithium vapor pressure and the argon buffer gas pressure. This yields the radiative lifetimes and collisional quenching cross sections of the three states. It is shown that the population mechanism of the 2 31Ig and 1 3Ag states is the collisional energy transfer from the C ~ IIo state. Measurement of the total fluorescence intensities emitted from the excited states under cw laser excitation provides the cross sections for the collisional population transfer.