
Article
Time-resolved double-resonance spectroscopy: Lifetime measurement of the 61Σ+g(7,31) electronic state of molecular sodium
J. Chem. Phys.
(2018)
Abstract
We report on the lifetime measurement of the 61Σ+g(7,31) state of Na2 molecules, produced in a heat-pipe oven, using a time-resolved spectroscopic technique. The 61Σ+g(7,31) level was populated by two-step two-color double resonance excitation via the intermediate A1Σ+u(8,30) state. The excitation scheme was done using two synchronized pulsed dye lasers pumped by a Nd:YAG laser operating at the second harmonics. The fluorescence emitted upon decay to the final state was measured using a time-correlated photon counting technique, as a function of argon pressure. From this, the radiative lifetime was extracted by extrapolating the plot to collision-free zero pressure. We also report the calculated radiative lifetimes of the Na261Σ+g ro-vibrational levels in the range of v = 0–200 with J = 1 and J = 31 using the LEVEL program for bound-bound and the BCONT program for bound-free transitions. Our calculations reveal the importance of the bound-free transitions on the lifetime calculations and a large difference of about a factor of three between the J = 1 and J = 31 for the v = 40 and v = 100, respectively, due to the wavefunction alternating between having predominantly inner and outer well amplitude.
Keywords
- spectroscopy,
- lifetimes,
- dimer,
- sodium,
- diatomic,
- homonuclear,
- molecule
Disciplines
Publication Date
November 26, 2018
DOI
https://doi.org/10.1063/1.5061729
Citation Information
Michael Saaranen, Dinesh Wagle, Emma McLaughlin, Amelia Paladino, et al.. "Time-resolved double-resonance spectroscopy: Lifetime measurement of the 61Σ+g(7,31) electronic state of molecular sodium" J. Chem. Phys. Vol. 149 Iss. 20 (2018) Available at: http://works.bepress.com/seth-ashman/27/