Rovibrationally and Time-Resolved Radiative Lifetime and Collisional Cross Section Measurements of the 61Σ+g(v=6, J=31) State of Molecular Sodium

Abstract

In recent years, cold and ultracold alkali diatomic molecules have been at the forefront of quantum chemistry and manybody physics. Thus, there has been an increased interest in the determination of the radiative lifetimes for accurate knowledge of the transition dipole matrix elements of these molecules. In this work, we report on radiative lifetime measurements of the sodium diatomic molecule of the 61Σ+g (v=6,J=31) and 61Σ+g (v=8,J=31) molecular levels by a time-resolved laser spectroscopy technique. The ion-pair character of these potential energies makes their lifetimes interesting because of the unusual behavior of their transition dipole moments. The excitation to the Na2 61Σ+g(3s+5s) electronic state was done using two synchronized pulsed lasers, directed to the sodium heatpipe oven, via X1Σ+g (v=0,31) → A1Σ+g (9,30) → 61Σ+g (8,31) and X1Σ+g (v=0,31) → A1Σ+g (7,30) → 61Σ+g (6,31) transition paths. Disperse molecular fluorescence decay time as a function of argon buffer gas was recorded using a time-correlated photon counting technique. Radiative lifetime was measured and collisional cross section between the excited sodium molecules and ground state argon atoms was extracted.

Keywords

• Molecular physics,Spectroscopy,Lifetimes

References

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