Radiative lifetimes of selected rovibronic triplet levels of the CO molecule

Radiative lifetimes of individual rovibronic levels of the perturbed a′ 3Σ+(v=14) and the e 3Σ−(v=5) states of the CO molecule have been measured under collision-free conditions using state selective excitation and measuring the temporal decay of the subsequent fluorescence. The accuracy of the measurements was typically 3% to 5%. The unperturbed triplet lifetimes and the corresponding spin-orbit interaction constants have been determined. Excellent agreement was found between the measured and the calculated lifetimes based on data of Field and co-workers. It is also shown that under favorable conditions lifetime measurements are significantly more sensitive to the mixing coefficients ‖β‖2 than wavelength measurements.