High resolution laser induced fluorescence spectroscopy of highly excited vibrational levels in NaAr: A2∏r and B2∑+

This laser induced fluorescence study of NaAr reports the direct observation of vibrational and rotational structure of the B2∑+ state through spectroscopic means of Reference 1. Crossed laser and supersonic molecular beam technique is used. We study highly excited vibrational levels at both A2∏r and B2∑+ states. Several types of rotation induced perturbations are encountered and analyzed. Preliminary intensity calculations for the B‐X system lead us to believe that the adiabatic B2∑+ well minimum must be at smaller internuclear distance than has been estimated before. We estimate that 5.5 A < RBe < 6 A and that the B2∑+ state is at least 30 cm−1 deep. This is in agreement with the latest high resolution scattering data2.