Reanalysis of the C1Πu state of Na2 based on ultraviolet argon ion laser fluorescence

Six uv lines of an argon ion laser (CR-18 UV) are used to excite the C¹Π_u state of the Na₂ molecule. There are nine fluorescence series observed, two of which are excited from a fairly high vibrational level (v″ ≥ 11) in the ground state. A careful study of the intensities of these transitions reveals that the previous vibrational assignments of the energy levels in the C¹Π_u state are incorrect (too high by 2). A new analysis for this state was carried out and resulting molecular parameters are presented.