A NEW SPECTRAL EMISSION SOURCE OF ROTATIONALLY COOLED MOLECULAR-IONS - APPLICATION TO SUPERSONIC EXPANSIONS OF CO AND CO2 GASES

A new emission source for the spectroscopy of rotationally cooled mole cular ions has been developed in which a Penning-type electric dischar ge is established through a supersonic free jet. CO and CO2 gases were used to rest its working conditions. Several previously unobserved em ission bands were identified, among them one that probably originates from the CO2+ ion. Moreover, anomalous rotational intensity distributi ons in the CO+ B-X emission observed from the excitation of rotational ly cooled CO2 suggest the existence of a dissociative bent electronic state in the CO2+ ion.