Abstract

We have demonstrated a technique which enhances emission lines of core-excited Na transitions occurring in a hollow-cathode discharge. The technique should apply to other alkali atoms and could help in identifying the core-excited visible spectra of heavier alkali atoms. In our experiment, stored population is produced by the discharge in the Na-ion metastable level 2p⁵3s J = 2. A pulsed dye laser is used to transfer this population to a higher ion level of the 2p⁵3p configuration. Core-excited neutral atoms are subsequently produced by an exothermic charge transfer from ground neutrals to the enhanced parent 2p⁵3p ion population. We observe enhanced fluorescence (2 to 3 times above background levels) from neutral 2p⁵3s3d, 2p⁵3s4s, and possibly 2p⁵3p² configurations when the metastable ion population is transferred to higher ion levels.

© 1987 Optical Society of America