Laser spectroscopy of Na i quartets

Abstract

By using a pulsed hollow-cathode discharge, metastable atoms are produced in the (2$p^5$3s3p)${}^4$ $D_{7/2}$ and (2$p^5$3s3p)${}^4$ $S_{3/2}$ levels of Na i. A tunable laser is used to excite these atoms to levels in the 2$p^5$3s3d and 2$p^5$3s4s configurations, and thereby to establish a partial Grotrian diagram for the quartet system. Several possible Na i xuv laser systems are described.