The Zeeman Pattern of the Hyperfine Structure Lines of the Resonance Line of Mercury

Abstract

The Zeeman pattern of each of the five hyperfine structure lines of $\ensuremath{\lambda}2537$ ($1^{1}S_{0}\ensuremath{-}2^{3}P_{1}$), the resonance line of mercury, has been obtained in fields from 0 to 7 kilogausses. With certain very significant exceptions each one forms a $\frac{3}{2}$ normal Zeeman triplet, and is independent of its neighbors, that is, no Paschen-Back effect appears. The parallel branch of one of the five lines actually shifts its position with changes in the field strength. Each one of the five lines has two $\frac{3}{2}$ normal perpendicular branches. In addition three of them have one or two extra perpendicular components. Attention is called to the relations between these results and experiments on the polarization of mercury resonance radiation. One is warned against any theoretical explanation of the latter phenomena until more is known of the hyperfine structure of the energy levels of mercury. A quartz Lummer-Gehrcke plate was used for the analysis. One rather unusual method of employing it is described.