Fine Structure of the Beryllium Fluoride Bands

Abstract

Wave-length measurements of BeF bands.—New wave-length measurements have been made of the rotational lines of the BeF bands in the regions $\lambda \lambda 3009.5-3026.3$, 2908.9-2927.8, and 3126.1-3140.8, which include all the stronger lines of the (0, 0), (1, 0) and (0, 1) bands. The source was a cored carbon arc run at atmospheric pressure. The Harvard 21-foot grating was used in the second order, giving a linear dispersion of 0.97 A per mm and an effective resolving power of nearly 100,000. The wave-numbers of the lines in the six branches of each band are tabulated for rotational quantum numbers up to about $K=50\mathrm{}$ in the $R$ branches, 45 in the $Q$ branches, and 30 in the $P$ branches. Visual intensity estimates are also included.