Beam-Foil Spectra of Boron 450–5000 Å*

Electronic transitions in B i–B iv have been studied with the beam-foil technique. Over 100 spectral lines were observed between 450 and 5000 Å. Only half of the lines could be assigned to earlier known boron transitions. Classifications are given for several of the new lines. Mean lives of 33 excited levels in B i–B iv were measured. In most cases the results are in good agreement with theory.