The Spectrum of Trebly-Ionised Selenium

Abstract

THE spectrum of selenium has been investigated (in Prof. Fowler's Laboratory at the Imperial College, in collaboration with Mr. J. S. Badami) from λ7000 to λ700, using different intensities of discharge, through capillary tubes containing selenium metal or the oxide. Between λ1400 and λ500 photographs have also been taken in this institute of the spark spectrum of selenium with a vacuum spectrograph designed by Prof. Siegbahn, having a grating of radius 150 cm., at tangential incidence. With the aid of these, the doublet system of trebly-ionised selenium, due to the configurations 4s²4p, 4s²4d, etc., and 4s4p², has been identified. The characteristic separations are: 4p²P₁ − 4p²P₂ = 4378; 5p²P₁ − 5p²P₂ = 1198; 4d²D₂ − 4d²D₃ = 389, etc. Details of the analysis will be published shortly.