The Spark Spectrum of Cobalt, Co II

A further examination of the Co II spectrum, based on the previous work of Meggers, has been made. A magnetic analysis shows that Meggers' classification of the terms now called d⁷p⁵F⁰, ⁵D⁰ should be interchanged, except for the term ⁵F₅⁰. Since Meggers' results were obtained from intensity rules, the author's ⁵F⁵F⁰ and ⁵F⁵D⁰ multiplets show irregular intensities. The strongest lines in these multiplets are, respectively, ⁵Fₙ⁵F⁰_n-1 and ⁵Fₙ⁵D⁰ₙ. The magnetic analysis also shows that Meggers' terms ³D should be d⁷s⁵P and that his ³P, ³D¹, and ³F should be partly d⁷p⁵P⁰ and ⁵D⁰. In addition, the terms d⁷s³F, d⁷p³D⁰, ³F⁰, ³G⁰, ⁵S⁰, ⁵P₀, ⁵D⁰, and the lowest terms d⁸³F have been found. The location of the second member of the d⁷s⁵F³F series gives an I. P. of 16.9 volts from d⁷s to d⁷ and 17.3 volts from d⁸ to d⁷, in practically exact agreement with the predictions of Dr. H. N. Russell.