The first spark spectrum of copper

Abstract

Abstract The fundamental multiplets of the copper spark spectrum were first described in 1927.* They consist of the combinations between a low 3&1D a middle set of terms 3&1P, D, F, and a high 3&1D. That partial analysis revealed that the theory of series limits in complex spectra as given by HUND was certainly not applicable in spectra of the type of Cu II and might indeed be quite erroneous. Since the lack of an adequate vacuum spectrograph at Princeton prevented further progress in the analysis, Professor GIBBS and Mr. KRUGER at Cornell undertook the problem and were successful in adding two more 3&1D terms to the series. Those terms quite definitely proved the inapplicability of the original Hund theory of limits, which had in the meantime been changed rather radically to correspond to the observations in this and other spectra. It does not, in its present form, pretend to predict limits except in the simpler cases.§