Selective Excitation of Spectra by the High-Frequency Discharge

Abstract

IN a series of preliminary investigations on the excitation of spectra by the high-frequency discharge, several interesting phenomena connected with intensity distribution have been observed, some of which have already been reported¹. Further work indicates that these consist essentially in a redistribution of intensity among different band-systems of a diatomic molecule (that is, among different electronic energy levels) or among atomic energy states of different multiplicities. Thus the mercury spectrum observed shows that under certain well-defined and reproducible conditions, as for example pressure of gas, frequency of exciting oscillations, etc., only those lines are present which involve triplet initial states. Similarly, again under definite conditions, mainly those band systems of carbon monoxide are excited which involve only the singlet levels.