CII. Fine structures of spectrum lines

Abstract

Abstract Many spectral lines of non-hydrogenic atoms have fine structures which arise from transitions between the components of complex spectral levels. In none of the cases so far studied can fine structures be due to isotopy. Elements which are known to have only a single species of nuclens frequently have complex spectral lines. In general, some of the satellites which can be predicted from the energy diagram do not appear. In the case of thallium a fine quantum number f may be introduced, with a selection principle to govern its changes, but for other elements, no selection principle has been discovered. Fine structures have proved to be an aid in classifying spectral lines. At present it is believed that slight quantized variations in the configuration of loosely bound underlying electron shells suffice to explain the existence of all the fine structures we have studied.