Multiple Nature of Elementary Sources of Radiation—Wide-Angle Interference

Abstract

It has been shown possible in wide-angle interference experiments to analyze radiation with respect to its multipole character. The fluorescence from ions of europium in solution consisted of different kinds of radiation in that they possessed different interference properties. From the behavior of the fringe systems, one group of spectral lines was identified as arising from magnetic dipoles while two other groups had their origin in the forced oscillations of electric dipoles. The multipole character of the radiation of a quantum transition was found modified by a change in the microscopic fields about the emitting ions.