An induction heater is used to evaporate the sample held in a carbon cup, and the vapor is then excited by a spark. The two main functions of a source, evaporation and excitation, are thus separately controlled. A study of the boiling point temperature of the sample can be used to differentiate elements and compounds.
ARTHUR G. ROUSE, "A New Source for Spectro-Chemical Analysis," J. Opt. Soc. Am. 40, 82-83 (1950)