The use of time- and space-resolved emission data for fundamental studies of a pulsed ICP

Abstract

The power delivered to an inductively coupled plasma (ICP) is repetitively switched off and on to add the dimension of time to fundamental studies of the ICP's behavior. Described are time- and space-resolved measurements of emission intensities from argon and calcium that were recorded with two primary objectives. The first is the identification of the means by which energy is transported from the load coil and transferred to the analyte in the normal analytical zone. The second is the identification of regions where and times when the study of non-emitting species will be most productive. The data suggest that analyte excitation depends on species created 1-2 ms earlier and lower in the plasma. Emission data alone are insufficient for identification of the energy carrying species, but they suggest other types of measurements will be most effective during the 200 μs decay period. Spatial shifts in the plasma structure emphasize the need for caution in the interpretation of single-point, time-resolved measurements. © 1986.