Comparison of the characteristics of inductively coupled plasmas sustained in short and extended laminar flow torches

Abstract

A comparison of molecular band emission spectra, electron densities, temperatures and analyte emission intensities has been carried out between plasmas sustained in short and extended laminar flow plasma torches (LFT). The molecular band emission is greatly reduced in the extended torch due to the removal of air entrainment. As a result of this, electron densities and temperatures are higher in the extended torch. The rate of decay in analyte emission in the short torch is also greater compared with the extended torch. The models for electron temperature measurements break down in the absence of a torch extension due to the ingress of molecular species into the plasma.