A Study of Inductively Coupled Plasma Torch Configurations

Abstract

Plasma torch design and shapes were studied to facilitate ignition, to concentrate the sample into a narrow central channel, to raise the sample to excitation temperatures with optimized efficiency, and to avoid clogging by organic samples such as residual oil. Observation of the influence of the torch configuration on ignition emphasized the importance of the shape and rate of the gas flows. Operating conditions of torches with diameters from 7 to 18 mm were calculated using a computer model, and predicted operation of small diameter torches requires high magnetic flux density. Experimental verification of an improved torch design demonstrated a higher efficiency, a lower gas consumption, and an easier ignition than conventional configurations.