A Novel Version of the Microwave-Coupled Hollow Cathode Lamp for Atomic Emission Spectrometry

Abstract

A new model of the microwave-boosted hollow cathode lamp has been devised, giving considerable improvement in the coupling efficiency of the two types of discharges. For this to be achieved, a resonant cavity is interposed between the cathodic and anodic blocks of the demountable tube, causing the microwave field to interact with the plasma inside the cathode. The performance of this potentiated lamp has been tested discharging a number of elements (Al, C, Cu, Fe, Mo and Ni). In all instances there was a significant increase in intensity of the emitted spectra, together with a noticeable diminution of background; thus signal-to-background ratios of even two orders of magnitude higher than those obtainable by conventional hollow cathode discharge lamps were achieved. An additional advantage of this combined lamp is its high stability of operation.