ABSTRACT
A microwave-powered slab-line cavity was used to excite a discharge in low pressure argon or neon and to demonstrate the sputtering of conducting and non-conducting samples by a microwave excited discharge. Both optical emission spectroscopy and mass spectrometry were used as detection systems. The dependence of the signals on gas pressure and net microwave power was investigated.
ABSTRACT
High resolution studies using Fourier transform spectrometry of the spectra emitted in the visible and ultraviolet regions by a microwave boosted glow discharge source have shown that when the source is operated in the dc (unboosted) mode, two anomalous forms of line profile occur for some analyte elements. (1) Some Fe I lines appear to have a triangular base of half-width about five times greater than that of the line proper. (2) Some Fe II and Ti II lines exhibit satellites about 8 cm(-1) wide and an intensity of up to 2% of the peak value on either side of the main line. Both effects depend on the carrier gas and its pressure and are much less pronounced or even absent in the boosted mode. They could both affect the accuracy of analytical results, particularly for depth-profiling. Further studies are in progress.
ABSTRACT
The use of neon as the operating gas for the analysis of aluminium samples with the microwave boosted glow discharge source has been studied. A new type of anode tube allowed the gas to enter the source near the sample surface so that more material was transported into the discharge. Erosion rates have been measured under conditions optimised for high line-to-background ratios and found to be lower than with argon (9 and 21 n/s, respectively). Despite the lower erosion rate the detection limits measured for a number of elements in aluminium are in the range 0.02-1 microg/g and comparable to those obtained with argon as the operating gas.
