Hybrid plasma monitor. A ground electrode is spaced apart from a high
voltage electrode supporting an electric discharge therebetween to
generate a plasma. The ground electrode and the high voltage electrode
form an annular region into which a sample is introduced for generating a
plasma. Microwave radiation couples into the plasma to sustain the
plasma. A light detector such as a spectrometer receives light resulting
from atomic emissions from the sample to analyze elements in the sample.