Spectral and Noise Characteristics of a Xenon Microwave-Induced Plasma Lamp

Abstract

Xenon lamps, filled at various pressures from 0.9 to 5 atmospheres and activated by an electromagnetic-surface-wave-produced plasma, are evaluated for their optical spectrum characteristics in the uv-visible region. The influence of several operating parameters on their optical emission spectrum and noise characteristics is reported. These microwave-induced lamps are compared with a commercial 150 W high-pressure xenon short-arc lamp in regard to their use as continuous sources of uv-visible radiation. They are more stable but are less intense than the short arc. Furthermore, the intensity of the line spectrum that is superimposed on the continuum is comparatively larger than with the short arc. The results obtained indicate, however, that it is possible to decrease the line intensities with respect to the continuum intensity as well as to improve the signal-to-noise ratio and to increase the total emitted intensity by increasing the gas pressure and/or the microwave power. These lamps may thus be considered as potential highly stable, low-noise spectrometric continuum sources.