A VUV atomic emission end-point detector is available from McPherson Inc. The windowless discharge lamp uses helium as a carrier gas for a clean background that allows the introduction of secondary or sample gases from process chambers or other sources. This permits analysis and monitoring of gaseous nonmetals such as fluorine and chlorine. Other applications for the detector include end-point determination of CVD chamber cleaning. When coupled to the company's vacuum monochromator, the system can detect emissions from 30 nm to the visible spectral region.