PHOTOEMISSION OF COMBUSTION AEROSOLS USIN G AN EXCIMER UV-RADIATION SOURCE

A newly-developed Excimer radiator (KrCl, wavelength lambda = 222 nm) is used to examine combustion aerosols by means of photoelectric charg ing. The dependence of the charging on the lamp performance and the du ration of the radiation is investigated. Two operating ranges can be d ifferentiated: the linear range and the saturation charge. The results are compared to those obtained by charging with a conventional, low-p ressure mercury lamp (lambda = 184.9 nm). It is shown that particles f rom different sources (petrol engine, diesel engine, cigarette smoke) display a wavelength dependence characteristic of the specific source and can therefore be differentiated by measurement using at least two wavelengths. A possible application of such a system exists in the fie ld of pollution detection, air conditioning or fire alarm systems. The miniaturised, easily-driven excimer lamps are suitable for these appl ications due to their stability, narrow bandwidth and the selectabilit y (by choosing the gas filling) of the wavelength of the emitted light .