On Particulate Formation in Ambient Air Induced by X-ray and Ultraviolet Radiation 2004-01-2330

The author has investigated and analyzed the formation of particulate products in ambient air under the irradiation of X-ray or ultraviolet light that were reported by G. Pffeferkorn. They were examined by both transmission and scanning electron microscopes. Further studies and investigation were conducted using principles in radiation chemistry, photochemistry, and reaction kinetics. IR spectrometry, gas chromatography, and mass spectrometry have been utilized to reveal different oxygen-containing groups, e.g., -OH, -CHO, -C=O, and -COOH in the particulate materials. In conclusion, the particulate matters are molecules consisting of hydrocarbon groups and with high molecular weights much greater than 200. The size and mass of all types of particulates were found to increase in proportional to aging time, hydrocarbon concentrations, and humidity. The formation of such particulate matters in spacecraft environment is considered possible. The extrapolated knowledge on such particulates will be beneficial in the design and operations of future spacecraft that encounters UV and X-ray radiations.