GENERATION OF [H3O](+).(H2O)(N) CLUSTERS BY POSITIVE CORONA DISCHARGEIN AIR

A mass spectrometric study of ions extracted from DC positive corona d ischarges in ambient air has been carried out within the air pressure range of 2.5 kPa-20 kPa, The multicomponent character of the mass spec tra was confirmed. The dominant series of ions observed in the mass sp ectra were of the type [H3O](+).(H2O)(n) especially in the low current regime. In the high current regime, pr 'streamer' regime of the coron a discharge, atomic nitrogen and oxygen ions were also discovered, but the intensities of these were relatively low in comparison with the i ntensities of peaks corresponding to the molecular ions. A new mechani sm responsible for the disappearance of [O-2](+) and its hydrated form s from the mass spectra is given. This is based on the set of stepwise processes originated by the three-body process: O-2(+) + H2O + M --> O-2(+). H2O + M The model is also capable of explaining some other phe nomena initiated by the presence of wafer in the air,as well as the ef fects observed in dry air, (C) 1997 John Wiley & Sons, Ltd.