Mass spectrometric investigation of the ionic species in a dielectric barrier discharge operating in helium-water vapour mixtures

摘要: Using advanced mass spectrometry the chemistry of ionic species present in an atmospheric-pressure parallel plate dielectric barrier discharge (DBD) with a single on powered electrode have been identified. The was driven helium controllable concentrations water vapour using excitation frequency 10 kHz and applied voltage 1.2 kV. Both negative positive ions were identified their relative intensity determined variation concentration discharge, inter-electrode spacing, gas residence time nominal power. most abundant family , while dominated by those form n up to 9 both cases. Negative responded similar way changes operating parameters, particular response depending ion mass. Increasing spacing led increase large clusters. However, increasing plasma region power resulted fragmentation clusters produce smaller ions.