Potential of Surface-Discharge Microplasma Device as Ion Source for High Efficiency Electrical Charging of Nanoparticles

Abstract

In order to evaluate the potential of surface discharge microplasma device (SMD), long SMD was installed in the surface-discharge microplasma aerosol charger (SMAC) and the charging performance was measured for aerosol nanoparticles. The intrinsic charging efficiency for 5-nm particles was about 60% and that for 10-nm particles was 90% at the aerosol flow rate of 1.5 LPM because long SMD is capable of generating uniform concentration ions over wide area. The size-dependent charging efficiencies for these aerosol nanoparticles with a diameter between 3 and 30 nm were in good agreement with those predicted by the diffusion charging theory. The product of ion concentration (N) and charging time (t) estimated by the diffusion charging theory was 3.0×10¹³ sm^-3, which is one order of magnitude higher than the previously reported chargers. These results confirm the high potential of SMD as ion source for charging aerosol nanoparticles.