ABSTRACT
The photoionization of aerosols can play an important role in increasing the electron concentration and hence, electrical conductivity of dusty gases. The photoionization of macroparticles makes the most important contribution in the generation of dusty plasma if the radiation quantum energy exceeds the work function of macroparticles, but remains below the ionization potential of neutral gas species. The energy necessary for ionization of macroparticles is related to their work function, which is usually lower than the ionization potential of atoms and molecules. Assuming that the ionization potentials determine the exponential growth of ionization rate with temperature, one can conclude that the thermal ionization of aerosol particles can be very effective and provide high electron density and conductivity at relatively low temperatures. Macroparticles can be present in a discharge gap for different reasons, for example, air impurities or detachment of micro-pikes from the electrode surface.
