Direct current glow discharges in atmospheric air

Direct current glow discharges have been operated in atmospheric air by using 100 mu m microhollow cathode discharges as plasma cathodes. The glow discharges were operated at currents of up to 22 mA, corresponding to current densities of 3.8 A/cm(2) and at average electric fields of 1.2 kV/cm. Electron densities in the glow are in the range from 10(12) to 10(13) cm(-3). Varying the current of the microhollow cathode discharge allows us to control the current in the atmospheric pressure glow discharge. Large volume atmospheric pressure air plasmas can be generated by operating microhollow cathode discharges in parallel. (C) 1999 American Institute of Physics. [S0003-6951(99)01425-4].