Charge-carrier extraction from air and nitrogen gas streams that entrain charge from dc corona ionizers

Charge decay upon a pre-charged target was studied in a gas flow channel that contained a pair of point-to-plane corona-discharge emitters. Charge decay was primarily determined by charge carriers entrained from the negative corona discharge and gas flow. The positive glow corona removed excess negative carriers and added positive carriers to achieve balanced residual charge on targets. Discharge modes with extended structures, such as streamers in air and nitrogen and sparking, yielded positive and negative charge carriers that were most likely to be entrained. The magnitudes of corona currents in ionizers were of lesser importance.