The Lateral Distribution of Current from Wire-to-Plane Coronas

For wire-to-plane coronas in ambient air, the lateral distribution of current at the plane has been measured. To a first approximation, it has been found that for positive dc, negative dc, and 60-Hz ac coronas 1) the shape and width of the distribution curves are independent of polarity; 2) the shape and width of the curves are independent of current between 3 and 35 AA/cm; and 3) the width of the current distribution is directly proportional to the wire-to-plane spacing S. Specifically, if the "beamwidth" W of the current distribution is defined as the full lateral distance subtended at one half of the peak current, then W = 1.4 S.