On the Theory of Charging of Aerosol Particles in an Electric Field

Abstract

Theories for the charging of aerosol particles by unipolar gaseous ions have been reviewed, and a new theory taking into account both the random thermal motion of the ions and the motion of ions induced by an applied electric field has been developed. The theories have been compared with the experimental data of Hewitt, and the results indicate that the new theory developed in this paper shows the best agreement with the experimental data over the entire range of conditions covered by the data, i.e., for particle size ranging from 0.09 to 0.46 μ radius, for electric field intensities ranging from 300 V/cm to 10 800 V/cm, and for the product N0t, ranging from approx 106 to 5×107, where N0 is the concentration of ions in number of ions per cc, and t is the charging time in seconds.