Migration of a charged particle in a nonuniform sinusoidal field: mechanisms in liquid and gaseous media, optimization

The repulsion of charged particles in AC fields is briefly reviewed. The equations of motion in a coaxial field configuration are given, using detailed expressions for the particle charge in liquids and gases. Numerical results are presented and it is shown that an optimal frequency can be found for the fastest particle migration. Results are also evaluated using the concept of repulsion potential. The repulsive force exerted by AC electric fields on particles in liquids and gases are compared, showing that in liquids the effect exists only for large particles (above 1 mm), whereas it can be important for particles above 10 mu m in gases. It is also shown that the effect exists only at very low frequencies, probably matched to the mechanical relaxation time.<>