In this paper, the charge density, electric field, and corona current distr
ibutions in the corona triode are calculated using a hybrid technique; the
finite-element method and the boundary-element method are combined with the
method of characteristics. The characteristic lines are traced backward fr
om points of the analyzed domain to the corona wire. The current density, e
lectric field, and space-charge density distributions can be controlled by
changing the configuration of the system, The voltage applied to the grid p
lays an important role in controlling the corona current. Results of calcul
ations in a number of different cases show the influence of different param
eters on the characteristics of the corona triode.