Abstract
The observed deposition, on a collector placed in the drift region outside the source, of unipolar ion flow in corona discharges is strongly dependent on the current density distribution in the ionisation sheath(source's region of support) enveloping the active electrode. Such a distribution, whose knowledge is the prerequisite for an optimal design of corona-based electrostatic devices and corona-free systems, results still undetermined. Therefore, an inverse source problem has been adopted for reconstructing corona source features. To this end, a universal law governing the ion flow distribution in the drift region has been discovered long after an intense experimental activity. The value of the present law consists in being virtually interpretable as the boundary condition, at the source, needed for successfully resolving a forward space-charge-dominated field problem by a method based on Deutsch's hypothesis.