  Physical processes that determine the generation of ion beams with a high
emission current density in electrohydrodynamic emitters are considered.
Electrohydrodynamic effects, which are manifested in the features of ion
emission, and the kinetics of ion interaction in high-density beams are
discussed. The factors that determine the size of the emission zone, stability
of emission at high and low currents, cluster generation, increase in energy
dispersion, and decrease in beam brightness are analyzed. The problems of the
practical maintenance of the stable functioning of the EHD emitters are
considered. The practical applications of EHD emitters are considered.
