Abstract: An emitter for ion generators or air ionizers shaped as a fan and provided with a boss which may also act as a socket, so that the emitter may be either rested on a vertical pin or needle or suspended magnetically from a fixture containing a suitable magnet. In either case, application of voltage will produce a corona discharge of electrons from points at the tips of the blades, and the emitter will revolve or spin from reaction to the forces produced by this discharge. In so revolving, it acts as a fan and induces a current of air to help disperse the ions produced.