The Production of Positive Ions in Resonant Cavities

An extensive series of experiments designed to yield information on the mechanisms of ultra-high frequency discharges is described. The main conclusions are that such discharges exhibit a high negative space charge due to secondary electron emission from the walls of the cavity and that ion production is inhibited by the space charge trap so formed, that under certain conditions extremely intense electron beams may be obtained from a resonant cavity, and that fairly large ion currents may be obtained by the interaction of the emergent gas and the emergent electron beam in the exit orifice of the cavity.