Abstract: A preferably fully impregnated dispenser cathode member or the like forming part of an electron tube, electron beam generator or the like is initially heated by any suitable means to a temperature sufficient for low level electron emission from its rear surface. A hot plate member of preferably equal size is disposed behind the cathode and can either be part of or the means for initially heating the cathode member or it can be heated with the cathode member to the aforementioned cathode member's rear surface low level emission temperature. A sustainer voltage is applied between the cathode member and the hot plate member sufficient to draw a current comprising electron flow from the cathode member to the hot plate member across the space separating them.