Abstract:
A pool of liquid cesium is spaced apart from a collector in an enclosed vessel. A laser beam is directed to the liquid cesium pool. The beam is focused to provide sufficient laser power density at the liquid cesium surface to vaporize some of the liquid cesium and ionize the vaporized cesium, and thereby form cesium ions and free electrons. The work function of the collector is different from that of cesium. When the work function is higher, the formed ions are attracted to the collector and the electrons are attracted by the liquid cesium, while the electrons and ions are respectively attracted by the collector and liquid cesium respectively when the work function of the collector is less than that of cesium. Thus, a potential difference is generated by the liquid cesium pool and the collector, sufficient to apply electric power to a load. The collector is held at a higher temperature than the liquid cesium to repel any neutralized cesium ions at the collector surface and any vaporized cesium atoms which are not ionized by the laser beam from the collector in order to facilitate the flow of ions or electrons thereto.
Abstract:
A solar energy concentrator comprises an array of cylindrical Fresnel lenses, all of which are fixedly aligned in the East-West direction. Each lens concentrates the sun rays and forms a line image which extends in the East-West direction. Located below the lenses are individual fluid channels which extend in the EastWest direction and are spaced apart in the South-North direction. Each line image focuses onto preferably not more than two of the channels which absorb heat of the concentrated sun rays. Each channel has a thermostatically controlled valve which controls fluid flow through the channel to take place only when the channel''s temperature and/or the fluid therein exceed a threshold temperature level.
Abstract:
A thermal to electrical power conversion system is disclosed in which switching of electrical currents to a load is performed by solid-state switches in which their Seebeck effect reduces the losses due to the ohmic voltage drops thereacross. In a system with a thermoelectric generator as the power source, the switches are designed with their source electrodes formed by the generator''s cold shoe at a temperature higher than a remotely located heat sink which forms the switches'' drain electrodes. The gate electrodes of the switches are connected to an electronic switch controller, which controls their conduction and cutoff states.
Abstract:
A thermionic cesium diode incorporating a cavity emitter is disclosed. The emitter defines a plurality of relatively shallow cavities extending inwardly from the surface thereof which faces the interelectrode gap. The depths of the cavities are comparable with the electron-neutral mean-free path and the ratios of the depths of the cavities to their diameters are large enough to neutralize electron space charge from occuring thereat.