A moderated thermionic core assembly has been provided which employs vapor chamber condenser-cooled stacked thermionic fuel elements. A cylindrical moderator block is provided with a plurality of radial wells drilled in an ordered array about the periphery of the moderator block. Each well is adapted to receive a tubular fuel element which includes two series-connected nuclear fueled thermionic converter elements having a neutral plasma maintained between the emitter and collector electrodes of each converter. Each fuel element includes a vapor chamber condenser which extracts excess heat from the collectors and transmits it to an external reflector from which the excess heat is radiated to space.
A thermionic fuel element for electrical power generation having an all bonded sheath-sheath insulator collector assembly. The thus bonded assembly is provided with at least one internal groove by which an emitter intercell sub-assembly is bonded to the first-mentioned assembly. The subassembly is constructed to provide the required electric interconnections between a series of interconnected collector-emitter units or cells as well as providing passageways for an alkali metal vapor located in an interelectrode space, while providing proper spacing between the collector and emitter units thereof. In addition each sub-assembly includes means which readily allows the sub-assembly to be inserted, aligned and secured to the first-mentioned assembly while supporting the emitter, maintaining the emitter to collector gap, and providing a heat transfer path to the first-mentioned assembly.
A thermionic reactor electrical hookup and control system which provides for regulation of plant electrical output, individual control of fuel element emitter temperatures, and isolation of fuel element failure events. The control system is applicable to fast and thermal spectrum thermionic reactors for ground, sea and space applications.
A thermoelectric power system particularly adaptable for use in outer space in which a nuclear reactor heats a working fluid, which in turn supplies heat to a plurality of thermoelectric generators spaced about a ring-shaped support. A first heat pipe is employed to couple heat between the hot fluid and hot junction of the thermoelectric element of each generator, and a second heat pipe couples heat away from the cold junction of each thermoelectric element. Each of the second heat pipes are elongated flexible units adapted to be folded upon launch of the system of a space vehicle and thereafter extended in space to provide a substantial area of radiation of heat to be discharged.
