THERMIONIC ENERGY CONVERTER

1,094,279. Thermionic generators. CSFCOMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. Nov. 19, 1965 [Dec. 1, 1964], No. 49368/65. Addition to 987,627. Heading H1D. In a thermionic generator of the kind described in Specification 987,627, in which a light beam is directed into the generator enclosure to excite neutral gas or vapour atoms and so enhance ionization thereof by electron bombardment, the arrangement is such that the light beam 12 is directed on to the emitter 2 to cause heating thereof without impinging directly on the surface of the collector 3 facing the emitter so that excessive heating thereof is prevented. As shown, the facing surfaces of emitter 2 and collector 3 are of frusto-conical or frusto-pyramidal shape. A hollow conical or prism-shaped reflector 8 is disposed within emitter 2 and may be evacuated to improve thermal insulation. The remaining space within emitter 2 and the interelectrode space 4 contains caesium vapour, the generator enclosure being completed by base 1 insulating ring 5 and sapphire window 7. A light-reflective coating may be provided on base 1 around the emitter 2. A plurality of generators may be mounted on a common base 1 which may be planar, spherical or cylindrical, adjacent collectors being combined, and the emitters being insulated from the base, Figs. 6 and 7 (not shown).