Open AccessSNAP PROGRAMS. THERMIONIC ISOTOPIC POWER SYSTEMS. Quarterly Progress Report No. 6, January 1 through March 31, 1961
Publication year - 1961
Language(s) - English
Resource type - Reports
DOI - 10.2172/4073450
Subject(s) - nuclear engineering , thermoelectric generator , thermionic emission , mechanical engineering , materials science , electrical engineering , thermoelectric effect , engineering , nuclear physics , thermodynamics , physics , electron
Progress in thermionic technology necessary for the development of power supplies utilizing radioisotopes as heat sources is reviewed. An investigation was made of the characteristics of cesium-filled thermionic converters operating in the low temperature region. Parametric studies were made of the cesium diode with a tantalum emitter and no back emission and operational characteristics were determined in the collision-free region. Work was continued on the vacuum diode generator, with emphasis on the development of Generator 2B. Several significant design changes were made. The sapphire spacer rods were replaced by a peripheral ring support to provide the desired inter-electrode spacing. Preliminary tests indicated that the use of an oxidized molybdenum collector may be sn effective way of attaining and maintaining a collector work function less than 1.9 volts. Studies were began to design an encapsulated Cm/sup 2//sup 4//sup 2/ heat source suitable for fueling the vacuum diode generator. Materials selected to be evaluated for the fuel container were molybdenum, tungsten, and tantalum alloys. (M.C.G.