THERMIONIC ELEMENT FOR LAB6 EMITTER THROUGH CHEMICAL VAPOR DEPOSITION METHOD

摘要

PURPOSE:To use the layer of LaB6 directly in a combustion furnace by forming the layer of LaB6 to the layer of graphite through a chemical vapor deposition method. CONSTITUTION:A hot shell 1, a shell of which is shaped by a coaxial cylindrical type thermionic element, a nose of which is formed to a hemispherical shape, consists of three layer structure of silicon carbide 2, graphite 3 and lanthanum boride (hereinafter called LaB6) 4, and LaB6 4 as an inner surface functions as an emitter. An Ni collector 6 is mounted on the inside of the emitter 4 through a clearance 5, and connected electrically to a collector stem 6' and an airpipe 7. The layer of LaB6 is shaped by evaporating the layer of graphite 3 through a chemical vapor depositon method at that time. Accordingly, the layer of LaB6 4 has excellent denseness, and can also be used in a combustion furnace.