Verfahren und Einrichtung zur Behandlung einer einen Alkalimetalldampf enthaltenden Elektronenroehre, insbesondere einer thermionischen Energiewandlerroehre

摘要

1,011,381. Processing metal-vapour discharge tubes; thermionic generators. RADIO CORPORATION OF AMERICA. Dec.17, 1963 [Dec. 26, 1962], No. 49827/63. Heading H1D. In a method of processing an alkali metal vapour discharge tube, e.g. a thermionic generator, to remove impurity gases, the tube is evacuated and baked to out-gas the parts, and the interior surfaces of the tube are etched with alkali metal vapour while being maintained at a temperature of at least 400‹ K. In particular, the tube may be evacuated either directly, or through a caesium still, first at room temperature and then during heating to at least 800‹ K. During or after bake-out, caesium vapour is present or is introduced into the envelope, e.g. from a sealed capsule, and the interior surfaces of the tube are maintained at a temperature of about 600‹ K, while evacuation is continued through a caesium still. After this etching step, the tube may be sealed off, or may be continuously pumped through a caesium still during operation, a caesium vapour pressure of 1 to 10 mm. of Hg being maintained in the tube. As shown, a caesium-vapour thermionic generator comprises cathode 311 and anode 331 formed by re-entrant metal envelope parts and insulated from one another by ceramic ring 29. A plurality of tubes may be processed and operated simultaneously through a common caesium reservoir and still, Fig. 3 (not shown).