Thorium-Film-Kathode fuer elektrische Entladungsgefaesse

摘要

Or for electric discharge tubes. Support is of high-m.p. metal, particularly W, containing Th oxide and has coating comprising internal layer of tungsten carbide and external layer which is emission base and is high-m.p. metal with thorium migration properties as in Fr. Pat. 1569373 (19.6.68). External layer, particularly Re, is deposited on metallic carbided support which is alloy of W and 5-25% Re.