| 摘要 |
<p>PURPOSE:To stabilize the characteristic of electron emission of a cathode throughout a long period, by forming a Ba3 WO6 layer on the surface boundary between a base unit and oxidized material. CONSTITUTION:A cathode base unit is constituted by a flat plate portion 5 and leg portion 4. The cathode base unit is composed of 20-30wt% W and the rest on only Ni. An alkaline earth metal carbonate (Ba, Sr, Ca) CO3 is sprayed to the flat plate portion of the cathode base unit and sealed in an electron tube. The base metal is heated by directly conducting an electric current while being vacuumized the tube to process a firing of the (Ba, Sr, Ca) into (Ba, Sr, Ca) O thus to manufacture a directly-heated cathode.</p> |
