| 摘要 |
<p>PURPOSE:To use a hot cathode for a long time without loosing heating characteristic and being broken near an electrode connecting part by providing an electrode having a curved surface making contact with the electrode connecting part on the curved electrode connecting part forming a part of a cylinder. CONSTITUTION:An electrode 14 having a recessed part making contact with the outer surface of a cylindrical thermion emitting cathode 1 and a semi- cylindrical washer 16 having a protruding part making contact with the inner surface are provided. Since the cylindrical form of the cathode 11 can be used as it is without cutting an electrode connecting part 13 as in the past, and the curved surface of the part 13 can be set larger than the curved surface of the electrode in contact, the strength reduction of the part 13 is minimized, compared with a conventional hot cathode body structure, and the breakage by distortion can be prevented. Further, the strength of the part 13 is enhanced by setting the thickness of the part 13 larger than the thickness of a heating part 12, and the breakage by stress caused by the difference in thermal expansion between the cathode 11 and the electrode 14 can be avoided.</p> |
