| 摘要 |
<p>PURPOSE:To greatly improve the heat efficiency of the captioned cathode, by providing, outside a sleeve, a conical heat-reflecting plate which is concentric with the sleeve, and making the heat rays radiated from the side face of the sleeve to be collected onto the tip part where an electron-radiating part is provided. CONSTITUTION:A conical heat-reflecting plate 20 is open from the lower end part of a heater-inserting side toward the side of a tip part where thermionic- emission substance 3 is provided. And also, the curvature of the cone is decided in such a way that the heat rays 5 radiated from the side face of a sleeve 1 are collected onto the tip part where the thermionic-emission substance 3 is provided. Thereby, the tip part of sleeve 1 is concentrically heated to remarkably enhance the thermal efficiency by a cathode. In this case, the outside face of the sleeve 1 is subjected to a blackening treatment in order to enhance the absorption of the heat rays, and the inside curved surface of the heat-reflecting plate 20 is also subjected to a coating treatment by gold or the like in order to effectively enhance the reflection of the heat rays.</p> |
