| 摘要 |
PURPOSE:To obtain a stable electron emission characteristic while maintaining a fixed interval through the simple constitution by making an elastic body to lie between an insulating base body and a retainer in the cathode structure. CONSTITUTION:A spacer S is interposed into the first grid G followed by housing the cathode structure C in the first grid G so that the insulating base body K3 may make close contact with the spacer S. Thereafter, an elastic body SP such as a spring or the like is interposed into the first grid G, then finally the retainer R presses the cathode structure C through the spring SP while said retainer R is fixed to the first grid G by welding or the like thus making the first grid G to hold the cathode structure C. Thereby, the dimensional scatter in constitution due to external vibration, thermal distortion and thermal expansion can be dissolved thus being able to properly maintain an interval between cathode and the first grid and to obtain a stable radiation current. |
