| 摘要 |
PURPOSE:To economically obtain an electron gun whose change of perveance caused by the dimensional ununiformity in the assembly process is small by combining a cathode and a focussing electrode, then correcting the relative position between the cathode and an anode, and fixing the anode. CONSTITUTION:A cathode cylinder 1 is fixed to a focussing electrode 3 through a cathode support body 2 and a cathode frame is assembled. An anode support plate 11, cathode frame support body 6, heater electrode plate 7, electron gun support body 8, and vacuum enclosure ceramics 9a-9d are laminated alternately. Then a vacuum container 10 is assembled by brazing every part on their contact surface. Subsequently, L2 is determined by the L1 value measured when the cathode frame was assembled in such that the variation of perveance due to DELTAL1 which is a deviation of design value L1 is corrected in its characteristics and the support plate 11 of an anode 12 is fixed to the L2 position by welding. As a result, the dimensional ununiformity in the assembly process is absorbed by the post process and the change of perveance can be reduced. |
