| 摘要 |
PURPOSE:To improve the multiplication gain of a proximity type image tube and secure its stable working, by preventing a creeping discharge and the leak of current by forming cylindrical insulating structures into convex shapes of which thickness ratio is two times and over. CONSTITUTION:A photoelectric surface 2 formed on the inside of the light incidence plate 1, a microchannel plate 3 magnifying photoelectrons radiated from the surface 2 and a fluorescent screen 5 formed on the inside of photo- output the plate 4 are arranged in a proximity type image tube. The surface 2, the input surface of the plate 3, the output surface of the plate 3 and metallic electrodes 6-9 impressing voltage on the screen 5 are airtightly attached to both ends of insulators 13-15 made of ceramic cylinders by means of brazing or the like repsectively. The structures 13-15 are formed into convex shapes of which thick portions are at least two times as thick as their both end portions respectively. The electrodes 6-9 are arranged so as to locate inwardly from the convex portions of the structures 13-15. Thereby, a creeping discharge and the leak of current can be prevented. |
