| 摘要 |
PURPOSE:To improve efficiency of an electron gun by emitting an electron beam so that its intensity can be easily adjusted. CONSTITUTION:A plurality of internal apertures 20 are provided between apertures 13, provided so as to protrude in an ionizing chamber 3, in both ends of an outlet window 10 and a conductive extraction grid 11. Further, these internal apertures 20 are mounted to the above-mentioned outlet window 10 and conductive extraction grid 11 and arranged so as to protrude into the ionizing chamber 3. In this way, intensity of an electron beam is easily adjusted. |
