| 摘要 |
PURPOSE:To extremely minimize deterioration in a secondary electron multiplica tion ratio due to use while being simple to manufacture by forming the secon dary electron emission surface while oxidizing the surface of an aluminum metal. CONSTITUTION:The secondary electron emission surface is formed on the inside walls 1a-4a of the diodes 1-4. Said secondary electron emission surface is formed by oxidizing the surface of an aluminum metal. Said aluminum metal is formed on a nickel plate by vacuum evaporation. Next, the secondary electron emission surface is incorporated inside an airtight container 10 while evacuating the container 10 followed by forming a photoelectric surface 7 where antimony, natrium, potassium and cesium are vacuum-evaporated on the inside wall of an incident window 5. The vacuum evaporation sources 15 and 16 are provided between an electrode 6 for focusing and the window 5 while being vacuum- evaporated by conduction or high frequency heating. In this way, the deteriora tion in the secondary electron multiplication ratio due to use can be made extremely small while being simple to manufacture. |
