| 摘要 |
A photo-electric cathode comprises alkali metal on a layer of silver bismuth alloy. The ratio of silver to bismuth may be between 80 to 20 and 98 to 2 and is preferably 90 to 10, 92.5 to 7.5, 93.5 to 6.5 or 95 to 5. Alloys of 50 to 50 and 97.5 to 2.5 are stated to give a cathode which is less sensitive. |
