| 摘要 |
<p>A caesium beam tube used as a frequency standard has an evacuated beam path leading from the caesium beam generator to the detector. The tube contains a rigid case with a cavity (301) oscillating at high frequency composed of a metal block used as a basic support of the tube. The rigid case has at one end, a coaxial connection to a caesium beam generator (1) and a first condition selective magnet (2) and, at the other end a coaxial connection to a second condition selective magnet (6) and a detector (7). The cavity (301), magnetic poles (201A, 201B) of the first and second magnets, the caesium beam generator (1), and the detector (7) define together an evacuated enclosure by themselves. Permanent magnets (207A, 207B) and other related parts (401, 402) are situated outside the enclosure. </p> |
