| 释义 |
cesium fountain cesium fountain[¦sēz·ē·əm ′fau̇nt·ən] (atomic physics) A device for performing highly accurate frequency measurements, in which cesium atoms are cooled and trapped by pairs of counterpropagating tuned laser beams and are thrown upward by shifting the frequency of the vertical lasers; they are further cooled and placed in one of the hyperfine states, and then pass through a microwave field region before falling into a detection region. |