摘要
目前,SI基本单位“秒”定义是基于铯133超精细能级跃迁频率,该频率处于微波波段。铯原子钟是直接复现秒定义的基准微波原子钟,它从最初的热铯束钟进化到激光冷却铯原子喷泉钟,总不确定度达到了2×10^(-16)。随着喷泉钟技术水平的提高,运行可靠性不断提升,基准微波钟不仅可以校准守时钟,还可以驾驭氢钟作为复合守时钟使用,在时频体系中发挥着重要作用。
Currently,the definition of the SI unit second is based on the cesium-133 hyperfine transition frequency in the microwave range.The primary frequency standards use cesium atomic clocks,which evolved from hot beam clocks to laser-cooled fountain clocks,and the total uncertainty reached 2×10^(-16).The primary microwave clock plays an important role in time and frequency systems,it can be used not only for time keeping clock calibration,but also for steering the hydrogen maser as a time keeping clock with technical progress and reliability improvement.
作者
刘昆
房芳
LIU Kun;FANG Fang(National Institute of Metrology,Beijing 100029,China)
出处
《物理》
CAS
北大核心
2023年第7期441-448,共8页
Physics
关键词
原子钟
基准
喷泉钟
atomic clock
primary standard
fountain clock
