时间频率基准装置的研制现状

Progress towards primary frequency standard

时间频率基准装置——铯原子喷泉钟,在标准时间产生和保持、基础物理研究中发挥了重要的作用.介绍了铯原子喷泉钟的工作原理,对影响其性能的各项噪声源和频移项给出了分析,影响频率稳定度性能的主要因素为Dick效应相关的原子团装载时间、微波激励源相位噪声和探测激光的频率噪声,影响频率不确定性能主要频移项为:黑体辐射频移、冷原子碰撞频移、腔相位分布频移和微波泄露频移;总结和比较了当前具有先进性能的铯原子喷泉钟采用的技术;介绍了铯原子喷泉钟的主要应用方向、空间冷原子铯钟的研制情况和光学频率原子钟进展.

The cesium fountain clock as primary frequency standard is widely used in the areas, such as time-keeping system, satellite navigation, fundamental physics research, etc. The principle of operation of cesium fountain clock is introduced. The noise source and frequency shift term are ananlyzed. The major noise source influencing frequency stability are cold atom loading time, microwave phase noise related to Dick effect, and detection laser frequency noise. The major frequency bias influencing frequency uncertainty is blackbody radiation frequency shift,cold atom collision frequency shift,distributed cavity phase frequency shift and microwave leakage frequency shift.The key technique to achieve high- performance cesium fountain clock is sumerized. The application of cesium fountain clock is presented. The status of space cesium clock and future primary frequency standard of optical clock are shown.