新型国产光抽运铯钟性能分析

Performance analysis of new domestic laser-pumped cesium atomic clock

关键词:  光抽运铯钟  频率稳定度  相对频率偏差  频率漂移率  可预测性

Key words:  Laser-pumped cesium clock  Frequency stability  Frequency accuracy  Frequency drift rate  Predictability

摘要:

铯钟是高精度守时应用的核心组成部分，其性能直接影响整个守时系统的稳定性和准确性。在介绍铯钟的主要性能指标及评估方法后，对新型TA2000铯钟的频率稳定度、相对频率偏差、频率漂移率及可预测性进行了系统分析。结果表明,新型国产铯钟与进口铯钟相比，中短期稳定度指标更高，长期稳定度与进口铯钟相当，但相对频率偏差和频率漂移率依旧存在差距。具体而言，新型铯钟的相对频率偏差优于6.5×10-13，频率稳定度优于2×10-14/d，频率漂移率优于6.5×10-15/d (开机连续测量32 d结果)；在可预测性方面，新型铯钟5 d预测的均方根误差优于5 ns。对新型国产光抽运铯钟的性能分析，可以为其进入守时钟组体系提供数据参考。

Abstract:

Cesium clocks are the core components of high-precision timekeeping applications, and their performance significantly affects the stability and accuracy of the entire timekeeping system. After introducing the main performance indexes and evaluation methods of cesium clocks, the frequency stability, frequency accuracy, frequency drift rate and predictability of the new TA2000 cesium clock are systematically analysed. The results show that compared with imported cesium clocks, the new domestic cesium clock has higher short-term and medium-term stability, comparable long-term stability, but there's still a gap between the relative frequency deviation and frequency drift of the new domestic cesium clock and that of the imported cesium clock. Specifically, the frequency accuracy of the new cesium clock exceeds 6.5×10-13, while the frequency stability is better than 2×10-14/d, and the frequency drift rate is better than 6.5×10-15/d (results of 32 days of continuous measurement). In terms of predictability, the root mean square error of the 5-day prediction of the new cesium clock is less than 5 ns. The performance analysis of the new domestic optically pumped cesium clock can provide a data reference for its entry into the group system of timekeeping clocks.