Microwave Frequency Standard

The main responsibility of the microwave frequency standard laboratory is to develop and operate Cesium fountain clocks which reproduce the current definition of the second. At present, NIM5 fountain clock is the national primary frequency standard with the Type B uncertainty of 0.9E-15. It has been reporting to the BIPM to steer the ETL to generate TAI since 2014. This effort along with the work of UTC (NIM) won the first prize of the National Science and Technology Progress in 2016. The preliminary evaluation of Type B uncertainty of NIM6 Cesium fountain clock reached 0.6E-15, and is expected to reduce to a few parts in 1016. Other research areas including developing ultra-stable microwaves to improve the stability of fountain clocks, and high-precision microwave frequency transmission through commercial optical fibers, providing the stable and accurate time and frequency signals for the research and industries.

NIM5 fountain clock – the national primary frequency standard