The caesium fountain clock at the NRC.

Atomic clocks form the foundation of international timekeeping and synchronization. At the National Research Council Canada, the NRC-FCs2 fountain clock has been run nearly continuously with minimal interruption since 2020, participating in the steering of International Atomic Time through regular submissions of data to the International Bureau of Weights and Measures. We describe the design and performance of NRC-FCs2, a caesium fountain clock serving as a primary frequency standard for Canada, and its role in global timekeeping. [ABSTRACT FROM AUTHOR]