Preliminary Evaluation of NRC-FCs2 Fountain Clock at the National Research Council Canada

At the National Research Council Canada we are currently performing the first accuracy evaluation of our newly developed caesium fountain clock, NRC-FCs2. This primary frequency standard operates with a short term stability of $\sigma_{\mathbf{y}}(\tau)=1.1\ \mathbf{x}\ 10^{-13}\tau^{-1/2}$ and, upon full evaluation, we expect to achieve a type B uncertainty in fractional frequency below $5\ \mathbf{x}\ 10^{-16}$ . We will discuss the current status of the evaluation, including several evaluated shifts, as well as the outstanding systematics yet to be fully characterized.