Preliminary evaluation of the AOS-CsF1 primary frequency standard

We report on operation of a new caesium fountain primary frequency standard at the Astrogeodynamical Observatory of the Polish Space Research Centre. The device was assembled and tested at the National Physical Laboratory in Teddington and subsequently transported to Borowiec where it was fully commissioned in December 2016. We demonstrate its performance in terms of stability in short- and long-term and report preliminary measurements of the systematics effects.