Design Details of FOCS-2, an Improved Continuous Cesium Fountain Frequency Standard

Ferenc Füzesi (1) , Mark Plimmer (1) , Gregor Dudle (1) , Jocelyne Guéna (2) , Pierre Thomann (3)

1 METAS - Swiss Federal Office of Metrology
2 SYRTE - Systèmes de Référence Temps Espace
3 LTF-IMT - Laboratoire Temps Fréquence

We report on the design, construction and current status of FOCS-2, the second continuous fountain microwave cesium frequency standard after FOCS-1. Both incorporate velocity-selective light traps driven by an electrostatic motor. FOCS-2 will take fuller advantage of the continuous fountain approach to gain in shot-noise-limited stability without loss of accuracy via the use of a higher flux. This is obtained via the implementation of a novel slow-atom pre-source and better collimation of the atomic beam. A detailed description of the apparatus is provided and compared with FOCS-1 to highlight improvements. In addition, we present results from related experiments on collimation in a 2D optical lattice. The goals for this new standard are a short-term stability of < 4x10-14 $\tau$-1/2 and a relative frequency uncertainty of < 1 x 10-15.

Keywords: Continuous Atomic Fountain Frequency Standard

Domains: Atomic Physics [physics.atom-ph]

Ferenc Füzesi, Mark Plimmer, Gregor Dudle, Jocelyne Guéna, Pierre Thomann. Design Details of FOCS-2, an Improved Continuous Cesium Fountain Frequency Standard. TimeNav'07- EFTF.IEEE-FCS'07, May 2007, Genève, Switzerland. 6 p. ⟨hal-00165376⟩