A Cold Atomic Beam Ramsey CPT Clock

We have developed a cold atomic beam coherent population trapping clock with the goal of creating a compact, low power device. The clock employs traditional two-zone Ramsey interrogation performed on the D2 line of an atomic beam of
⁸⁷
Rb generated from a 2D+-MOT. The current fractional frequency instability is 2.5 ×10
^-11
τ
^-1/2
. A preliminary evaluation of systematics and noise limiting the current performance is presented.