Design of a Compact Φ = π Ramsey Cavity for a Cesium Beam Clock

Summary—To develop a cesium beam clock with smaller size and better frequency stability, we proposed a π-phase-difference Ramsey cavity with a short free-drift region. The cavity operates at the TE107 mode and incorporates a simple electrically excited antenna and a frequency-tuning rod centrally located E-plane of the cavity. Both microwave excitation and frequency tuning occur in the vacuum cesium tube, minimizing external disturbances. This design is applicable to various atomic beam clock configurations employing the Ramsey cavity.