Second generation cesium fountain primary frequency standards at NIST

Abstract

The design of a second-generation cesium-fountain primary frequency standard is being investigated by NIST. It is stated that the proposed design should support a frequency inaccuracy of δf/f 10 -16 and a short-term stability of σ y(τ)≅10 -14/√τ. The stabilities are found to be more than adequate to support frequency transfer systems that are being used. Simultaneous frequency accuracy of δf/f=10 -16, and stability of σ y(τ) ≅ 2×10 -14/√τ should be acheivable with transverse cooling, to support the calibration of optical frequency standards.