Work

Accuracy evaluation of primary frequency standard NIST-F4

Year: 2025

Type: article

Abstract: This work describes the apparatus for NIST-F4, an updated cesium atomic fountain at the National Institute of Standards and Technology (NIST), and presents an accuracy evaluation of the fountain as a primary frequency standard. The fountain uses optical molasses to laser cool a cloud of cesium atoms and launch it vertically in a fountain geometry. In high-density mode, the fractional frequency stability of NIST-F4 is σ y ( τ ) = 1.5 × 10 − 13 / τ , where τ is the measurement time in seconds. The short-term stability is limited by quantum projection noise and by phase noise from the local oscillator, an oven-controlled crystal oscillator operating at 5 MHz. Systematic frequency shifts and their uncertainties have been evaluated, resulting in a systematic (type B) fractional frequency uncertainty σ B = 2.2 × 10 − 16 .

Source: Metrologia

DOI: 10.1088/1681-7575/adc7bd

Authors: Vladislav Gerginov, Gregory W Hoth, Thomas P Heavner, Thomas E Parker, Kurt Gibble, Jeff A Sherman

Institutions: National Institute of Standards and Technology, Pennsylvania State University

Language: English

Topic: Advanced Frequency and Time Standards

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,325

Funders: Directorate for Mathematical and Physical Sciences, National Institute of Standards and Technology