NIST F1: Recent improvements and a resulting accuracy of δf/f=0.53x10-15
Thomas P. Heavner, Steven R. Jefferts, Elizabeth Donley, Jon H. Shirley, Tom Parker
In the last several years we have made many improvements to NIST-F1 (a laser-cooled Cs fountain primary frequency standard) resulting in over a factor of 2 reduction in the uncertainty in the realization of the SI second. The two most recent accuracy evaluations of NIST-F1 had combined standard fractional uncertainties of 0.61 x 10-15 (June 2004) and 0.53 x 10-15 (January 2005) which were submitted to the BIPM with total fractional uncertainties (including time transfer contributions) of 0.88 x 10-15 and 0.97 x 10-15 respectively. Here we discuss the improvements, evaluation methods and present an updated uncertainty budget.
Cesium Standards (CES), General Time and Frequency (GEN), Time Scale (Scale), Time/The Second (SEC)
, Jefferts, S.
, Donley, E.
, Shirley, J.
and Parker, T.
NIST F1: Recent improvements and a resulting accuracy of δf/f=0.53x10<sup>-15</sup>, Metrologia, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50098
(Accessed November 28, 2023)