title: Primary Atomic Frequency Standards at NIST.
abstract: The development of atomic frequency standards at NIST is discussed and three of the key frequency-standard technologies of the current era are described. For each of these technologies, the most recent NIST implementation of the particular type of standard is described in greater detail. The best relative standard uncertainty achieved to date for a NIST frequency standard is 1.5×10(-15). The uncertainties of the most recent NIST standards are displayed relative to the uncertainties of atomic frequency standards of several other countries.
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: D B
authors: DB
authors: Sullivan
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: J C
authors: JC
authors: Bergquist
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: J J
authors: JJ
authors: Bollinger
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: R E
authors: RE
authors: Drullinger
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: W M
authors: WM
authors: Itano
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: S R
authors: SR
authors: Jefferts
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: W D
authors: WD
authors: Lee
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: D
authors: D
authors: Meekhof
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: T E
authors: TE
authors: Parker
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: F L
authors: FL
authors: Walls
authors: National Institute of Standards and Technology, Boulder, CO 80305-3328.
authors: D J
authors: DJ
authors: Wineland
keywords: atomic clock; atomic frequency standard; cesium-beam frequency standard; cesium-fountain frequency standard; clock; fountain frequency standard; frequency; frequency standard; ion frequency standard; laser-cooling of atoms; stored-ion frequency standard; time