An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Michael A. Lombardi, Andrew N. Novick, Jose M. Lopez, Jean-Simon Boulanger, Raymond Pelletier
The Inter-American Metrology System (SIM) consists of national metrology institutes in 34 member nations located throughout North, Central, and South America
Two-Way Satellite Time and Frequency Transfer (TWSTFT) has become an important component in the international system for comparing time and frequency over long
Steven R. Jefferts, Jon H. Shirley, Neil Ashby, Thomas P. Heavner, Elizabeth A. Donley, F Levi
We show that the frequency bias caused by distributed cavity phase has a strong dependence on microwave power. We also show that frequency biases associated
Elizabeth A. Donley, Thomas P. Heavner, John O'Brien, Steven R. Jefferts, F Levi
We have successfully cooled and launched cesium atoms in the (1,1,1) atomic fountain geometry at temperatures as low as 0.8 mK. This corresponds to a mean
Archita Hati, Craig Nelson, J Nava, David A. Howe, Fred L. Walls, Huascar Ascarrunz, Justin Lanfranchi, Bill Riddle
We discuss the performance of a W-band (92-96) GHz amplitude modulated (AM) and phase modulated (PM) noise measurement system. The system uses two nearly
David A. Howe, Justin Lanfranchi, Lauren Cutsinger, Archita Hati, Craig Nelson
We present data which shows correlations between phase fluctuations in a low g-sensitive 10 MHz oven-controlled quartz oscillator (OCXO) and acceleration
his study compares the phase noise of different classes of oscillators and amplifiers that work at X-band. Best-in-class results are presented based on recent
The flow impedance of an inertance tube 5.74 mm inside diameter and 2.36 m long coupled to various reservoir volumes was measured and compared with that
System identification methods are presented for the estimation of the characteristic frequency of an optically trapped particle. These methods are more amenable
We present a systematic experimental study of generating correlated photon pairs using a reversed degenerate four-wave mixing process. By overlapping a pair of
J S. Stephens, Tithi Dutta Roy, Joy P. Dunkers, Aarti Rege, J Kohn
A library of tyrosine-derived polycarbonates of have been developed that share a structurally identical backbone with a rich chemical and structural diversity
The gain of four-wave mixing and the gain of Raman scattering in an optical fiber are not uniform with wavelength. Through systematic experimental study, we
Elizabeth Donley, M O. Tataw, F Levi, Steven R. Jefferts, Thomas P. Heavner
We present results on the performance of two important subsystems for NIST -F2 -the second-generation atomic fountain clock at NIST. Firstly, we demonstrate the
Yuqin Zong, Steven W. Brown, Bettye C. Johnson, Keith R. Lykke, Yoshihiro Ohno
Spectrographs are used in a variety of applications in the field of remote sensing for radiometric measurements due to the benefits of measurement speed
J. R. Beveridge, Geof H. Givens, Bruce A. Draper, P. Jonathon Phillips
This paper introduces linear models (LM), generalized linear models (GLM), and generalized linear mixed models (GLMM) for analyzing performance of face
Sumanth B. Chikkamaranahalli, R. R. Vallance, Bradley N. Damazo, Richard M. Silver, James D. Gilsinn
Techniques based on scanning probe microscopy (SPM) are used to fabricate surface structures with dimensions ranging from 10 - 100mm. These structures have been
Talapady N. Bhat, Yadu D. Tewari, H Rodriguez, Robert N. Goldberg
Federal agencies, academia and industries have invested heavily in the development of structural and biothermodynamics data. However, the data are still largely
By means of concrete examples, we discuss the determination of an uncertainty budget for calibration of thermocouples by comparison techniques. In the first
John E. Kitching, Svenja A. Knappe, Li-Anne Liew, John Moreland, Hugh Robinson, P Schwindt, V Shah, Vladislav Gerginov, Leo W. Hollberg
We describe recent efforts to develop microfabricated atomic frequency references capable of supporting a wide variety of commercial and military systems such
A spectrally tunable light source using a large number of LEDs and an integrating sphere has been designed and constructed at the National Institute of
Jeremy Kasdin, Ruslan Belikov, James A. Beall, Robert J. Vanderbei, Michael G. Littman, Michael Carr, Amir Give''on
Current plans call for the first Terrestrial Planet Finder mission, TPF-C, to be a monolithic space telescope with a coronagraph for achieving high contrast
Michael H. Francis, Ronald C. Wittmann, Jin-Seob Kang
A general approach is presented for estimating uncertainties in far-field parameters obtained from spherical near-field antenna measurements. The error is
Steven D. Hudson, J Cabral, Wenhua Zhang, Jai A. Pathak, Kathryn L. Beers
Immiscible fluids find diverse applications, yet their interfacial tension σ remains a fundamental property that governs their performance. Therefore, accurate
Svenja A. Knappe, P Schwindt, Vladislav Gerginov, V Shah, Hugh Robinson
We describe recent research at NIST directed towards the development of microfabricated atomic clocks and magnetometers based on coherent population trapping
As defined by the International Temperature Scale of 1990 (ITS-90), the gallium melting-point cell (29.7646 C) is used in the calibration of standard platinum
At the National Institute of Standards and Technology (NIST), the ITS-90 calibration of standard platinum resistance thermometers (SPRTs) is performed in the
Coatings can be classified by either their appearance, such as glitter, or by their function, such as corrosion protection. However, pigments are currently
Jack A. Stone Jr., Balasubramanian Muralikrishnan, John R. Stoup
We report on performance of a new form of fiber probe, which can be used in conjunction with a coordinate measuring machine (CMM) for microfeature measurement
A number of methods have been proposed to evaluate the reference value for intercomparisons of laboratory measurements. Methods for establishing the reference