U.S. flag

An official website of the United States government

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.

Search Publications

NIST Authors in Bold

Displaying 1926 - 1950 of 2503

NMR Characterization of the Formation Kinetics and Structure of Di-O-Benzylidene Sorbitol Gels Self-Assembled in Organic Solvents

January 19, 2011
Author(s)
David L. VanderHart, Jack F. Douglas, Steven Hudson, Joseph M. Antonucci, Elizabeth A. Wilder
The molecule 1,3:2,4-Di-O-Benzylidene sorbitol (DBS) is a common gelator that forms thermally reversible gels in diverse organic solvents. Solid state 13C and proton NMR techniques, along with electron microscopy, are utilized in an exploratory study of

EUV Spectral Lines of Highly-Charged Hf, Ta and Au Ions Observed with an Electron Beam Ion Trap

January 12, 2011
Author(s)
Ilija Draganic, Yuri Ralchenko, Joseph Reader, John D. Gillaspy, Joseph N. Tan, Joshua M. Pomeroy, Samuel M. Brewer, Dmitry D. Osin
Extreme ultraviolet spectra of highly charged hafnium, tantalum, and gold were produced with an electron beam ion trap (EBIT) at the National Institute of Standards and Technology (NIST) and recorded with a flat-field grazing-incidence spectrometer in the

NIST Time and Frequency Bulletin

January 5, 2011
Author(s)
Petrina C. Potts
The Time and Frequency Bulletin provides information on performance of time scales and a variety of broadcasts (and related information) to users of the NIST services.

Femtotesla atomic magnetometry in a microfabricated vapor cell

December 20, 2010
Author(s)
William C. Griffith, Svenja A. Knappe, John Kitching
We describe an optically pumped 87Rb magnetometer with 4.5 fT/Hz 1/2 sensitivity when operated in the spin-exchange relaxation free (SERF) regime. The magnetometer uses a microfabricated vapor cell, consisting of a cavity etched in a 1 mm thick silicon

Progress at NIST in measuring the D-lines of Li isotopes using an optical frequency comb

December 20, 2010
Author(s)
Clayton Simien, Samuel M. Brewer, Joseph N. Tan, John D. Gillaspy, Craig J. Sansonetti
Precise spectroscopic experiments with light atoms can provide information about nuclear properties that are very difficult to obtain in electron scattering experiments. For example, relative nuclear radii of low-Z isotopes can be determined accurately

Polarized neutron beam properties for measuring parity-violating spin rotation in liquid He4

December 14, 2010
Author(s)
A M. Micherdzinska, C. D. Bass, T. D. Bass, K. F. Gan, D Lou, D M. Markoff, Hans Pieter Mumm, Jeffrey S. Nico, A. K. Opper, E I. Sharapov, M Snow, H E. Swanson, V Zhumabekova
Measurements of parity-violating neutron spin rotation can provide insight into the poorly nderstood nucleon-nucleon weak interaction. Because the expected rotation angle per unit length is small (10−7 rad/m), several properties of the polarized cold

An optical frequency comb for infrared spectrograph calibration

November 17, 2010
Author(s)
Gabriel G. Ycas, Franklyn J. Quinlan, Steve Osterman, Gillian Nave, Craig J. Sansonetti, Scott A. Diddams
Detection of extrasolar planets by measurement of the stellar radial velocity shift requires high resolution spectroscopy with long term stability. Presently, the primary wavelength standards in the NIR are NePt and ThAr lamps and absorption cells. These

A Portable Rubidium Fountain

November 15, 2010
Author(s)
Paul D. Kunz, Steven R. Jefferts, Thomas P. Heavner
We are developing a transportable laser-cooled rubidium (Rb) atomic fountain frequency standard. Over the last year we have built the Ramsey cavity and rubidium source oven and are preparing to assemble the physics package. We have also made numerous

NIST F1 and F2

November 15, 2010
Author(s)
Thomas P. Heavner, Thomas E. Parker, Jon H. Shirley, Paul D. Kunz, Steven R. Jefferts
The National Institute of Standards and Technology operates a cesium fountain primary frequency standard, NIST-F1, which has been contributing to International Atomic Time (TAI) since 1999. During the intervening 11 years we have improved NIST-F1 so that

On-Board GPS Clock Monitoring for Signal Integrity

November 15, 2010
Author(s)
Marc A. Weiss, Pradipta Shome, Ron Beard
Navigation signal integrity is paramount for aviation and safety of life services. Hitherto GPS signal anomaly alerting has been provided primarily by ground based augmentations. Significantly improved navigation signal integrity and quality may be

Decoherence due to elastic Rayleigh scattering

November 12, 2010
Author(s)
Hermann Uys, Michael J. Biercuk, Aaron Vandevender, Christian Ospelkaus, Dominic Meiser, R. Ozeri, John Bollinger
We present theoretical and experimental studies of the decoherence of hyperfine ground-state superpositions due to elastic Rayleigh scattering of off-resonant light. We demonstrate that under appropriate conditions, elastic Rayleigh scattering can be the

Collective atomic recoil motion in short-pulse matter-wave superradiance

November 11, 2010
Author(s)
Lu Deng, Edward W. Hagley
We show that a Bragg resonance is substantially incapacitated in short-pulse, matter-wave superradiant scatterings and both positive- and negative-order scatterings contribute equally.We further show that propagation gain is small and scattering events

A Microwave Study of Hydrogen-Transfer-Triggered Methyl-Group Rotation in 5-Methyltropolone

November 10, 2010
Author(s)
Vadim V. Ilyushin, Emily A. Cloessner, Yung-Ching Chou, Laura B. Picraux, Jon T. Hougen, Richard Lavrich
We present here the first experimental and theoretical study of the microwave spectrum of 5-methyltropolone, which can be visualized as a 7-membered aromatic carbon ring with a five-membered hydrogen-bonded cyclic structure at the top and a methyl group at

Electron ionization and gas-phase ion molecule reactions of methylcyclohexane

November 9, 2010
Author(s)
C. Q. Jiao, Karl Irikura, S, F. Adams, A Garscadden
Absolute cross sections for electron impact ionization of methylcyclohexane (MCH, C 7H 14) are measured as a function of the electron energy in a range of 10 to 200 eV. The reactions between selected hydrocarbon ions with MCH, mainly via hydride transfer

Consistency of atomic data for the interpretation of beam emission spectra

November 8, 2010
Author(s)
E. Delabie, M. Brix, R. J. Jasper, C. Giroud, O. Marchuk, M. G. O'Mullane, Yuri Ralchenko, E Surrey, M. G. von Hellermann, K. Zastrow, JET-EFDA Contributors
Several collisional-radiative (CR) models \citeanderson,hutchinson,marchuk:htpd} have been developed to calculate the attenuation and the population of excited states of hydrogen or deuterium beams injected into tokamak plasmas. The datasets generated by

Effect of metal/substrate interfaces on radio-frequency loss in superconducting coplanar waveguides

November 8, 2010
Author(s)
David S. Wisbey, Jiansong Gao, Fabio C. da Silva, Jeffrey S. Kline, Michael Vissers, David P. Pappas, Leila R. Vale
Microscopic two-level systems (TLSs) are known to contribute to loss in resonant superconducting microwave circuits. This loss increases at low power and temperatures as the TLSs become unsaturated. We find that the loss is dependent on both the substrate

Nuclear Magnetic Resonance Gyroscopes

November 2, 2010
Author(s)
Elizabeth A. Donley
Nuclear magnetic resonance gyroscopes(NMRGs)detect rotation as shift in the Larmor precession frequency of nuclear spins. A review of the open literature on NMRGs is presented, which includes an introduction to the spectroscopic techniques that enable

A comprehensive analysis of the spectrum of Fe II

October 28, 2010
Author(s)
Gillian Nave
A new analysis of the laboratory spectrum of Fe II is described. The aim is to produce a comprehensive list of Fe II lines, based on high-resolution grating and Fourier transform spectra, covering wavelengths from 900 ̊A to 5.5 μm. Particular attention has
Displaying 1926 - 1950 of 2503
Was this page helpful?