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Search Publications

NIST Authors in Bold

Displaying 1376 - 1400 of 2493

Schwere Experimente

November 1, 2015
Author(s)
Stephan Schlamminger, Christian Rothleitner
Obwohl die Standardunsicherheit der Gravitationskonstante in der neuesten Veröffentlichung des CODATA um über die Hälfte reduziert wurde, ist sie noch immer die am ungenauesten bestimmte Naturkonstante.

NIST on a Chip: Realizing SI units with microfabricated alkali vapour cells

October 16, 2015
Author(s)
John E. Kitching, Elizabeth A. Donley, Svenja A. Knappe, Matthew T. Hummon, Argyrios Dellis, Jeffrey A. Sherman, Kartik A. Srinivasan, Vladimir A. Aksyuk, Qiliang Li, Daron A. Westly, Brian J. Roxworthy, Amit Lal
We describe several ways in which microfabricated alkali atom vapour cells might potentially be used to accurately realize a variety of SI units, including the second, the meter, the kelvin, the ampere and the volt, in a compact, low-cost “chip-scale”

Compact atom-interferometer gyroscope based on an expanding ball of atoms

October 12, 2015
Author(s)
Elizabeth A. Donley, John E. Kitching, Stefan Riedl, Gregory W. Hoth, Bruno M. Pelle
We present a compact atom interferometer based on 87Rb atoms that can simultaneously measure rotations and accelerations with a single source of atoms in a 300 cm3 vacuum package.

Measurement of the Microwave Lensing Shift in NIST-F1 and NIST-F2

October 12, 2015
Author(s)
Steven R. Jefferts, Stephan E. Barlow, Thomas P. Heavner, Neil Ashby
We present measurements of the microwave lensing frequency shift in the Primary Frequency Standards (PFS) NIST-F1 and NIST-F2. This frequency bias is reasonably controversial with differing theories giving quite different results. Our measurements are in

Microfabricated Optically-Pumped Magnetometers for Biomagnetic Applications

October 12, 2015
Author(s)
Svenja A. Knappe, John E. Kitching, Orang Alem, Dong Sheng
We report on the progress in developing microfabricated optically-pumped magnetometer arrays for imaging applications. We have improved our sensitivities by several orders of magnitude in the last ten years, Now, our zero-field sensors reach values below

Octave-spanning supercontinuum generation via microwave frequency multiplication

October 12, 2015
Author(s)
Daniel C. Cole, Katja M. Beha, Scott B. Papp, Scott A. Diddams
We demonstrate a system based on telecom components for the generation of an octave-spanning supercontinuum from a continuous-wave laser. The system utilizes direct multiplication of the 10 GHz signal derived from a synthesizer. Pulses are carved from the

Cosolvency and cononsolvency explained in terms of a Flory-Huggins type theory

October 7, 2015
Author(s)
Jack F. Douglas, Jacek Dudowicz, Freed Karl
Standard classic Flory-Huggins (FH) theory is employed to describe the enigmatic cosolvency and co-nonsolvency phenomena for systems of polymers dissolved in mixed solvents. In particular, phase boundaries (spinodals) are calculated for solutions of

Broadly tunable, low timing jitter, high repetition rate optoelectronic comb generator

October 1, 2015
Author(s)
Franklyn J. Quinlan, A. J. Metcalf, Tara M. Fortier, Scott A. Diddams, Andrew M. Weiner
We investigate the low timing jitter properties of a tunable single-pass optoelectronic frequency comb generator. The scheme is flexible in that both the repetition rate and the center frequency can be continuously tuned. When operated at 10 GHz comb

Timekeeping in the Americas

October 1, 2015
Author(s)
Michael A. Lombardi, Jose M. Lopez
Time and its measurement belong to the most fundamental core of physics, and many scientific and technological advances are directly or indirectly related to time measurements. Timekeeping is essential to everyday life, and thus is the most measured

240 Hz linewidth Brillouin laser from a microrod whispering gallery mode resonator

September 29, 2015
Author(s)
William Loh, Aurelien C. Coillet, Frederick N. Baynes, Scott B. Papp, Scott A. Diddams, Joe Becker
We demonstrate an ultra-low noise laser that oscillates based on the stimulated Brillouin scattering nonlinearity in an optical microresonator. Our Brillouin laser employs a microrod resonator whose larger mode volume compared to conventional resonators

Three-level Haldane-like model on a dice optical lattice

September 21, 2015
Author(s)
Ian B. Spielman, T. Andrijauskas, E. Anisimovas, M. Raciunas, A. Mekys, V. Kudriasov, G. Juzeliunas
We consider ultracold atoms in a two-dimensional optical lattice of the dice geometry in a tight-binding regime. The atoms experience a laser-assisted tunneling between the nearest neighbor sites of the dice lattice accompanied by the momentum recoil. This

Precision measurement of the speed of propagation of neutrinos using the MINOS detectors

September 17, 2015
Author(s)
Stefania Romisch, P Adamson, I Anghel, Neil Ashby, A Aurisano, G. Barr, M. Bishai, A. Blake, C. M. Castromonte, S. Childress, M. Christensen, J. A. Coelho, L. Corwin, D. Cronin-Hennessy, J. K. de Jong, A. V. Devan, N. E. Devenish, M. V. Diwan, C. O. Escobar, J. J. Evans, E. Falk, G. J. Feldman, Blair Fonville, M. V. Frohne, H. R. Gallagher, R. A. Gomes, M. C. Goodman, P. Gouffon, N. Graf, R. Gran, K. Grzelak, A. Habig, S. R. Hahn, J. Hartnell, R. Hatcher, Jonathan Hirschauer, A. Holin, J. Huang, J. Hylen, G M. Irwin, Z. isvan, C. James, Steven R. Jefferts, D. Jensen, T. Kafka, S. M. Kasahara, G. Koizumi, M. Kordosky, A. Kreymer, K. Lang, J. Ling, P. J. Litchfield, P. Lucas, W. A. Mann, M. L. Marshak, Demetrios Matsakis, N. Mayer, Angela Mckinley, C. McGivern, M. M. Medeiros, R. Mehdiyev, J Meier, M. D. Messier, W. H. Miller, S. R. Mishra, Stephen Mitchell, S. Moed Sher, C. D. Moore, L. Mualem, J. A. Musser, D. Naples, J. K. Nelson, H. Newman, R. J. Nichol, J. A. Nowak, J. C. O'Conner, M. Orchanian, R. B. Pahlka, J. Paley, Thomas E. Parker, R. B. Patterson, G. Pawloski, A. Perch, S. Phan-Budd, R. K. Plunkett, N. Poonthattatil, Ed Powers, X. Qiu, A. Radovick, B. Rebel, K. Ridl, C. Rosenfeld, H. A. Rubin, M. C. Sanchez, J. Schneps, A. Schreckenberger, P. Schreiner, R. Sharma, A, Sousa, N. Tagg, R, L. Talaga, J. Thomas, M. A. Thomson, X. Tian, A. Timmons, S. C. Tognini, R. Toner, D. Torretta, J. Urheim, P. Vahle, B. Viren, A. Weber, R. C. Webb, C. White, L. Whitehead, L. H. Whitehead, S. G. Wojcicki, J. Wright, Victor S. Zhang, R. Zwaska
We report a two-detector measurement of the propagation speed of neutrinos over a baseline of 734 km. The measurement was made with the NuMI beam at Fermilab between the near and far MINOS detectors. The fractional difference between the neutrino speed and

When does a branched polymer becomes a particle?

September 17, 2015
Author(s)
Alexandros Chremos, Jack F. Douglas
Melts with topologically distinct molecular structures are investigated by molecular dynamics simulation. We determine the mean polymer size and shape, and glass transition temperature for each molecular topology. Both in terms of structure and dynamics

The Osmotic Virial Repersentation of the Free Energy of Polymer Mixing

September 14, 2015
Author(s)
Jack F. Douglas, August W. Bosse
In this Letter we derive a new representation of the free energy of polymer mixing. We begin with a Flory-Huggins-like free energy of mixing, and assume that the excess free energy of mixing exhibits an arbitrary dependence on the blend composition that

Report for Dedicated JPSS VIIRS Ocean Color Calibration/Validation Cruise

September 10, 2015
Author(s)
Bettye C. Johnson, Michael Ondrusek, Eric Stengel, Veronica P. Lance, Menghua Wang, Kenneth Voss, Giuseppe Zibordi, Marco Talone, Zhongping Lee, Jianwei Wei, Junfang Lin, Chuanmin Hu, David English, Charles Kovach, Jennifer Cannizzaro, Alex Gilerson, Sam Ahmed, Amir Ibrahim, Ahmed El-Habashi, Robert Foster, Robert Arnone, Ryan Vandermeulen, Sherwin Ladner, Wesley Goode, Joaquim I. Goes, Helga de Rosario Gomes, Kali McKee, Scott Freeman, Aimee Neeley
The purpose of this cruise aboard the NOAA Ship Nancy Foster was to collect in situ optical and ancillary data for validation of JPSS VIIRS satellite ocean color radiometry and derived products [Wang et al., 2013; Wang et al., 2014]. The project interval

Direct Immersion Annealing of Thin Block Copolymer Films

September 9, 2015
Author(s)
Jack F. Douglas, Alamgir Karim, Arvind Arvind Modi1, Sarang Bhaway, Bryan D. Vogt, Abdullah Al-Enizi, Ahmed Elzatahry, Ashutosh Sharma
We demonstrate that direct immersion annealing (DIA) greatly enhances the rate at which block copolymer (BCP) films order into stable morphologies when the BCP films are immersed in carefully selected mixtures of good and marginal solvents that can impart

A detailed comparison of two continuous GPS carrier-phase time transfer techniques

September 8, 2015
Author(s)
Jian Yao, Judah Levine, Skakun Ivan, Zhiheng Jiang
The wide application of GPS carrier-phase (CP) time transfer is limited by the problem of boundary discontinuity (BD). The discontinuity has two categories. One is "day boundary discontinuity," which has been studied extensively and can be solved by a few

Prospects for atomic clocks based on large ion crystals.

September 8, 2015
Author(s)
John J. Bollinger, Kyle Arnold, Elnur Haciyev, Chern Hui Lee, Eduardo Paez, M. D. Barrett
We investigate the feasibility of precision frequency metrology with large ion crystals. For clock candidates with a negative differential static polarisability, we show that micromotion effects should not impede the performance of the clock. Using Lu+ as
Displaying 1376 - 1400 of 2493
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