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NIST Authors in Bold

Displaying 24476 - 24500 of 73721

Limited Live-time Measurements of Frequency Spectra

July 31, 2011
Author(s)
David A. Howe, Neil Ashby, Danielle G. Lirette, Archita Hati, Craig W. Nelson
Frequency-difference-of-arrival (FDOA) can be used to monitor and track an emitter’s location by observing Doppler frequency shifts of the carrier during short pulsed transmissions. This specific application needs to consider two frequency-stability levels

MOT Loading Enhancement with Stimulated Light Forces

July 31, 2011
Author(s)
Elizabeth A. Donley, Tara C. Liebisch, Eric M. Blanshan, John E. Kitching
We demonstrate atom number enhancement in a magneto-optical trap (MOT) by use of bichromatic cooling to slow an atomic beam that is loaded into a MOT. Bichromatic cooling employs stimulated emission to apply strong cooling forces that are not limited by

Residual PM Noise Evaluation of Radio Frequency Mixers

July 31, 2011
Author(s)
Corey A. Barnes, Archita Hati, Craig W. Nelson, David A. Howe
Direct observation of phase modulated (PM) noise is often difficult due to the high dynamic range that exists between the carrier and the modulated sidebands. A common tool used to reduce the dynamic range is the phase detector, which removes the carrier

Status of a compact cold-atom CPT frequency standard

July 31, 2011
Author(s)
Elizabeth A. Donley, Francois-Xavier R. Esnault, John E. Kitching, Eugene N. Ivanov
We describe the main progress towards the realization of a cold atom frequency standard based on coherent population trapping (CPT). We explain our particular CPT configuration and give details on the experimental setup.

Synchronizing Computer Clocks Using Kalman Filters

July 31, 2011
Author(s)
Judah Levine
I have used the Kalman Filter algorithm to improve the link between the Internet Time Servers operated by the National Institute of Standards and Technology (NIST) and the primary atomic clock ensemble in Boulder, which realizes UTC(NIST) and which is used

Towards an all-digital time scale

July 31, 2011
Author(s)
Stefania Romisch, Steven R. Jefferts, Thomas E. Parker
The implementation of an all-digital time scale is under way at NIST, using a novel 8-channel, all-digital phase measurement system based on subsampling techniques. The phase measurement system is used to compare output signals from several commercial

Update on a Comparison of Cesium Fountain Primary Frequency Standards

July 31, 2011
Author(s)
Thomas E. Parker
An update to a previous long term frequency comparison of cesium fountain primary frequency standards has been made. This update covers the approximate three year interval from March 2008 to March 2011 and also includes two new standards. Also, simulated

Vibration Sensitivity of Optical Components: A Survey

July 31, 2011
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We propose and demonstrate a novel technique to measure the vibration sensitivity of two-port fiber-based optical components. It uses a common-arm counter-propagating frequency-shifted interferometer that cancels the vibration induced phase noise of the

Smart Clocks Have a Hand in the Smart Grid

July 29, 2011
Author(s)
Jeffrey Fletcher, Dhananjay Anand, Maruthi Chaluvadi, Julien M. Amelot, Ya-Shian Li-Baboud, James Moyne
Clock synchronization is becoming an increasingly important characteristic of modern wide area monitoring and control systems such as the power grid. It provides an opportunity to coordinate control actions and measurement instants across hundreds of miles

Lithography and Chemical Modeling of Acid Amplfiers for Use in EUV Photoresists

July 28, 2011
Author(s)
Kirstin Kruger, craig higgins, Gregg M. Gallatin, Robert Brainard
We postulate that the best way to simultaneously improve resolution, line edge roughness (LER), and sensitivity all in EUV resists is to increase the number of acid molecules generated per absorbed photon. In previous work, we showed that acid amplifiers

The sixth industrial fluid properties simulation challenge

July 28, 2011
Author(s)
F Case, Anne M. Chaka, Jonathan D. Moore, Raymond D. Mountain, Richard B. Ross, Vincent K. Shen, Eric A. Stahlberg
The sixth industrial fluid properties simulation challenge was held in 2010. The contestants were challenged to predict mutual solubility in liquid-liquid equilibria (LLE) for the PROGLYDE DMM + water system at various temperatures and atmospheric pressure

Initial Reconnaissance of the 2011 Wildland-Urban Interfaces Fires in Amarillo, Texas

July 27, 2011
Author(s)
Alexander Maranghides, William Mell, Karen Ridenour, Derek McNamara
The National Institute of Standards and Technology (NIST) is working to reduce the risk of fire spread in Wildland-Urban Interface (WUI) communities. An objective of this work is to develop first generation tools for improved risk assessment and risk

Single-Photon Sources and Detectors

July 27, 2011
Author(s)
M D. Eisaman, Jingyun Fan, Alan L. Migdall, Sergey Polyakov
We review the current status of single-photon-source and single-photon-detector technologies operating at wavelengths from the ultraviolet to the infrared. We discuss applications of these technologies to quantum communication, a field that is currently

Unification of universal and non-universal topological quantum computation

July 26, 2011
Author(s)
Haitan Xu, Jacob Taylor
Approaches for implementing primitives for quantum computation using Read-Reyazi anyons remain computational difficult to find. We demonstrate how recently discovered approaches, including composition of anyons and deconstruction of many-qubit operations

A circular dielectric grating for vertical extraction of single quantum dot emission

July 25, 2011
Author(s)
Marcelo I. Davanco, Matthew T. Rakher, Dieter Schuh, Antonio Badolato, Kartik A. Srinivasan
We demonstrate a suspended circular grating composed of partially etched annular trenches in a thin GaAs membrane, designed for e±cient and moderately broadband ( approx. 5 nm) extraction of emission from single InAs quantum dots. Simulations indicate that

A fitting program for molecules with two inequivalent methyl tops and a plane of symmetry at equilibrium. Application to new microwave and millimeter-wave measurements in methyl acetate

July 25, 2011
Author(s)
Marcela Tudorie, Isabelle Kleiner, Jon T. Hougen, Sonia Melandri, Lilian Sutikdja, Wolfgang Stahl
A program for fitting the high-resolution torsion-rotation spectra of molecules having two inequivalent methyl rotors and a plane of symmetry at equilibrium is described and then applied to methyl acetate [CH3-O-C(=O)-CH3]. The G18 permutation-inversion

Magnetic Tunnel Junctions Fabricated Using Ion Neutralization Energy as a Tool

July 25, 2011
Author(s)
Joshua M. Pomeroy, Holger Grube, Pei-Ling Sun, Yun-Che Wang, Russell E. Lake
The neutralization energy of highly charged ions (HCIs) is used as an intermediate processing step to modify the electrical properties of magnetic tunnel junctions (MTJs), providing an additional degree of freedom in the devices’ fabrication. While most

SP250 Spectral Irradiance Calibrations

July 25, 2011
Author(s)
Howard W. Yoon, Charles E. Gibson
This document describes the process of the realization, the maintenance and the dissemination of the spectral irradiance scale and its accompanying uncertainties at the National Institute of Standards and Technology. It describes the measurement procedures

Supplementary comparison CCR(IK)-S2 of standards for absorbed dose to water Co-60 gamma radiation at radiation processing dose levels

July 25, 2011
Author(s)
Marc F. Desrosiers, D T. Burns, P J. Allisy-Roberts, P H. Sharpe, M. Pimpinella, V. Lourenco, Y. L Zhang, A Miller, V Generalova, V. Sochor
Eight national standards or absorbed dose to water in Co-60 gamma radiation at the dose levels used in radiation processing have been compared over the range from 1 kGy to 30 kGy using the alanine dosimeters of the NIST and the NPL as the transfer
Displaying 24476 - 24500 of 73721
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