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.
Erich N. Grossman, Charles Dietlein, Jon E. Bjarnason, Mabel Ramirez, M. Leivo, J. A. Penttila, P. Helisto, A. Luukanen
We present ultrawideband imagery obtained with modular, 8-element, superconducting Nb microbolometer arrays. Conically scanned images are presented and compared with raster-scanned images obtained on the same arrays and from similar NbN arrays at VTT
Daniel C. van der Laan, Justin Schwartz, Bennie ten Haken, M Dhalle, Hans J. van Eck
An extensive overview of a model that describes current flow and dissipation in high-quality Bi 2Sr 2Ca 2Cu 3O x superconducting tapes is provided. The parallel path model is based on a superconducting current running in two distinct parallel paths. One of
William H. Rippard, Matthew R. Pufall, Michael L. Schneider, Kevin Garello, Stephen E. Russek
We report on the precessional dynamics in spin transfer oscillators having Co 60Fe 20B 20 free layers as a function of annealing time at 225 °C. Repeated annealing reduces the critical current I c by roughly a factor of 3 and increases the tunability of
Stephen E. Russek, David P. Pappas, Sean Halloran, Lu Yuan, Sy-Hwang Liou, Rui Zhang
The minimum detectable field of magnetoresistive sensors is limited by their intrinsic noise. Magnetization fluctuations are one of the crucial noise sources and are related to the magnetization alignment at the antiferromagnetic – ferromagnetic interface
In July, 1951, Ben Warriner (chairman, 1952-1953) circulated a petition to begin the Microwave Theory and Techniques Society under the auspices of the Institute of Radio Engineers. Despite an initial lack of support from the IRE, the roots of the
Nathan D. Orloff, James C. Booth, Makoto Murakami, Ichiro Takeuchi
We demonstrate a novel experimental technique to measure the complex permittivity function of dielectric thin films over the frequency range from 100 Hz to 40 GHz. We apply this technique to determine the broadband permittivity function for ferroelectric
S. Niyomsoan, P. Termsuksawad, Ronald B. Goldfarb, David Olson, B. Mishra, Z Gavra, V I. Kaydanov
The magnetic susceptibility and thermoelectric power of Zr 0.9Ti 0.1Cr xFe 2-x intermetallic compounds were investigated as functions of hydrogen content. The alloys are all paramagnetic, with magnetic susceptibility and Seebeck coefficient increasing with
Imaging and spectroscopy at terahertz frequencies have great potential for healthcare, plasma diagnostics, and homeland security applications. Terahertz frequencies correspond to energy level transitions of important molecules in biology and astrophysics
Fabio C. da Silva, Sean Halloran, Anthony B. Kos, David P. Pappas
We present the design and fabrication of a magentoresistive imaging system capable of measuring 256 channels simultaneously along linear ranges of 4 mm and 13 mm. The channels are interfaced by custom electronics and the images are displayed in real time
Fabio C. Da Silva, Sean Halloran, Anthony B. Kos, David P. Pappas
We present the design and fabrication of a magnetoresistive imaging system capable of scanning 256 channels simultaneously along linear ranges of either 4 or 13 mm. High speed electronics read the channels and transfer the data to a computer that builds
Robert R. Owings, Fabio C. Da Silva, David P. Pappas
This paper presents the results of an interlaboratory comparison and development of a magnetic moment reference material. The comparison was between the National Institute of Standards and Technology, magnetometer manufacturers, industrial, academic, and
Results are presented for simulations of a verification process for noise-parameter measurements. The verification process consists of first measuring separately both a passive device and the amplifier or transistor of interest (the DUT) and then measuring
Michael Schneider, Justin Shaw, Anthony B. Kos, Thomas Gerrits, Thomas J. Silva, Robert McMichael
The spin dynamics of sub-100 nm Ni80Fe20 nanomagnets are directly measured using the magneto-optic Kerr effect and a broadband detection scheme. Elliptical dots approximately 68nm in diameter and 10 nm thick were fabricated in 20x20υm^2^ arrays. There is
We present a new digital-signal-processor-based resonance tracking system for scanned probe microscopy (SPM) imaging. The system was developed to enable quantitative imaging of mechanical properties with nanoscale spatial resolution at practical data
We discuss the sources of uncertainty in near-field measurements and their impact on far-field antenna parameters. The methods of estimating these uncertainties can be considered in three broad categories: theoretical estimation (analytical), computer
We examine the calibration of polarimetric radar cross section measurement systems using a rotating dihedral and a cylinder. Stringent requirements on the polarimetric system's stability, dynamic range and sensitivity as functions of the cross-polarimetric
James P. Sumner, Richard Conroy, Eric Shapiro, John M. Moreland, Alan P. Koretsky
Iron oxide particles are becoming an important contrast agent for magnetic resonance imaging (MRI) cell tracking studies. Simultaneous delivery of fluorescence indicators with the particles to individual cells offers the possibility of correlating optical
In VNA measurements, the magnitude and phase of a transmitted or reflected wave are measured relative to that of the incident wave. VNA measurements are made a single frequency at a time and each frequency component is acquired relative to the internally
Zhandos Utegulov, Justin Shaw, B. T. Draine, S. A. Kim, Ward L. Johnson
Enhancement of Brillouin light scattering (BLS) at the wavelength of 532 nm was observed from Rayleigh-like and Sezawa-like acoustic modes of alkaline-earth bror-aluminosilicate glass covered with periodic arrays of gold nanodisks. This enhancement is
Michael Schneider, Thomas Gerrits, Anthony B. Kos, Thomas J. Silva
We adapted a time-resolved magneto-optic microprobe for use with the pulsed inductive microwave magnetometer apparatus, allowing us to measure the magnetization dynamics of a thin Permalloy film at micrometer and millimeter length scales under exactly the
James P. Randa, Eyal Gerecht, Dave K. Walker, Amanda Cox, Dazhen Gu, Lixing You, Robert L. Billinger
The Noise Project in the Electromagnetics Division of the National Institute of Standards and Technology (NIST) has proposed the development of standards for microwave brightness temperature, for use in remote-sensing applications such as satellite-based
This report on RFID chip-level security is written to help both technical and non-technical audiences navigate the complex chip-level security features of RFID smart cards and tags, and make intelligent security choices. The report explores both attacks
Imaging and spectroscopy at terahertz frequencies have great potential for healthcare, plasma diagnostics, and homeland security applications. Terahertz frequencies correspond to energy level transitions of important molecules in biology and astrophysics
Dennis G. Camell, Robert Johnk, David R. Novotny, Chriss A. Grosvenor
This paper demonstrates the usefulness of time-domain processing to determine free-space antenna factors (FSAF) for electromagnetic compatibility (EMC) antennas. Our procedures are explained and data are provided for frequencies from 30 MHz to 9GHz. We