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 by: Susan Schima (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 18 of 18

Next-Generation Chip-Scale Atomic Clocks

October 16, 2023
Author(s)
John Kitching, Matthew Hummon, William McGehee, Ying-Ju Wang, Susan Schima
We describe work toward the development of next-generation chip-scale atomic clocks, which combine small size, low power consumption and manufacturability with high frequency stability. The use of optical transitions in microfabricated vapor cells improves

Atomic flux circuits

February 23, 2020
Author(s)
Douglas Bopp, Ellyse Taylor, Khoa Le, Susan Schima, Matthew Hummon, John Kitching
Atomic vapors are a crucial platform for precision metrology but in their simplest implementation, a thermal vapor, the intrinsic optical resonances are broadened due to the random and isotropic thermal motion of the atoms. By structuring the container of

Chip-scale atomic diffractive optical elements

December 31, 2018
Author(s)
Liron Stern, Douglas G. Bopp, Susan A. Schima, Vincent N. Maurice, John E. Kitching
Atomic systems have long provided a useful material platform with unique quantum properties. The efficient light-matter interaction in atomic vapors has led to numerous seminal scientific achievements including accurate and precise metrology 1-3 and

Propagation and Detection of Radio Signals Before, During, and After the Implosion of a Large Convention Center

October 1, 2006
Author(s)
Christopher L. Holloway, Galen H. Koepke, Dennis G. Camell, Catherine A. Remley, Susan A. Schima, M. McKinley, Robert T. Johnk
In this report, we investigate radio communications problems faced by emergency responders (firefighters and police) in disaster situations such as collapsed buildings. A fundamental challenge to communications into and out of large buildings is the strong

Propagation and Detection of Radio Signals Before, During, and After the Implosion of a Large Sports Stadium (Veterans’ Stadium in Philadelphia)

October 1, 2005
Author(s)
Christopher L. Holloway, Galen H. Koepke, Dennis G. Camell, Catherine A. Remley, Dylan F. Williams, Susan A. Schima, Seturnino Canales
In this report, we investigate radio communications problems faced by emergency responders (firefighters and police) in disaster situation such as collapsed buildings. A fundamental challenge to communications into and out of large buildings is the strong

A current-density scale for characterizing nonlinearity in high-Tc superconductors

June 1, 2005
Author(s)
Kenneth Leong, James C. Booth, Susan A. Schima
In this paper, we characterize microwave nonlinearity in a high temperature superconducting (HTS) thin film sample by measurement of a geometry-independent current-density scale j o. This quanity j specifies the strenth of a material-dependent nonlinearity

Propagation and Detection of Radio Signals Before, During, and After the Implosion of a 13-Story Apartment Building

May 1, 2005
Author(s)
Christopher L. Holloway, Galen H. Koepke, Dennis G. Camell, Catherine A. Remley, Dylan F. Williams, Susan A. Schima, Seturnino Canales, Douglas T. Tamura
In this report we investigate communications problems faced by emergency responders (firefighters and police) in disaster situations (i.e., collapsed buildings). A fundamental challenge to communications into large building structures is the strong

Active Radiometric Calorimeter for Absolute Radioactive Source Calibration

March 2, 2005
Author(s)
Kurt E. Stump, Larry DeWerd, David A. Rudman, Susan A. Schima
This report describes the design and initial noise 'oor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise 'oor of approximately 2 nW. This low noise 'oor is achieved

Zigzag-shaped magnetic sensors

December 13, 2004
Author(s)
Fabio C. da Silva, Willard C. Uhlig, Anthony B. Kos, Susan A. Schima, Joe Aumentado, John Unguris, David P. Pappas
Magnetism in zigzag-shaped thin-film elements is investigated using scanning electron microscopy with polarization analysis, magnetotransport measurements, and micromagnetic simulations. We find that the angle of magnetization alternates along the length

Design and Characterization of a Superconducting Nonlinear Reference Device

December 5, 2003
Author(s)
James Booth, Kenneth Leong, Susan A. Schima, Jeffrey Jargon, Donald C. DeGroot
Abstract ' We describe the design, fabrication, and testing of a nonlinear reference device that has a calculable phase relationship between the fundamental signal and higher harmonic signals in the microwave range. Such a device would be useful for