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Search Publications by: James A. Beall (Fed)

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Displaying 51 - 75 of 108

A Time-Domain SQUID Multiplexer System for Read-Out of Superconducting Transition-Edge-Sensor Arrays

July 7, 2003
Author(s)
Carl D. Reintsema, James A. Beall, Steven Deiker, W.Bertrand (Randy) Doriese, Gene C. Hilton, Kent D. Irwin, Sae Woo Nam, Leila R. Vale, Joel Ullom, Yizi Xu, Joern Beyer, Martin Huber
The development of time-domain SQUID multiplexers enables the integration of superconducting transition-edge sensors (TES) into arrays of thousands of elements while maintaining a manageable number of readout channels. The applications for detector arrays

Superconducting Multiplexers for Transition-Edge Sensors

June 1, 2003
Author(s)
Kent D. Irwin, James A. Beall, Joern Beyer, Steven Deiker, W.Bertrand (Randy) Doriese, S. L. Ferreira, Gene C. Hilton, Sae Woo Nam, Carl D. Reintsema, Joel Ullom, Leila R. Vale
Superconducting multiplexers make it possible to build arrays of thousands of low-temperature bolometers and microcalorimeters based on superconducting transition-edge sensors with a manageable number of readout channels. Our first generation SQUID

Surface Micromachining for Transition-Edge Detectors

June 1, 2003
Author(s)
Gene C. Hilton, James A. Beall, Steven Deiker, Joern Beyer, Leila R. Vale, Joel Ullom, Kent D. Irwin
We are developing arrays of high performance detectors based on superconducting transition-edge sensors (TES) for application in x-ray materials analysis as well as x-ray and sub-mm astronomy. In order to obtain the desired thermal time constants, as well

Time-Division SQUID Multiplexers for Transition-Edge Sensors

January 14, 2003
Author(s)
Kent D. Irwin, James A. Beall, Joern Beyer, Steven Deiker, W.Bertrand (Randy) Doriese, S. L. Ferreira, Gene C. Hilton, Sae Woo Nam, Carl D. Reintsema, Joel Ullom, Leila R. Vale
Microcalorimeters and bolometers based on superconducting transition-edge sensors (TES) are important tools for the detection of photons from millimeter waves through gamma rays, and for applications ranging from materials analysis to astronomy. There is a

The Development of Microcalorimeter EDS Arrays

November 1, 2002
Author(s)
Kent D. Irwin, James A. Beall, Steven Deiker, Gene C. Hilton, L. King, Sae Woo Nam, Dale Newbury, Carl D. Reintsema, John A. Small, Leila R. Vale
High-energy-resolution cryogenic microcalorimeters are a powerful new tool for x-ray microanalysis. With demonstrated energy resolution 20 times better than with conventional semiconductor EDS, microcalorimeters are useful in applications such as nanoscale

Transport of Quantum States and Separation of Ions in a Dual RF Ion Trap

September 1, 2002
Author(s)
Mary A. Rowe, A. Ben-Kish, B. DeMarco, D. Leibfried, V. Meyer, James A. Beall, J. Britton, J. Hughes, Wayne M. Itano, Branislav M. Jelenkovic, C. Langer, T. Rosenband, David J. Wineland
We have investigated ion dynamics associated with a dual linear ion trap where ions can be stored in and moved betweenn two distinct locations. Such a trap is a building block for a system to engineer arbitrary quantum states of ion ensembles. Specifically

Resonating torque microbalance for in situ measurements of ferromagnetic films

January 1, 2002
Author(s)
John M. Moreland, James A. Beall, Stephen E. Russek
We describe an instrument for in situ monitoring of the magnetic moment of a thin film during deposition with sub-monolayer sensitivity. The instrument measures the magnetic torque on a film as it is being deposited onto a microcantilever excited near its

Sub-dekahertz spectroscopy of 199 Hg +

September 21, 2001
Author(s)
J. C. Bergquist, R J. Rafac, B. A. Young, James A. Beall, Wayne M. Itano, David J. Wineland
Using a laser that is frequency locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d 106s 2S = (F=0, m f=0) 5d 96s 2 2 d5/2 (F=2, m f=0) electric-quadrupole transition of a single laser-cooled 199Hg + ion stored in a cryogenic

Micromechanical Torque Magnetometer for In Situ Thin-film Measurements

July 1, 2001
Author(s)
John M. Moreland, Albrecht Jander, James A. Beall, Pavel Kabos, Stephen E. Russek
We describe a new type of magnetometer based on a microelectromechanical system (MEMS) for in situ monitoring of magnetic film moment during the film deposition process. The magnetometer measured mechanical torque on a film as it is deposited onto a

Role of Oxygen Pressure during Deposition on the Microwave Properties of YBCO Films

June 1, 1999
Author(s)
David A. Rudman, F. J. Stork, James Booth, J. Y. Juang, Leila R. Vale, G. J. Beatty, C. I. Williams, James A. Beall, Ronald H. Ono, S. B. Qadri, M. S. Osofsky, E. F. Skelton, John H. Claassen, G. Gibson, J. L. MacManus-Driscoll, N. Malde, L. F. Cohen
We have studied the effect of oxygen pressure (PO 2) during pulsed laser deposition on the properties of YBCO films, with particular attention to the low power microwave surface resistance R s.

Simultaneous Optimization of Linear and Nonlinear Microwave Response of YBCO Films

June 1, 1999
Author(s)
James Booth, James A. Beall, David A. Rudman, Leila R. Vale, Ronald H. Ono, Christopher L. Holloway, S. B. Qadri, M. S. Osofsky, E. F. Skelton, J. H. Claasen, G. Gibson, J. L. MacManus-Driscoll, N. Malde, L. F. Cohen
We present results of a systematic study of the effect of film deposition temperture on both the linear and nonlinear response of super-conducting Yba 2Cu 3O7-γ^ (YBCO) thin films and devices at microwave frequencies. Measurements of the unpatterned films

RF Power Dependence Study of Large Area YBCO Thin Films

June 1, 1997
Author(s)
Z Ma, E. I. DeObaldia, G. Hampel, P. A. Polakos, P. M. Mankiewich, B. Batlogg, W. Prusseit, H. Kinder, Angela Anderson, D. E. Oates, Ronald H. Ono, James A. Beall
In an effort to develop HTS superconducting filters with sufficient power handling capability for PCS (Personal Communication Services) base station transmit applications, we have undertaken a study of the power dependence of large area YBCO thin films on

Surface resistance and morphology of YBCO films as a function of thickness

June 1, 1997
Author(s)
F. J. Stork, James A. Beall, Alexana Roshko, Donald C. DeGroot, David A. Rudman, Ronald H. Ono, Jerzy Krupka
We have examined the thickness dependence of the growth morphology and surface resistance Rs of laser ablated YBa 2Cu 3O 7-x films with transition temperatures over 89 K and critical current densities greater than 10 6 A/cm2 at 76 K. The thickness was

A Model of Voltage-Dependent Dieletric Losses for Ferroelectric MMIC Devices

December 31, 1995
Author(s)
J. F. Scott, J. Price, James A. Beall, Ronald H. Ono, C. A. Paz de Araujo, L. D. McMillian
The use of high-dielectric films for microwave devices, especially phased-array radar systems, in the tens of GHz regime requires very low-loss (0.01 to 0.1) films. Unfortunately most ferroelectrics have losses that diverge (greater than unity) in this