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Search Publications by: Joel Ullom (Fed)

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Displaying 151 - 173 of 173

Measurements & modeling of phonon cooling by electron-tunneling refrigerators

June 1, 2005
Author(s)
Nathan A. Tomlin, A. M. Clark, Anthony Williams, Steve Ruggiero, Gene C. Hilton, James A. Beall, Kent D. Irwin, Leila R. Vale, Joel Ullom
We demonstrate cooling of the electrons and phonons of a silicon nitride Si-N membrane by solid-state refrigerators based on Normal-metal/Insulator/Superconductor (NIS) tunnel junctions. We report a temperature reduction of the Si-N membrane from 260 mK to

Time-division multiplexing of high-resolution TES X-ray microcalotimeters: Four pixels and beyond

November 15, 2004
Author(s)
W.Bertrand (Randy) Doriese, James A. Beall, Steven Deiker, William Duncan, S. L. Ferreira, Gene C. Hilton, Kent D. Irwin, Carl D. Reintsema, Joel Ullom, Leila R. Vale, Yizi Xu
We present experimental results from a four-pixel array of transition-edge-sensor, x-ray microcalorimeters read out through a single amplifier channel via a time-division superconducting quantum interference device multiplexer. We map the dependence of the

Superconducting transition edge sensor using dilute AlMn alloys

July 6, 2004
Author(s)
Steven Deiker, William B. Doriese, Gene C. Hilton, Kent D. Irwin, William H. Rippard, Joel N. Ullom, Leila R. Vale, Steve T. Ruggiero, Anthony Williams, B. Young
We have fabricated a bolometer using a transition-edge sensor (TES) made of Al doped with Mn to suppress the superconducting critical temperature !Tc" of Al from #1 K to #100 mK. The resulting detector exhibits low-frequency noise consistent with theory

Characterization and Reduction of Unexplained Noise in Superconducting Transition-Edge Sensors

May 7, 2004
Author(s)
Joel N. Ullom, William B. Doriese, Gene C. Hilton, James A. Beall, Steven Deiker, William Duncan, S. L. Ferreira, Kent D. Irwin, Carl D. Reintsema, Leila R. Vale
The noise in superconducting Transition-Edge Sensors (TESs) commonly exceeds simple theoretical predictions. The reason for this discrepancy is presently unexplained. We have measured the amplitude and frequency dependence of the noise in TES sensors with

Cryogenics on a Chip

May 3, 2004
Author(s)
Jukka Pekola, Rob Schoelkopf, Joel Ullom
Low-temperature techniques often bring to mind cryogenic liquids, gas compressors, and massive installations. But researchers are now building refrigerators and sensors that work by controlling electrons on a silicon chip.

Robust infrared filters for x-ray spectroscopy

March 11, 2004
Author(s)
Nathan A. Tomlin, Joel Ullom, James A. Beall, Gene C. Hilton, Steven Deiker, W.Bertrand (Randy) Doriese, Kent D. Irwin, Carl D. Reintsema, Leila R. Vale, Yizi Xu
One challenge to using cryogenic detectors for x-ray spectroscopy on a scanning electron microscope is the implementation of infrared blocking filters. In order to achieve high x-ray transmission, these filters can be as thin as 250 nm and consequently are

X-ray Microcalorimeter Arrays Fabricated by Surface Micromachining

March 1, 2004
Author(s)
Gene C. Hilton, James A. Beall, Steven Deiker, Leila R. Vale, W.Bertrand (Randy) Doriese, Joern Beyer, Joel Ullom, Carl D. Reintsema, Yizi Xu, Kent D. Irwin
We are developing arrays of Mo/Cu TES-based detectors for use as as x-ray microcalorimeters and sub-mm bolometers. We have fabricated 8 x 8 pixel x-ray microcalorimeter arrays pixel using surface micromachining techniques. This surface-micromachining

Practical electron-tunneling refrigerator

January 21, 2004
Author(s)
Anna Clark, Anthony Williams, Steve Ruggiero, Marcel L. van den Berg, Joel N. Ullom
We demonstrate a thin-film, solid-state refrigerator based on the removal of hot electrons from a metal by quantum-mechanical tunneling. We have halved the electronic temperature in a macroscopic film from 260 mK to near 130 mK. Both the cooling power and

A Time-Domain SQUID multiplexer for readout of x-ray microcalorimeter arrays

January 1, 2004
Author(s)
W.Bertrand (Randy) Doriese, Jonathan Beall, Joern Beyer, Steven Deiker, S. L. Ferreira, Gene C. Hilton, Kent D. Irwin, John M. Martinis, Sae Woo Nam, Carl D. Reintsema, Joel Ullom, Leila R. Vale
SQUID multiplexers are being developed at NIST for the readout of large arrays of transition-edge-sensor (TES) detectors. Applications for these arrays include x-ray materials analysis on a scanning-electron microscope and astronomical cameras for x-ray

Dilute Al-Mn alloys for superconductor device applications

December 17, 2003
Author(s)
Steve Ruggiero, Anthony Williams, W. H. Rippard, A. Clarke, Steven Deiker, Leila R. Vale, Joel N. Ullom
We discuss results on the superconducting and electron-transport properties of Mn doped Al produced by sputter deposition. The critical temperature of Al has been systematically reduced to below 50 mK by doping with 1000-3000 ppm Mn. Values of the α

Suppression of excess noise in transition-edge sensors using magnetic field and geometry

December 17, 2003
Author(s)
Joel N. Ullom, William B. Doriese, Gene C. Hilton, James A. Beall, Steven Deiker, Kent D. Irwin, Carl D. Reintsema, Leila R. Vale, Yizi Xu
We report recent progress at NIST on Mo/Cu Transition-Edge Sensors (TESs). While the signal- band noise of our sensors agrees with theory, we observe excess high-frequency noise. We describe this noise and demonstrate that it can be heavily suppressed by a

Prototype system for superconducting quantum interference device multiplexing of large-format transition-edge sensor arrays

September 25, 2003
Author(s)
Carl D. Reintsema, Joern Beyer, Sae Woo Nam, Steven Deiker, Gene C. Hilton, Kent D. Irwin, Joel N. Ullom, Leila R. Vale, Michael MacIntosh
We discuss the implementation of a time-division SQUID multiplexing system for the instrumentation of large-format transition-edge sensors (TES) arrays. We cover design and integration issues concerning cryogenic SQUID multiplexers and amplifiers, signal

In-focal-plane SQUID multiplexer

July 11, 2003
Author(s)
Kent D. Irwin, Damian Audley, James A. Beall, Joern Beyer, Steven Deiker, W.Bertrand (Randy) Doriese, William Duncan, Gene C. Hilton, Wayne Holland, Joel Ullom, Leila R. Vale, Yizi Xu
Superconducting quantum interference device (SQUID) multiplexers make it possible to build arrays of thousands of low-temperature microcalorimeters and bolometers based on superconducting transition-edge sensors (TES) with a manageable number of readout

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

Large-Area TKIDs for a New Generation of Neutron Beta Decay Experiments

January 1, 2001
Author(s)
Elizabeth Scott, Jimmy P. Caylor, Maynard S. Dewey, Jiansong Gao, Colin A. Heikes, Shannon Hoogerheide, Hans Pieter Mumm, Jeffrey S. Nico, Joel Ullom, Michael Vissers
Nuclear physics has long played a central role in our efforts to better understand the natural world. Several experiments are well positioned to improve limits in searches for physics Beyond the Standard Model (BSM). Many of the experiments in nuclear