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Search Publications by: Galen O'Neil (Fed)

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Displaying 51 - 73 of 73

Developments in time-division multiplexing of X-ray transition-edge sensors.

December 8, 2015
Author(s)
William B. Doriese, Kelsey M. Morgan, Douglas A. Bennett, Edward V. Denison, Colin P. Fitzgerald, Joseph W. Fowler, Johnathon D. Gard, James P. Hays-Wehle, Gene C. Hilton, Kent D. Irwin, Young Il Joe, John A. Mates, Galen C. O'Neil, Carl D. Reintsema, Nigel O. Robbins, Daniel R. Schmidt, Daniel S. Swetz, Hideyuki Tatsuno, Joel N. Ullom, Leila R. Vale
Time-division multiplexing (TDM) is a mature scheme for the readout of transition-edge sensors. Variants of TDM, which is based on superconducting-quantum-interference-device (SQUID) current amplifiers, have to date been field-deployed in several

Observation of Iron Spin-States using Tabletop X-ray Emission Spectroscopy and Microcalorimeter Sensors

December 2, 2015
Author(s)
Young Il Joe, Galen C. O'Neil, Luis Miaja Avila, Joseph W. Fowler, Kevin L. Silverman, Daniel S. Swetz, Joel N. Ullom, Ralph Jimenez
X-ray emission spectroscopy (XES) is a powerful probe of the electronic and chemical state of elemental species embedded within more complex compounds. X-ray sensors that combine high resolving power and high collecting efficiency are desirable for photon

The Practice of Pulse Processing

November 12, 2015
Author(s)
Joseph W. Fowler, Bradley K. Alpert, William B. Doriese, Young Il Joe, Galen C. O'Neil, Joel N. Ullom, Daniel S. Swetz
The analysis of data from x-ray microcalorimeters requires great care; their excellent intrinsic energy resolution cannot usually be achieved in practice without a statistically near-optimal pulse analysis and corrections for important systematic errors

Microcalorimeter Spectroscopy at High Pulse Rates: a Multi-Pulse Fitting Technique

August 24, 2015
Author(s)
Joseph W. Fowler, Bradley K. Alpert, William B. Doriese, Young Il Joe, Galen C. O'Neil, Cherno Jaye, Joel N. Ullom, Daniel A. Fischer, Daniel S. Swetz
Transition edge sensor microcalorimeters can measure x-ray and gamma-ray energies with very high energy resolution and high photon-collection efficiency. For this technology to reach its full potential in future x-ray observatories, each sensor must be

Macroscopic Subkelvin Refrigerator Employing Superconducting Tunnel Junctions

August 10, 2015
Author(s)
Xiaohang NMN Zhang, Peter J. Lowell, Brandon L. Wilson, Galen C. O'Neil, Joel N. Ullom
In this paper, we demonstrate a general-purpose macroscopic refrigerator based on the transport of hot electrons through superconducting tunnel junctions. Our refrigerator is intended to provide access to temperatures below those accessible using pumped

High-resolution X-ray emission spectroscopy with transition-edge sensors: present performance and future potential

May 1, 2015
Author(s)
W.Bertrand (Randy) Doriese, Joseph Fowler, Daniel Swetz, Cherno Jaye, Daniel A. Fischer, Carl D. Reintsema, Douglas Bennett, Leila R. Vale, Gene C. Hilton, Dan Schmidt, Joel Ullom, Jens Uhlig, Ujjwal Mandal, Galen O'Neil, Luis Miaja Avila, Young I. Joe, wilfrid fullagar, Fredrick P. Gustafsson, Dharma Kurunthu, Villy Sundstrom
X-ray emission spectroscopy (XES) is a powerful element-selective tool to analyze the oxidation states of atoms in complex compounds, determine their electronic configuration, and identify unknown compounds in challenging environments. Until now the low

Sub-100 mK cooling using normal-metal?insulator?superconductor tunnel junctions

December 15, 2013
Author(s)
Peter J. Lowell, Galen C. O'Neil, Jason M. Underwood, Xiaohang NMN Zhang, Joel N. Ullom
Normal-metal∖insulator∖superconductor (NIS) junctions can be used as solid-state refrigerators since the hottest electrons preferentially tunnel from the normal metal into the superconductor. In this paper, we present NIS junctions optimized to cool

Macroscale refrigeration by nanoscale electron transport

February 26, 2013
Author(s)
Peter J. Lowell, Galen C. O'Neil, Jason M. Underwood, Joel N. Ullom
Nano- and Micro- Electromechanical devices (NEMS & MEMS) have become ubiquitous; examples include automobile accelerometers, inkjet printer heads, infrared viewers, and mirrors for image manipulation and projection. Applications fall broadly in the

A high resolution gamma-ray spectrometer based on superconducting microcalorimeters

September 28, 2012
Author(s)
Douglas A. Bennett, Robert D. Horansky, Daniel R. Schmidt, Andrew Hoover, Ryan Winkler, Bradley K. Alpert, James A. Beall, William B. Doriese, Joseph W. Fowler, Gene C. Hilton, Kent D. Irwin, Nathan J. Hoteling, Vincent Y. Kotsubo, John A. Mates, Galen C. O'Neil, Michael W. Rabin, Carl D. Reintsema, Francis J. Schima, Daniel S. Swetz, Leila R. Vale, Joel N. Ullom
Improvements in superconductor device fabrication, detector hybridization techniques, and superconducting quantum interference device readout have made square-centimeter-sized arrays of gammaray microcalorimeters, based on transition-edge sensors (TESs)

Insensitivity of Sub-Kelvin Electron-Phonon Coupling to Substrate Properties

December 16, 2011
Author(s)
Jason M. Underwood, Peter J. Lowell, Galen C. O'Neil, Joel N. Ullom
We have examined the role of the substrate on electron-phonon coupling in normal metal films of Mn-doped Al at temperatures below 1 K. Normal metal-insulator-superconductor junctions were used to measure the electron temperature in thin metal films as a

Al-Mn Transition Edge Sensors for Cosmic Microwave Background Polarimeters

November 22, 2010
Author(s)
Daniel R. Schmidt, Hsiao-Mei Cho, Johannes Hubmayr, Peter J. Lowell, Michael D. Niemack, Galen C. O'Neil, Joel N. Ullom, Ki W. Yoon, Kent D. Irwin, W L. Holzapfel, M Lueker, E M. George, E Shirokoff
Superconducting transition edge sensors (TES) require superconducting films with transition temperatures (Tc)and properties that can be tailored to the particular requirements of individual applications. We have been developing Al-Mn films with a tunable

Al-Mn transition edge sensors for cosmic microwave background polarimeters

November 22, 2010
Author(s)
Daniel R. Schmidt, Hsiao-Mei Cho, Johannes Hubmayr, Peter J. Lowell, Michael D. Niemack, Galen C. O'Neil, Joel N. Ullom, Ki W. Yoon, Kent D. Irwin
Superconducting transition edge sensors (TES) require superconducting films with transition temperatures (Tc)and properties that can be tailored to the particular requirements of individual applications. We have been developing Al-Mn films with a tunable

Quasiparticle Density of States Measurements in Clean Superconducting AlMn Alloys

May 6, 2010
Author(s)
Galen C. O'Neil, Daniel R. Schmidt, Nathan A. Tomlin, Joel N. Ullom
Aluminum doped with Manganese (AlMn) forms a superconducting alloy with the transition temperature suppressed by the added Manganese. We present quasiparticle density of states measurements on superconducting AlMn alloys made by current-voltage

High resolution X-ray transition-edge sensor cooled by tunnel junction refrigerators and operated above the transition temperature

April 21, 2008
Author(s)
Nathan A. Tomlin, Galen C. O\'Neil, James A. Beall, Gene C. Hilton, Kent D. Irwin, Daniel R. Schmidt, Leila R. Vale, Joel N. Ullom
We demonstrate cooling of an X-ray transition-edge sensor (TES) using solid-state refrigerators based on normal-metal / insulator / superconductor (NIS) tunnel junctions. We are able to operate the TES at a bath temperature of 260 mK, which is 75 mK above

Density of states measurements of Al lightly doped with Mn

January 29, 2008
Author(s)
Galen O'Neil, Dan Schmidt, Nathan A. Tomlin, Joel Ullom, Kent D. Irwin, Anthony S. Williams, Gerry Arnold, Steve T. Ruggiero
Al lightly doped with Mn is a tunable superconductor, potentially useful in normalmetal/insulator/superconductor refrigerators. The superconducting transition temperature varies with Mn concentration and the density of states is like a BCS superconductor

Operation of an X-ray transition-edge sensor cooled by tunnel junction refrigerators

January 19, 2008
Author(s)
Nathan A. Tomlin, James A. Beall, Gene C. Hilton, Kent D. Irwin, Galen O'Neil, Dan Schmidt, Leila R. Vale, Joel Ullom
We demonstrate successful cooling of an X-ray transition-edge sensor (TES) using solid-state refrigerators based on normal-metal/insulator/superconductor (NIS) tunnel junctions. Above the TES transition temperature (Tc), we use Johnson noise thermometry to

Multiplexed microcalorimeter arrays for precision measurements from microwave to gamma-ray wavelengths

August 21, 2007
Author(s)
Joel Ullom, W.Bertrand (Randy) Doriese, James A. Beall, William Duncan, S. L. Ferreira, Gene C. Hilton, Rob Horansky, Kent D. Irwin, Terrence J. Jach, John Mates, Nathan A. Tomlin, Galen O'Neil, Carl D. Reintsema, Nicholas Ritchie, Dan Schmidt, Leila R. Vale, Yizi Xu, Barry L. Zink, Andrew Hoover, Clifford R. Rudy, Derek Tournear, Duc Vo, Michael W. Rabin
Cryogenic microcalorimeters are a promising technology for ultrasensitive measurements of electromagnetic radiation from microwave to gamma-ray wavelengths. Cryogenic microcalorimeters derive their exquisite sensitivity from the minimal thermal noise at

Optimization of Transition-Edge Calorimeter Performance

April 15, 2006
Author(s)
Joel N. Ullom, James A. Beall, William B. Doriese, William Duncan, S. L. Ferreira, Gene C. Hilton, Kent D. Irwin, Galen C. O'Neil, Carl D. Reintsema, Leila R. Vale, Barry L. Zink
Calorimeters that exploit the superconducting-to-normal transition are used to detect individual photons from near-infrared to γ-ray wavelengths. Across this wide range, absorption efficiency, speed, and energy resolution are key performance parameters
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