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Search Publications by: Joel Ullom (Fed)

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Displaying 101 - 125 of 191

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

Thermal Conductance Engineering for High-Speed TES Microcalorimeters

July 22, 2015
Author(s)
James P. Hays-Wehle, Daniel R. Schmidt, Joel N. Ullom, Daniel S. Swetz
Many current and future applications for superconducting transition-edge sensor (TESmicrocalorimeters require significantly faster pulse-response than is currently available. X-ray spectroscopy experiments at next-generation synchrotron light sources need

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

Measurement of the 240Pu/239Pu Mass Ratio Using a Transition-Edge-Sensor Microcalorimeter for Total Decay Energy Spectroscopy

February 27, 2015
Author(s)
Daniel R. Schmidt, Douglas A. Bennett, James P. Hays-Wehle, Daniel S. Swetz, Joel N. Ullom, Andrew Hoover, Mark Croce, Michael W. Rabin, Evelyn Bond, Terry Holesinger, Gerd Kunde, Laura Wolfsbereg
We have developed a new category of sensor for measurement of the 240Pu/239Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber

Integration of TES microcalorimeters with microwave SQUID multiplexed readout.

December 22, 2014
Author(s)
Douglas A. Bennett, John A. Mates, Johnathon D. Gard, Andrew Hoover, Micheal Rabin, Carl D. Reintsema, Daniel R. Schmidt, Leila R. Vale, Joel N. Ullom
The demonstration of a microwave SQUID multiplexed readout of transition-edge sensor (TES) microcalorimeters has the potential to dramatically expand the scale of arrays of TESs. In this manuscript we discuss recent work to develop an instrument for high

Phase-slip lines as a resistance mechanism in transition-edge sensors

January 27, 2014
Author(s)
Douglas A. Bennett, Daniel R. Schmidt, Daniel S. Swetz, Joel N. Ullom
The fundamental mechanism of resistance in voltage-biased superconducting films is poorly understood despite its importance as the basis of transition-edge sensors (TESs). TESs are utilized in state-of- the-art microbolometers and microcalorimeters

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

Identification and elimination of anomalous thermal decay in gamma-ray microcalorimeters

November 18, 2013
Author(s)
Robert D. Horansky, Douglas A. Bennett, Daniel R. Schmidt, Barry L. Zink, Joel N. Ullom
Microcalorimeter detectors rely on superconducting components and cryogenic temperatures to provide over an order-of-magnitude improvement in energy resolution compared to semiconducting sensors. Resolution improvements impact fields from gamma-ray

High resolution gamma-ray spectroscopy with a microwave-multiplexed TES array

November 11, 2013
Author(s)
Omid Noroozian, John A. Mates, Douglas A. Bennett, Justus A. Brevik, Joseph W. Fowler, Jiansong Gao, Robert D. Horansky, Kent D. Irwin, Daniel R. Schmidt, Joel N. Ullom, Zhao Kang
We demonstrate the first gamma-ray spectroscopy with a microwave-multiplexed two-pixel TES(transition-edge sensor) array. We measured a $^{153}$Gd photon source and achieved an energy resolution of 63 eV full-width-at-half-maximum (FWHM) at 97 keV and an

Lattice damage in superconducting microcalorimeter detectors

June 3, 2013
Author(s)
Robert D. Horansky, Joel N. Ullom, Michael W. Rabin
There is currently significant interest in using superconducting detectors for measurement of ion kinetic energies. Unprecedented resolution is possible with an order of magnitude improvement over semiconductors. Superconducting detectors are now able to

Operation of gamma-ray microcalorimeters at elevated count rates using filters with constraints

May 15, 2013
Author(s)
Bradley K. Alpert, Robert D. Horansky, Douglas A. Bennett, William B. Doriese, Joseph W. Fowler, Andrew Hoover, Michael W. Rabin, Joel N. Ullom
We introduce a filter construction method for pulse processing that differs in two respects from that in standard optimal filtering, in which the average pulse shape and noise power spectral density are combined to create a convolution filter for

Table-top ultrafast x-ray microcalorimeter spectrometry for molecular structure

March 26, 2013
Author(s)
Jens (. Uhlig, William B. Doriese, Joseph W. Fowler, Daniel S. Swetz, Carl D. Reintsema, Douglas A. Bennett, Leila R. Vale, Gene C. Hilton, Kent D. Irwin, Joel N. Ullom, Ilari Maasilta, Wilfred Fullagar, Niklas Gador, Sophie Canton, Kimmo Kinnunen, Villy Sundstrom
This work presents an x-ray absorption measurement by use of ionizing radiation generated by a femtosecond pulsed laser source. The spectrometer was a microcalorimetric array whose pixels are capable of accurately measuring energies of individual radiation

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

Current Distribution and Transition Width in Superconducting Transition-Edge Sensors

December 13, 2012
Author(s)
Daniel S. Swetz, Douglas A. Bennett, Daniel R. Schmidt, Joel N. Ullom
Present models of the superconducting-to-normal transition in transition-edge sensors (TESs)do not describe the current distribution within a biased TES. This distribution is complicated by normal-metal features that are integral to TES design. We present

Observation of bias-specific telegraph noise in large transition-edge sensors

December 11, 2012
Author(s)
Vincent Y. Kotsubo, Douglas A. Bennett, Mark Croce, Michael W. Rabin, Daniel R. Schmidt, Joel N. Ullom
We have observed anomalous random telegraph noise in discrete regions of voltage bias throughout the superconducting transition in larger transition-edge sensors (TESs). The bimodal nature of these noise features is consistent with thermally activated

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)

A two-fluid model for the transition shape in transition-edge sensors

May 1, 2012
Author(s)
Douglas A. Bennett, Daniel S. Swetz, Robert D. Horansky, Daniel R. Schmidt, Joel N. Ullom
Superconducting microcalorimeters based on transition-edge sensors (TESs) are being successfully used in applications ranging from optical photon counting to gamma-ray and alpha particle spectroscopy. Practical instruments often require a complex
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