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Search Publications by: Joel Ullom (Fed)

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Displaying 151 - 175 of 356

Beating Darwin-Bragg losses in lab-based ultrafast x-ray experiments

March 24, 2017
Author(s)
Wilfred Fullagar, Jens Uhlig, Ujjwal Mandal, Dharma Kurunthu, Amal El Nahhas, Hideyuki Tatsuno, Alireza Honarfar, Fredrik Gustafsson, Villy Sundstrom, Mikko Palosaari, Luis Miaja Avila, Young I. Joe, Daniel Swetz, Joel Ullom
The use of low temperature thermal detectors for avoiding Darwin-Bragg losses in lab-based ultrafast experiments has begun. An outline of the background of this new development is offered, showing the relevant history and initiative taken by this work.

Ultrafast time-resolved x-ray absorption spectroscopy of ferrioxalate photolysis with a laser plasma x-ray source and microcalorimeter array

February 17, 2017
Author(s)
Galen C. O'Neil, Joel N. Ullom, Luis Miaja Avila, Young Il Joe, Joseph W. Fowler, Carl D. Reintsema, Daniel S. Swetz, Kevin L. Silverman, Daniel R. Schmidt, Bruce D. Ravel, Gene C. Hilton, William B. Doriese, Bradley K. Alpert, Ralph Jimenez
Using a table-top apparatus based upon a laser plasma x-ray source and an array of cryogenic microcalorimeter x-ray detectors, we have measured the transient x-ray absorption spectrum during the ferrioxalate photoreduction reaction. We observe the Fe K

Compact 2.2 K Cooling System for Superconducting Nanowire Single Photon Detectors

January 25, 2017
Author(s)
Vincent Y. Kotsubo, Ray Radebaugh, Sae Woo Nam, Joel N. Ullom, Brandon L. Wilson, Paul Hendershott, Micheal Bonczyski
We are developing a compact, low power, closed cycle cooling system for Superconducting Nanowire Single Photon Detectors. The base temperature of the present prototype, which uses a helium-4 Joule-Thomson stage, is 2.2 K with over 1.2 mW of cooling. This

An Overhanging Absorber for TES X-ray Focal Planes

December 23, 2016
Author(s)
James P. Hays-Wehle, Peter J. Lowell, Daniel R. Schmidt, Daniel S. Swetz, Joel N. Ullom
In order to improve pixel count and collecting area, future TES x-ray focal planes require pixels with both a higher coverage of the active area and compatibility with in-focal-plane multiplexing. We anticipate these improvements by developing a pixel with

When "Optimal Filtering" Isn't

December 7, 2016
Author(s)
Joseph Fowler, Bradley Alpert, W.Bertrand (Randy) Doriese, James P. Hays-Wehle, Young I. Joe, Kelsey Morgan, Galen O'Neil, Joel Ullom, Dan Schmidt, Daniel Swetz
The so-called ''optimal filter'' analysis of a microcalorimeter's x-ray pulses is statistically optimal only if all pulses have the same shape, regardless of energy. The shapes of pulses from a nonlinear detector can and do depend on the pulse energy

A Thin-Film Cryotron Suitable For Use as an Ultra-Low-Temperature Switch

October 6, 2016
Author(s)
Peter J. Lowell, John A. Mates, William B. Doriese, Gene C. Hilton, Kelsey M. Morgan, Daniel S. Swetz, Joel N. Ullom, Daniel R. Schmidt
Low-temperature superconducting circuits have become important in modern science. However, there are presently no high-current-capacity switches with low power dissipation for sub-Kelvin operation. One candidate for a sub-Kelvin switch is the cryotron, a

First application of superconducting transition-edge-sensor microcalorimeters to hadronic-atom x-ray spectroscopy

September 30, 2016
Author(s)
Douglas Bennett, W.Bertrand (Randy) Doriese, Joseph Fowler, Johnathon Gard, James P. Hays-Wehle, Gene C. Hilton, Carl D. Reintsema, Daniel Swetz, Joel Ullom
High-resolution pionic-atom x-ray spectroscopy was performed with an x-ray spectrometer based on a 240-pixel array of superconducting transition-edge-sensor (TES)microcalorimeters at the πM1 beam line of the Paul Scherrer Institute. The pionic-carbon 4 → 3

Ultrafast time-resolved hard x-ray emission spectroscopy on a table top

September 27, 2016
Author(s)
Luis Miaja Avila, Galen C. O'Neil, Young Il Joe, Bradley K. Alpert, Niels Damrauer, William B. Doriese, Steven Fatur, Joseph W. Fowler, Gene C. Hilton, Ralph Jimenez, Carl D. Reintsema, Daniel R. Schmidt, Kevin L. Silverman, Daniel S. Swetz, Hideyuki Tatsuno, Joel N. Ullom
Chemical reactions driven by light are fundamental to biology and a source of inspiration for engineering materials to perform tasks such as solar energy harvesting and data storage. Observing and understanding photodynamics requires experimental tools

Code-division-multiplexed readout of large arrays of TES microcalorimeters

September 15, 2016
Author(s)
Kelsey M. Morgan, Bradley K. Alpert, Douglas A. Bennett, William B. Doriese, Joseph W. Fowler, Johnathon D. Gard, Gene C. Hilton, Kent D. Irwin, Young Il Joe, Galen C. O'Neil, Carl D. Reintsema, Edward V. Denison, Daniel R. Schmidt, Joel N. Ullom, Daniel S. Swetz
Code-division multiplexing (CDM) offers a path to reading out large arrays of transition edge sensor (TES) X-ray micro-calorimeters with excellent energy and timing resolution. We demonstrate the readout of X-ray TESs with a 32-channel flux-summed code

Design of 280 GHz feedhorn-coupled TES arrays for the balloon-borne polarimeter SPIDER

July 7, 2016
Author(s)
Johannes Hubmayr, Jason E. Austermann, James A. Beall, Daniel T. Becker, Shannon M. Duff, Arpi L. Grigorian, Gene C. Hilton, Joel N. Ullom, Michael R. Vissers
We describe 280 GHz bolometric detector arrays that instrument the balloon-borne polarimeter spider. A primary science goal of spider is to measure large-scale B-mode polarization of the cosmic microwave back-ground (cmb) in search of the cosmic-inflation

Absolute Energy Calibration of X-ray TESs with 0.04 eV Uncertainty at 6.4 keV in a Hadron-Beam Environment

January 19, 2016
Author(s)
Hideyuki Tatsuno, William B. Doriese, Douglas A. Bennett, Catalina Curceanu, Joseph W. Fowler, Johnathon D. Gard, Fredrick P. Gustafsson, Tadashi Hashimoto, Ryugo S. Hayano, James P. Hays-Wehle, Gene C. Hilton, Mihail Iliescu, Shigeru Ishimoto, Kenta Itahashi, Masashiko Iwasaki, Keisuke Kuwabara, Yue Ma, Johann Marton, Hirofumi Noda, Galen C. O'Neil, Shinji Okada, Haruhiko Outa, Carl D. Reintsema, Masaharu Sato, Daniel R. Schmidt, Hexi Shi, Ken Suzuki, Takatoshi Suzuki, Jens Uhlig, Joel N. Ullom, Eberhard Widmann, Shinya Yamada, Johann Zmeskal, Daniel S. Swetz
A performance evaluation of superconducting transition-edge sensors (TESs) in the environment of a pion beam line at a particle accelerator is presented. Averaged across the 209 functioning sensors in the array, the achieved energy resolution is 5.2 eV

Algorithms for Identification of Nearly-Coincident Events in Calorimetric Sensors

December 29, 2015
Author(s)
Bradley K. Alpert, Elena Ferri, Douglas A. Bennett, Marco Faverzani, Joseph W. Fowler, Andrea Giachero, James P. Hays-Wehle, Angelo Nucciotti, Daniel S. Swetz, Joel N. Ullom
For experiments with high arrival rates, reliable identification of nearly-coincident events can be crucial. For calorimetric measurements to directly measure the neutrino mass such as HOLMES, unidentified pulse pile-ups are expected to comprise a leading

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
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