111 research outputs found
Sentenced to be hanged and other stories
No full textThis book contains four fictional tales by Newfoundland writer P. J. Wakeham; a "detective story, a tale of espionage, and two sea stories" (foreword). All set in Newfoundland, the stories will entertain readers by combining adventure, romance, and history.Sentenced to be hanged -- Undercover agent -- The girl in the pirates cabin -- Easten's Caribbean voyageSigned by author on p. [2] of cover. -- Includes advertisements
Mutiny at midnight : a thrilling adventure story
No full textThe first of many books both written and published by Newfoundland author Wakeham, this fictional tale tells of the adventures of the captain and crew of the good ship "Trigger" as she makes her way from St. John's to catch seals in the Antarctic in 1729.Author's signature on title page
Electron-Beam Deposition of Superconducting Molybdenum Thin Films for the Development of Mo/Au TES X-ray Microcalorimeter
No full textFred Michael Finkbeiner, Joseph S. Adams, Simon R. Bandler, Gabriele L. Betancourt-Martinez, Ari David Brown, Meng-Ping Chang, James A. Chervenak, Meng P. Chiao, Aaron M. Datesman, Megan E. Eckart, Richard L. Kelley, Caroline A. Kilbourne, Antoine Miniussi, Samuel J. Moseley, Frederick Scott Porter, John E. Sadleir, Kazuhiro Sakai, Stephen James Smith, Nicholas A. Wakeham, Edward J. Wassell, and Wonisk YoonWe are exploring the properties of electron-beam
evaporated molybdenum thin films on silicon nitride coated silicon wafers at substrate temperatures between room temperature
and 650 °C. The temperature dependence of film stress, transition temperature, and electrical properties are presented. X-ray
diffraction measurements are performed to gain information on
molybdenum crystallite size and growth. Results show the dominant influence of the crystallite size on the intrinsic properties of
our films. Wafer-scale uniformity, wafer yield, and optimal thermal
bias regime for TES fabrication are discussed.https://ieeexplore.ieee.org/abstract/document/7762784
A test platform for the detection and readout chain for the Athena X-IFU
No full textGabriele Betancourt-Martinez, François Pajot, Sophie Beaumont, Gilles Roudil, Joseph Adams, Hiroki Akamatsu, Simon Bandler, Bernard Bertrand, Marcel Bruijn, Florent Castellani, Edoardo Cucchetti, William Doriese, Michel Dupieux, Hervé Geoffray, Luciano Gottardi, Brian Jackson, Jan van der Kuur, Mikko Kiviranta, Antoine Miniussi, Phillipe Peille, Kevin Ravensberg, Laurent Ravera, Carl Reintsema, Kazuhiro Sakai, Stephen Smith, Nicholas Wakeham, Henk van Weers, Doreen Wernicke, Michael WitthoeftWe present a test platform for the Athena X-IFU detection chain, which will serve as the first demonstration of the representative end-to-end detection and readout chain for the X-IFU, using prototypes of the future flight
electronics and currently available subsystems. This test bench, housed in a commercial two-stage ADR cryostat,
includes a focal plane array placed at the 50 mK cold stage of the ADR with a kilopixel array of transition-edge sensor microcalorimeter spectrometers and associated cold readout electronics. Prototype room temperature electronics
for the X-IFU provide the readout, and will evolve over time to become more representative of the X-IFU mission
baseline. The test bench yields critical feedback on subsystem designs and interfaces, in particular the warm readout
electronics, and will provide an in-house detection system for continued testing and development of the warm readout
electronics and for the validation of X-ray calibration sources. In this paper, we describe the test bench subsystems
and design, characterization of the cryostat, and current status of the project.https://arxiv.org/abs/2107.0341
Study of Dissipative Losses in AC-Biased Mo/Au Bilayer Transition-Edge Sensors
No full textKazuhiro Sakai, · J. S. Adams, · S. R. Bandler · J. A. Chervenak · A. M. Datesman, · M. E. Eckart · F. M. Finkbeiner, · R. L. Kelley · C. A. Kilbourne · A. R. Miniussi, · F. S. Porter · J. S. Sadleir ·Stephen J. Smith, · Nicholas Wakeham, · E. J. Wassell, · W. Yoon, · H. Akamatsu · M. P. Bruijn · L. Gottardi · B. D. Jackson · J. van der Kuur · B. J. van Leeuwen · A. J. van der Linden · H. J. van Weers · M. KivirantaWe are developing kilo-pixel arrays of transition-edge sensors (TESs) for the X-ray
Integral Field Unit on ESA’s Athena observatory. Previous measurements of AC biased Mo/Au TESs have highlighted a frequency-dependent loss mechanism that
results in broader transitions and worse spectral performance compared to the same
devices measured under DC bias. In order to better understand the nature of this loss,
we are now studying TES pixels in different geometric configurations. We present
measurements on devices of different sizes and with different metal features used for
noise mitigation and X-ray absorption. Our results show how the loss mechanism is
strongly dependent upon the amount of metal in close proximity to the sensor and can
be attributed to induced eddy current coupling to these features. We present a finite
element model that successfully reproduces the magnitude and geometry dependence
of the losses. Using this model, we present mitigation strategies that should reduce
the losses to an acceptable level.https://link.springer.com/article/10.1007%2Fs10909-018-2002-
Performance of a Broad-Band, High-Resolution, Transition-Edge Sensor Spectrometer for X-ray Astrophysics
No full textStephen J. Smith , Joseph S. Adams, Simon R. Bandler, Sophie Beaumont , James A. Chervenak,
Edward V. Denison, William B. Doriese , Malcolm Durkin , Fred M. Finkbeiner , Joseph W. Fowler ,
Gene C. Hilton, Ruslan Hummatov , Kent D. Irwin, Richard L. Kelley, Caroline A. Kilbourne ,
Maurice A. Leutenegger, Antoine Miniussi , Frederick S. Porter, Carl D. Reintsema , John E. Sadleir,
Kazuhiro Sakai , Daniel S. Swetz, Joel N. Ullom, Leila R. Vale, Nicholas Wakeham, Edward J. Wassell ,
and Michael C. WitthoeftFuture X-ray astrophysics experiments require multiplexed readout of high fill-factor, kilo-pixel arrays of transition-edge sensors (TESs), with very high spectral resolution over a
broad range of energies. In this paper we report on a prototype
kilo-pixel array of Mo/Au TESs readout with 8-column by 32-row
time-division multiplexing (TDM). This system is being used to
demonstrate the critical detector and readout technology for ESA’s
Athena X-IFU, and when complete will be used in laboratory astrophysics experiments. Our array and TDM readout have demonstrated a combined full-width-at-half-maximum energy resolution,
including > 200 pixels, of: 1.95 eV for Ti-Kα (4.5 keV), 1.97 eV for
Mn-Kα (5.9 keV), 2.16 eV for Co-Kα (6.9 keV), 2.33 eV for Cu-Kα
(8 keV), 3.26 eV for Br-Kα (11.9 keV). The 1 sigma statistical errors
are ≤0.01 eV for all spectra. These results meet the broad-band
resolution requirements for X-IFU with margin.https://ieeexplore.ieee.org/abstract/document/936230
Reduced-Scale Transition-Edge Sensor Detectors for Solar and X-Ray Astrophysics
No full textAaron M. Datesman, Joseph S. Adams, Simon R. Bandler, Gabriele L. Betancourt-Martinez, Meng-Ping Chang, James A. Chervenak, Megan E. Eckart, Audrey E. Ewin, Fred M. Finkbeiner, Jong Yoon Ha, Richard L. Kelley, Caroline A. Kilbourne, Antoine Miniussi, Frederick S. Porter, John E. Sadleir, Kazuhiro Sakai, Stephen J. Smith, Nicholas A. Wakeham, Elissa H. Williams, Edward J. Wassell, and Wonsik YoonWe have developed large-format, close-packed X-ray
microcalorimeter arrays fabricated on solid substrates, designed
to achieve high energy resolution with count rates up to a few
hundred counts per second per pixel for X-ray photon energies up
to 8 keV. Our most recent arrays feature 31-micron absorbers on
a 35-micron pitch, reducing the size of pixels by about a factor of
two. This change will enable an instrument with significantly higher
angular resolution. In order to wire out large format arrays with
an increased density of smaller pixels, we have reduced the lateral
size of both the microstrip wiring and the Mo/Au transition-edge
sensors (TES). We report on the key physical properties of these
small TESs and the fine Nb leads attached, including the critical
currents and weak-link properties associated with the longitudinal
proximity effect.https://ieeexplore.ieee.org/abstract/document/7809109
Southern continuation of the Wakeham Group and Robe-Noire mafic suite (eastern Grenville Province) from hydrocarbon-targeted seismic reflection data on Anticosti Island, Quebec, Canada.
No full textHydrocarbon-targeted seismic reflection profiles acquired on eastern Anticosti Island (Quebec) image sub-parallel reflections with significant continuity below the Paleozoic St. Lawrence Platform. These intra-basement reflections define a seismic unit with a relatively simple geometry characterized by broad open folds, an array of sub-parallel markers and ENE-dipping faults. The reflective seismic unit likely corresponds to the southern extension of the Mesoproterozoic Wakeham Group and Robe-Noire mafic sills that are exposed on the nearby north shore of the Gulf of St. Lawrence, in the eastern Grenville Province of Quebec.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Energy Calibration of High-Resolution X-Ray TES Microcalorimeters With 3 eV Optical Photons
No full textF. T. Jaeckel , C. V. Ambarish, N. Christensen, R. Gruenke, L. Hu, D. McCammon, M. McPheron, M. Meyer, K. L. Nelms, A. Roy, D. Wulf, S. Zhang, Y. Zhou, J. S. Adams, S. R. Bandler, J. A. Chervenak, A. M. Datesman , M. E. Eckart, A. J. Ewin, F. M. Finkbeiner , R. Kelley, C. A. Kilbourne, Antoine Miniussi, F. S. Porter, J. E. Sadleir, Kazuhiro Sakai, Stephen J. Smith, Nicholas Wakeham, E. Wassell , W. Yoon , K. M. Morgan, D. R. Schmidt, D. S. Swetz, and J. N. UllomWith the improving energy resolution of transition-edge sensor (TES) based microcalorimeters, performance verification and calibration of these detectors have become increasingly
challenging, especially in the energy range below 1 keV where fluorescent atomic X-ray lines have linewidths that are wider than the
detector energy resolution and require impractically high statistics
to determine the gain and deconvolve the instrumental profile. Better behaved calibration sources such as grating monochromators
are too cumbersome for space missions and are difficult to use in
the lab. As an alternative, we are exploring the use of pulses of 3 eV
optical photons delivered by an optical fiber to generate combs of
known energies with known arrival times. Here, we discuss initial
results of this technique obtained with 2 and 0.7 eV resolution X-ray microcalorimeters. With the 2 eV detector, we have achieved
photon number resolution for pulses with mean photon number up
to 133 (corresponding to 0.4 keV).The authors would like to thank Jim Lawler, Mark Saffman,
Deniz Yavuz, Jim Reardon, and Brett Unks from the Department
of Physics, UW Madison, for their assistance with some aspects
of the optical setup.https://ieeexplore.ieee.org/abstract/document/8643436
Demonstration of Athena X-IFU Compatible 40-Row Time-Division-Multiplexed Readout
No full textMalcolm Durkin , Joseph S. Adams, Simon R. Bandler, James A. Chervenak, Saptarshi Chaudhuri, Carl S. Dawson, Edward V. Denison, William B. Doriese , Shannon M. Duff, Fred M. Finkbeiner , Connor T. FitzGerald, Joseph W. Fowler, Johnathon D. Gard, Gene C. Hilton, Kent D. Irwin, Young Il Joe, Richard L. Kelley, Caroline A. Kilbourne , Antoine Miniussi, Kelsey M. Morgan , Galen C. O’Neil, Christine G. Pappas, Frederick S. Porter, Carl D. Reintsema, David A. Rudman, Kazuhiro Sakai, Stephen J. Smith, Robert W. Stevens, Daniel S. Swetz, Paul Szypryt, Joel N. Ullom, Leila R. Vale, Nicholas Wakeham , Joel C. Weber, and Betty A. YoungTime-division multiplexing (TDM) is the backup
readout technology for the X-ray Integral Field Unit (X-IFU),
a 3168-pixel X-ray transition-edge sensor (TES) array that will
provide imaging spectroscopy for european space agency’s Athena
satellite mission. X-IFU design studies are considering readout
with a multiplexing factor of up to 40. We present data showing
40-row TDM readout (32 TES rows + 8 repeats of the last row) of
TESs that are of the same type as those being planned for X-IFU,
using measurement and analysis parameters within the ranges
specified for X-IFU. Single-column TDM measurements have best-fit energy resolution of (1.91 ± 0.01) eV for the Al Kα complex (1.5 keV), (2.10 ± 0.02) eV for Ti Kα (4.5 keV), (2.23 ± 0.02) eV for
Mn Kα (5.9 keV), (2.40 ± 0.02) eV for Co Kα (6.9 keV), and (3.44
± 0.04) eV for Br Kα (11.9 keV). Three-column measurements have best-fit resolution of (2.03 ± 0.01) eV for Ti Kα and (2.40
± 0.01) eV for Co Kα. The degradation due to the multiplexed
readout ranges from 0.1 eV at the lower end of the energy range
to 0.5 eV at the higher end. The demonstrated performance meets
X-IFU’s energy-resolution and energy-range requirements. True
40-row TDM readout, without repeated rows, of kilopixel scale
arrays of X-IFU-like TESs is now under development.https://ieeexplore.ieee.org/document/867147
- …
