Mr. Jonathan T. Ward Profile

Jonathan T. Ward

at Univ of Pennsylvania

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Author

Publications (7)

Proceedings Article | 24 July 2018 Presentation + Paper

Performance of the advanced ACTPol low frequency array

Yaqiong Li, Jason Austermann, James Beall, Sarah Marie Bruno, Steve Choi, Nicholas Cothard, Kevin Crowley, Shannon Duff, Patricio Gallardo, Shawn Henderson, Shuay-Pwu Patty Ho, Johannes Hubmayr, Brian Koopman, Jeff McMahon, Michael Niemack, Maria Salatino, Sara Simon, Suzanne Staggs, Jason Stevens, Joel Ullom, Jonathan Ward, Edward Wollack

Proceedings Volume 10708, 107080A (2018) https://doi.org/10.1117/12.2313942

KEYWORDS: Sensors, Semiconducting wafers, Bolometers, Silicon, Detector arrays, Polarization, Superconductors, Optical testing

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Proceedings Article | 7 March 2017 Paper

Highly uniform 150 mm diameter multichroic polarimeter array deployed for CMB detection

Shuay-Pwu Patty Ho, Jason Austermann, James Beall, Steve Choi, Nicholas Cothard, Kevin Crowley, Rahul Datta, Mark Devlin, Shannon Duff, Patricio Gallardo, Matthew Hasselfield, Shawn Henderson, Gene Hilton, Johannes Hubmayr, Brian Koopman, Yaqiong Li, Jeffrey McMahon, Michael Niemack, Maria Salatino, Sara Simon, Suzanne Staggs, Jonathan Ward, Joel Ullom, Eve Vavagiakis, Edward Wollack

Proceedings Volume 9914, 991418 (2017) https://doi.org/10.1117/12.2233113

KEYWORDS: Sensors, Telescopes, Receivers, Microwave radiation, Polarimetry, Bolometers, Polarization, Detector arrays, Anisotropy, Superconducting detectors

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Proceedings Article | 20 July 2016 Paper

Optical modeling and polarization calibration for CMB measurements with ACTPol and Advanced ACTPol

Brian Koopman, Jason Austermann, Hsiao-Mei Cho, Kevin Coughlin, Shannon Duff, Patricio Gallardo, Matthew Hasselfield, Shawn Henderson, Shuay-Pwu Patty Ho, Johannes Hubmayr, Kent Irwin, Dale Li, Jeff McMahon, Federico Nati, Michael Niemack, Laura Newburgh, Lyman Page, Maria Salatino, Alessandro Schillaci, Benjamin Schmitt, Sara Simon, Eve Vavagiakis, Jonathan Ward, Edward Wollack

Proceedings Volume 9914, 99142T (2016) https://doi.org/10.1117/12.2231912

KEYWORDS: Polarization, Calibration, Telescopes, Sensors, Signal detection, Sensors, Code v, Ray tracing, Receivers, Geometrical optics, Microwave radiation

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The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade to the Atacama Cosmology Telescope, located at an elevation of 5190 m on Cerro Toco in Chile. ACTPol uses transition edge sensor bolometers coupled to orthomode transducers to measure both the temperature and polarization of the Cosmic Microwave Background (CMB). Calibration of the detector angles is a critical step in producing polarization maps of the CMB. Polarization angle offsets in the detector calibration can cause leakage in polarization from E to B modes and induce a spurious signal in the EB and TB cross correlations, which eliminates our ability to measure potential cosmological sources of EB and TB signals, such as cosmic birefringence. We calibrate the ACTPol detector angles by ray tracing the designed detector angle through the entire optical chain to determine the projection of each detector angle on the sky. The distribution of calibrated detector polarization angles are consistent with a global offset angle from zero when compared to the EB-nulling offset angle, the angle required to null the EB cross-correlation power spectrum. We present the optical modeling process. The detector angles can be cross checked through observations of known polarized sources, whether this be a galactic source or a laboratory reference standard. To cross check the ACTPol detector angles, we use a thin film polarization grid placed in front of the receiver of the telescope, between the receiver and the secondary reflector. Making use of a rapidly rotating half-wave plate (HWP) mount we spin the polarizing grid at a constant speed, polarizing and rotating the incoming atmospheric signal. The resulting sinusoidal signal is used to determine the detector angles. The optical modeling calibration was shown to be consistent with a global offset angle of zero when compared to EB nulling in the first ACTPol results and will continue to be a part of our calibration implementation. The first array of detectors for Advanced ACTPol, the next generation upgrade to ACTPol, will be deployed in 2016. We plan to continue using both techniques and compare them to astrophysical source measurements for the Advanced ACTPol polarization calibration.

Proceedings Article | 20 July 2016 Paper

Assembly and integration process of the first high density detector array for the Atacama Cosmology Telescope

Yaqiong Li, Steve Choi, Shuay-Pwu Ho, Kevin Crowley, Maria Salatino, Sara Simon, Suzanne Staggs, Federico Nati, Jonathan Ward, Benjamin Schmitt, Shawn Henderson, Brian Koopman, Patricio Gallardo, Eve Vavagiakis, Michael Niemack, Jeff McMahon, Shannon Duff, Alessandro Schillaci, Johannes Hubmayr, Gene Hilton, James Beall, Edward Wollack

Proceedings Volume 9914, 991435 (2016) https://doi.org/10.1117/12.2233470

KEYWORDS: Sensors, Semiconducting wafers, Multiplexers, Detector arrays, Wafer bonding, Optical alignment, Copper, Silicon, Aluminum, Cements

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Proceedings Article | 19 July 2016 Paper

The design and characterization of wideband spline-profiled feedhorns for Advanced ACTPol

Sara Simon, Jason Austermann, James Beall, Steve Choi, Kevin Coughlin, Shannon Duff, Patricio Gallardo, Shawn Henderson, Felicity Hills, Shuay-Pwu Patty Ho, Johannes Hubmayr, Alec Josaitis, Brian Koopman, Jeff McMahon, Federico Nati, Laura Newburgh, Michael Niemack, Maria Salatino, Alessandro Schillaci, Benjamin Schmitt, Suzanne Staggs, Eve Vavagiakis, Jonathan Ward, Edward Wollack

Proceedings Volume 9914, 991416 (2016) https://doi.org/10.1117/12.2233603

KEYWORDS: Polarization, Sensors, Optical simulations, Telescopes, Waveguides, Semiconducting wafers, Deep reactive ion etching, Receivers, Physics, Electromagnetism

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Proceedings Article | 19 July 2016 Paper

Readout of two-kilopixel transition-edge sensor arrays for Advanced ACTPol

Shawn Henderson, Jason Stevens, Mandana Amiri, Jason Austermann, James Beall, Saptarshi Chaudhuri, Hsiao-Mei Cho, Steve Choi, Nicholas Cothard, Kevin Crowley, Shannon Duff, Colin Fitzgerald, Patricio Gallardo, Mark Halpern, Matthew Hasselfield, Gene Hilton, Shuay-Pwu Patty Ho, Johannes Hubmayr, Kent Irwin, Brian Koopman, Dale Li, Yaqiong Li, Jeff McMahon, Federico Nati, Michael Niemack, Carl Reintsema, Maria Salatino, Alessandro Schillaci, Benjamin Schmitt, Sara Simon, Suzanne Staggs, Eve Vavagiakis, Jonathan Ward

Proceedings Volume 9914, 99141G (2016) https://doi.org/10.1117/12.2233895

KEYWORDS: Multiplexing, Electronics, Sensors, Multiplexing, Electronics, Superconductors, Inductance, Polarization, Multiplexers, Interfaces, Tellurium, Servomechanisms

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Proceedings Article | 19 July 2016 Paper

Mechanical designs and development of TES bolometer detector arrays for the Advanced ACTPol experiment

Jonathan Ward, Jason Austermann, James Beall, Steve Choi, Kevin Crowley, Mark Devlin, Shannon Duff, Patricio Gallardo, Shawn Henderson, Shuay-Pwu Patty Ho, Gene Hilton, Johannes Hubmayr, Niloufar Khavari, Jeffrey Klein, Brian Koopman, Dale Li, Jeffrey McMahon, Grace Mumby, Federico Nati, Michael Niemack, Lyman Page, Maria Salatino, Alessandro Schillaci, Benjamin Schmitt, Sara Simon, Suzanne Staggs, Robert Thornton, Joel Ullom, Eve Vavagiakis, Edward Wollack

Proceedings Volume 9914, 991437 (2016) https://doi.org/10.1117/12.2233746

KEYWORDS: Detector arrays, Sensors, Semiconducting wafers, Mechanical engineering, Bolometers, Waveguides, Copper, Electronics, Receivers, Magnetism

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Showing 5 of 7 publications

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