Ms. Carolyn Thayer Profile

Carolyn Thayer

Graduate Student at Univ of Michigan

SPIE Involvement:

Author

Publications (8)

SPIE Journal Paper | 2 February 2022 Open Access

Measurement and simulation of charge diffusion in a small-pixel charge-coupled device

Beverly LaMarr, Gregory Prigozhin, Eric Miller, Carolyn Thayer, Marshall Bautz, Richard Foster, Catherine Grant, Andrew Malonis, Barry Burke, Michael Cooper, Kevan Donlon, Christopher Leitz

JATIS, Vol. 8, Issue 01, 016004, (February 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.1.016004

KEYWORDS: Sensors, X-rays, Diffusion, Charge-coupled devices, Spectral resolution, Electrons, X-ray detectors, X-ray imaging, Silicon, Photons

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Future high-resolution imaging x-ray observatories may require detectors with both fine spatial resolution and high quantum efficiency at relatively high x-ray energies (E ≥ 5 keV). A silicon imaging detector meeting these requirements will have a ratio of detector thickness to pixel size of six or more, roughly twice that of legacy imaging sensors. The larger aspect ratio of such a sensor’s detection volume implies greater diffusion of x-ray-produced charge packets. We investigate consequences of this fact for sensor performance, reporting charge diffusion measurements in a fully depleted back-illuminated CCD with a thickness of 50 μm and pixel size of 8 μm. We are able to measure the size distributions of charge packets produced by 5.9 and 1.25 keV x-rays in this device. We find that individual charge packets exhibit a Gaussian spatial distribution and determine the frequency distribution of event widths for a range of detector bias (and thus internal electric field strength) levels. At the largest bias, we find a standard deviation for the largest charge packets (produced by x-ray interactions closest to the entrance surface of the device) of 3.9 μm. We show that the shape of the event width distribution provides a clear indicator of full depletion and use a previously developed technique to infer the relationship between event width and interaction depth. We compare measured width distributions to simulations. Although we can obtain good agreement for a given detector bias, with our current simulation, we are unable to fit the data for the full range of bias levels with a single set of simulation parameters. We compare traditional, “sum-above-threshold” algorithms for individual event amplitude determination to Gaussian fitting of individual events and find that better spectroscopic performance is obtained with the former for 5.9 keV events, whereas the two methods provide comparable results at 1.25 keV. The reasons for this difference are discussed. We point out the importance of read-noise driven charge detection thresholds in degrading spectral resolution, and note that the derived read noise requirements for mission concepts such as AXIS and Lynx are probably too lax to assure that spectral resolution requirements can be met. While the measurements reported here were made with a CCD, we note that they have implications for the performance of high aspect-ratio silicon active pixel sensors as well.

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SPIE Journal Paper | 22 December 2021

Performance of a directly deposited optical blocking filter on x-ray CCDs: case study from the REgolith X-ray Imaging Spectrometer (REXIS) experiment

Carolyn Thayer, Rebecca Masterson, Branden Allen, Kevin Ryu, Marshall Bautz, Solan Megerssa, Mark Chodas, David Guevel, Daniel Hoak, Jaesub Hong, Madeline Lambert, Jonathan Grindlay, Richard Binzel

JATIS, Vol. 7, Issue 04, 046001, (December 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.4.046001

KEYWORDS: Charge-coupled devices, X-rays, X-ray optics, Sensors, Asteroids, Optical filters, X-ray imaging, High power microwaves, Spectroscopy, Environmental sensing

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Proceedings Article | 13 December 2020 Poster + Presentation + Paper

Progress toward fast, low-noise, low-power CCDs for Lynx and other high-energy astrophysics missions

M. Bautz, B. Burke, M. Cooper, D. Craig, K. Donlon, R. Foster, C. E. Grant, B. LaMarr, C. Leitz, A. Malonis, E. Miller, G. Prigozhin, C. Thayer, S. Allen, S. Herrmann, T. Chattopadhyay, R. G. Morris

Proceedings Volume 11444, 1144494 (2020) https://doi.org/10.1117/12.2561441

KEYWORDS: Charge-coupled devices, Signal processing, High energy astrophysics, Sensors, X-rays, Clocks, X-ray detectors, X-ray imaging, Image sensors, Sensor performance

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Proceedings Article | 13 December 2020 Poster + Presentation + Paper

Radiation testing of a small pixel, CMOS compatible CCD

Beverly LaMarr, Marshall Bautz, Richard Foster, Catherine Grant, Andrew Malonis, Eric Miller, Gregory Prigozhin, Carolyn Thayer

Proceedings Volume 11444, 1144495 (2020) https://doi.org/10.1117/12.2561625

KEYWORDS: Charge-coupled devices, X-ray imaging, Sensors, Environmental sensing, Space operations, Detector development

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SPIE Journal Paper | 20 May 2019 Open Access

Toward fast, low-noise charge-coupled devices for Lynx

Marshall Bautz, Barry Burke, Michael Cooper, David Craig, Richard Foster, Catherine Grant, Beverly LaMarr, Christopher Leitz, Andrew Malonis, Eric Miller, Gregory Prigozhin, Daniel Schuette, Vyshnavi Suntharalingam, Carolyn Thayer

JATIS, Vol. 5, Issue 02, 021015, (May 2019) https://doi.org/10.1117/12.10.1117/1.JATIS.5.2.021015

KEYWORDS: Sensors, Charge-coupled devices, X-rays, Clocks, Electrons, Amplifiers, Spectral resolution, Silicon, X-ray detectors, Tolerancing

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Lynx requires large-format x-ray imaging detectors with performance at least as good as the best current-generation devices but with much higher readout rates. We are investigating an advanced charge-coupled device (CCD) detector architecture under development at MIT Lincoln Laboratory for use in the Lynx high-definition x-ray imager and x-ray grating spectrometer instruments. This architecture features a CMOS-compatible detector integrated with parallel CMOS signal processing chains. Fast, low-noise amplifiers and highly parallel signal processing provide the high frame rates required. CMOS-compatibility of the CCD enables low-power charge transfer and signal processing. We report on the performance of CMOS-compatible test CCDs read at pixel rates up to 5.0 Mpix s − 1 (50 times faster than Chandra ACIS CCDs), with transfer clock swings as low as 1.0-V peak-to-peak (power/gate-area comparable to ACIS CCDs at 100 times the parallel transfer rate). We measure read noise of 4.6 electrons RMS at 2.5 MHz and x-ray spectral resolution better than 150-eV full-width at half maximum at 5.9 keV for single-pixel events. We report charge transfer efficiency measurements and demonstrate that buried channel trough implants as narrow as 0.8 μm are effective in improving charge transfer performance. We find that the charge transfer efficiency of these devices drops significantly as detector temperature is reduced from ∼ − 30 ° C to −60 ° C. We point out the potential of previously demonstrated curved-detector fabrication technology for simplifying the design of the Lynx high-definition imager. We discuss the expected detector radiation tolerance at these relatively high transfer rates. Finally, we note that the high pixel “aspect ratio” (depletion depth: pixel size ≈9 ∶ 1) of our test devices is similar to that expected for Lynx detectors and discuss implications of this geometry for x-ray performance and noise requirements.

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Proceedings Article | 5 August 2016 Paper

Quantum efficiency measurement of the Transiting Exoplanet Survey Satellite (TESS) CCD detectors

A. Krishnamurthy, J. Villasenor, C. Thayer, S. Kissel, G. Ricker, S. Seager, R. Lyle, A. Deline, E. Morgan, T. Sauerwein, R. Vanderspek

Proceedings Volume 9904, 99042W (2016) https://doi.org/10.1117/12.2232244

KEYWORDS: Charge-coupled devices, Quantum efficiency, Calibration, Sensors, CCD image sensors, Photodiodes, Light sources, Integrating spheres, Bandpass filters, Optical filters

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Proceedings Article | 29 July 2016 Paper

Testing and characterization of the TESS CCDs

C. Thayer, J. Villasenor, S. Kissel, B. LaMarr, E. Morgan, G. Prigozhin, I. Prigozhin, G. Ricker, T. Sauerwein, V. Suntharalingam, R. Vanderspek, D. Woods

Proceedings Volume 9904, 99042X (2016) https://doi.org/10.1117/12.2232886

KEYWORDS: Charge-coupled devices, Sensors, Cameras, Stars, Electronics, X-rays, Light emitting diodes, Imaging arrays, Floods, Temperature metrology

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Proceedings Article | 29 July 2016 Paper

The TESS camera: modeling and measurements with deep depletion devices

Deborah Woods, Roland Vanderspek, Robert MacDonald, Edward Morgan, Joel Villasenor, Carolyn Thayer, Barry Burke, Christian Chesbrough, Michael Chrisp, Kristin Clark, Gabor Furesz, Alexandria Gonzales, Tam Nguyen, Gregory Prigozhin, Brian Primeau, George Ricker, Timothy Sauerwein, Vyshnavi Suntharalingam

Proceedings Volume 9904, 99042C (2016) https://doi.org/10.1117/12.2231296

KEYWORDS: Instrument modeling, Zemax, Sensors, Cameras, Monte Carlo methods, Silicon, Zemax, Charge-coupled devices, Photons, Diffusion, Point spread functions

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Showing 5 of 8 publications

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