Dr. Conner Brown Profile

Dr. Conner Brown

at Radiation Monitoring Devices

SPIE Involvement:

Author

Publications (3)

Proceedings Article | 4 October 2022 Presentation + Paper

Thermal neutron detection with lithium-based semiconductors

Alireza Kargar, Huicong Hong, Joshua Tower, Paul Guggenheim, Eric Qian, Conner Brown, Mathew Breen, James Christian, Kanai Shah, Eric Lukosi, Robert Golduber, Jake Gallagher, Amine Benkechkache, Mercouri Kanatzidis, Michael Squillante

Proceedings Volume 12241, 1224108 (2022) https://doi.org/10.1117/12.2632318

KEYWORDS: Sensors, Crystals, Lithium, Semiconductors, Transmittance, Gold, Gamma radiation, Selenium, Electrons, Semiconducting wafers

Read Abstract +

Proceedings Article | 3 October 2022 Presentation

Performance characterizations of position-sensitive virtual Frisch-grid TlBr detectors (Conference Presentation)

Aleksey Bolotnikov, Conner Brown, Gabriella Carini, James Christian, Leonard Cirignano, Connie-Rose Deane, Alfred Dellapenna, Grzegorz Deptuch, Jack Fried, Sven Herrmann, Hadong Kim, Giovanni Pinaroli, Alireza Kargar, Martin Koslowsky, Piotr Maj, Victor Manthena, Alexander Miller, Sandeep Miriala, Eric Raguzina, Kanai Shah, Michael Squillante, Martin Smith, Andrew Valente, Evan Weststrate

Proceedings Volume PC12241, PC122410D (2022) https://doi.org/10.1117/12.2635899

KEYWORDS: Sensors, Crystals, Semiconductors, Semiconductor materials, Ions, Gamma radiation, Electric field sensors

Read Abstract +

Proceedings Article | 16 March 2020 Presentation + Paper

Pixelated columnar CsI:Tl scintillator for high resolution radiography and cone-beam CT

Stuart Miller, Bipin Singh, Matthew S. Marshall, Conner Brown, Niral Sheth, Gengxin Shi, Jeffrey Siewerdsen, Wojciech Zbijewski, Vivek Nagarkar

Proceedings Volume 11312, 1131212 (2020) https://doi.org/10.1117/12.2550196

KEYWORDS: Scintillators, Bone, Spatial resolution, Sensors, Image resolution, Atomic layer deposition, CMOS sensors, Radiography

Read Abstract +

Microcolumnar CsI:Tl scintillator screens have been the gold standard in X-ray imaging for many years due to their high density, high atomic number, and scintillation efficiency. The structured screens provide an improvement in performance by channeling the light to the detector, improving detection efficiency and spatial resolution. We have taken this concept a step further by laser-machining the CsI:Tl scintillator to provide pixels that match the detector pixels. This allows for still thicker CsI:Tl layers up to 700 μm pixelated with pitch of 100 μm to match CMOS flat panel pixels, thus improving X-ray absorption and resolution. We are investigating the applications of CMOS detectors with pixelated scintillators for imaging of bone microarchitecture on diagnostic Cone Beam CT (CBCT) systems to provide improved quantitative metrics for diagnosis of osteoporosis and osteoarthritis.

The scintillator design includes reflective coatings applied to the laser-cut grooves to improve optical isolation between pixels. Such coatings are created by atomic layer deposition (ALD), a unique approach, which permits formation of reflectors over inter-pixel grooves with aspect ratios as high as 140:1. Here we present initial results quantifying performance gains in CMOS detector resolution and their impact on the quality of bone microstructure segmentation. We demonstrate 77% gain in spatial resolution at 2 lp/mm and extension of the limiting resolution from 3 lp/mm to 4.5 lp/mm for the CMOS detector with a pixelated screen compared to a commercial sensor. In a bench-top CBCT study emulating diagnostic systems for orthopedic applications (extremity CBCT), we achieved >0.75 correlations in metrics of trabecular microarchitecture between pixelated CsI:Tl based CBCT and gold-standard micro-CT. The pixelated scintillator is expected to have significant impact for many other applications including mammography and digital radiography, where resolution and dose efficiency (DQE) of the detector are of critical importance.

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years