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Title: Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure

Abstract

Purpose: The authors are investigating the feasibility of a new type of solid-state x-ray imaging sensor with programmable avalanche gain: scintillator high-gain avalanche rushing photoconductor active matrix flat panel imager (SHARP-AMFPI). The purpose of the present work is to investigate the inherent x-ray detection properties of SHARP and demonstrate its wide dynamic range through programmable gain. Methods: A distributed resistive layer (DRL) was developed to maintain stable avalanche gain operation in a solid-state HARP. The signal and noise properties of the HARP-DRL for optical photon detection were investigated as a function of avalanche gain both theoretically and experimentally, and the results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid-state SHARP x-ray image sensor was formed by direct optical coupling of the HARP-DRL with a structured cesium iodide (CsI) scintillator. The x-ray sensitivity of this sensor was measured as a function of avalanche gain and the results were compared with the sensitivity of HARP-DRL measured optically. The dynamic range of HARP-DRL with variable avalanche gain was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications. Results: The signal from HARP-DRL asmore » a function of electric field showed stable avalanche gain, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x-ray detection, the additional noise associated with avalanche gain in HARP-DRL is negligible. The x-ray sensitivity measurements using the SHARP sensor produced identical avalanche gain dependence on electric field as the optical measurements with HARP-DRL. Adjusting the avalanche multiplication gain in HARP-DRL enabled a very wide dynamic range which encompassed all clinically relevant medical x-ray exposures. Conclusions: This work demonstrates that the HARP-DRL sensor enables the practical implementation of a SHARP solid-state x-ray sensor capable of quantum noise limited operation throughout the entire range of clinically relevant x-ray exposures. This is an important step toward the realization of a SHARP-AMFPI x-ray flat-panel imager.« less

Authors:
; ; ; ;  [1];  [2];  [3];  [4]
  1. Department of Radiation Oncology, Sunnybrook Health Sciences Center, Toronto, Ontario M4N 3M5 (Canada)
  2. (United States)
  3. (Japan)
  4. (Canada)
Publication Date:
OSTI Identifier:
22099095
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 39; Journal Issue: 11; Other Information: (c) 2012 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 60 APPLIED LIFE SCIENCES; CESIUM IODIDES; ELECTRON BEAMS; FLUOROSCOPY; GAIN; NOISE; PERFORMANCE; PHOTONS; SENSITIVITY; SENSORS; TOWNSEND DISCHARGE; X RADIATION; X-RAY DETECTION

Citation Formats

Wronski, M., Zhao, W., Tanioka, K., DeCrescenzo, G., Rowlands, J. A., Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794-8460, Tokyo Denki University, Tokyo, 120-8551, and Thunder Bay Regional Research Institute, Thunder Bay, Ontario P7A 7T1. Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure. United States: N. p., 2012. Web. doi:10.1118/1.4760989.
Wronski, M., Zhao, W., Tanioka, K., DeCrescenzo, G., Rowlands, J. A., Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794-8460, Tokyo Denki University, Tokyo, 120-8551, & Thunder Bay Regional Research Institute, Thunder Bay, Ontario P7A 7T1. Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure. United States. doi:10.1118/1.4760989.
Wronski, M., Zhao, W., Tanioka, K., DeCrescenzo, G., Rowlands, J. A., Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794-8460, Tokyo Denki University, Tokyo, 120-8551, and Thunder Bay Regional Research Institute, Thunder Bay, Ontario P7A 7T1. Thu . "Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure". United States. doi:10.1118/1.4760989.
@article{osti_22099095,
title = {Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure},
author = {Wronski, M. and Zhao, W. and Tanioka, K. and DeCrescenzo, G. and Rowlands, J. A. and Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794-8460 and Tokyo Denki University, Tokyo, 120-8551 and Thunder Bay Regional Research Institute, Thunder Bay, Ontario P7A 7T1},
abstractNote = {Purpose: The authors are investigating the feasibility of a new type of solid-state x-ray imaging sensor with programmable avalanche gain: scintillator high-gain avalanche rushing photoconductor active matrix flat panel imager (SHARP-AMFPI). The purpose of the present work is to investigate the inherent x-ray detection properties of SHARP and demonstrate its wide dynamic range through programmable gain. Methods: A distributed resistive layer (DRL) was developed to maintain stable avalanche gain operation in a solid-state HARP. The signal and noise properties of the HARP-DRL for optical photon detection were investigated as a function of avalanche gain both theoretically and experimentally, and the results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid-state SHARP x-ray image sensor was formed by direct optical coupling of the HARP-DRL with a structured cesium iodide (CsI) scintillator. The x-ray sensitivity of this sensor was measured as a function of avalanche gain and the results were compared with the sensitivity of HARP-DRL measured optically. The dynamic range of HARP-DRL with variable avalanche gain was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications. Results: The signal from HARP-DRL as a function of electric field showed stable avalanche gain, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x-ray detection, the additional noise associated with avalanche gain in HARP-DRL is negligible. The x-ray sensitivity measurements using the SHARP sensor produced identical avalanche gain dependence on electric field as the optical measurements with HARP-DRL. Adjusting the avalanche multiplication gain in HARP-DRL enabled a very wide dynamic range which encompassed all clinically relevant medical x-ray exposures. Conclusions: This work demonstrates that the HARP-DRL sensor enables the practical implementation of a SHARP solid-state x-ray sensor capable of quantum noise limited operation throughout the entire range of clinically relevant x-ray exposures. This is an important step toward the realization of a SHARP-AMFPI x-ray flat-panel imager.},
doi = {10.1118/1.4760989},
journal = {Medical Physics},
issn = {0094-2405},
number = 11,
volume = 39,
place = {United States},
year = {2012},
month = {11}
}