High dynamic range active pixel sensor arrays for digital x-ray imaging using a-Si:H
- Electrical and Computer Engineering Department, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
Hydrogenated amorphous silicon (a-Si:H) active matrix flat panel imagers have gained considerable significance in large area digital imaging applications, in view of their large area readout capability. Current interests lie in a multifaceted a-Si:H array which is compatible with multiple x-ray imaging modalities. This concept entails a single detector system with sufficient dynamic range and variable signal gain. This article reports on an active pixel sensor (APS) array with high dynamic range and programable gain for multimodality x-ray imaging. Initial results have demonstrated sensitivity from subpicoampere to nanoampere photocurrent, which proves amenable for both low-dosage dynamic imaging and high input static imaging. In addition, the programable system signal gain alleviates problems such as output saturation and ensures signal readout linearity to further improve the exploitable dynamic range. Together with external amplification, this APS circuit delivers the performance needed in terms of signal gain, dynamic range, and readout rate entailed by fluoroscopic and radiographic imaging applications.
- OSTI ID:
- 20777202
- Journal Information:
- Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 24, Issue 3; Other Information: DOI: 10.1116/1.2192526; (c) 2006 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
- Country of Publication:
- United States
- Language:
- English
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