Co-sponsored by: ECE Department, Concordia University

X-ray imagers couple light-sensing active-matrix arrays to an X-ray sensitive scintillator and typically have a pixel pitch of at least 50-μm. Achieving smaller pixel pitch, while desirable for better spatial resolution, is challenging because of the well- known tradeoff between the scintillator’s X-ray absorption properties and spatial resolution. As an alternative, direct-conversion imagers convert X-rays directly into electronic charge and overcome the scintillator thickness tradeoff by employing thick semiconductors with an applied bias that yields both high X-ray absorption and high spatial resolution. Using direct-conversion materials, dramatically smaller pixel sizes are achievable while maintaining dose efficiency, both of which are critical to advance in vivo imaging techniques in bioengineering (e.g. via X-ray micro-CT). In this talk, we discuss the integration of low-noise CMOS electronics with an amorphous selenium (a-Se) direct X-ray photoconductor to yield a 32 × 32 pixel array having a pixel size of 5.6 μm × 6.25 μm and strategies to achieve real-time imager operation. Under dark conditions, an input-referred electronic noise of È

Speaker(s): Karim S. Karim,

Agenda:

Location:
Room: EV003-309
Bldg: EV Building,
1515 St. Catherine West
Montreal, Quebec
H3G 1M8