Ultra-high speed burst-mode imager for multi-frame radiography

Abstract

A 720×720 pixel hybrid-CMOS imager was fabricated by Rockwell Scientific (now Teledyne Imaging Sensors). Several cameras have been in operation for 5 years, in a variety of static and dynamic experiments, at the 800 MeV proton radiography (pRAD) facility at the LANSCE accelerator. The cameras can operate with a per-pulse adjustable inter-frame time of 250 ns to 2 s, and with an exposure/integration-time as short as 150 ns. With 80 ms total readout time, the imager can be externally synchronized to 0.1–5 Hz, 50-ns wide proton beam pulses, and record 1000-frame radiographic movies of 5-to-30 min duration. The effectiveness and dependence of the global electronic shutter on the pixelated Si photo-sensor bias voltage is discussed. The spatial resolution dependence of the full imaging system on various monolithic and structured scintillators is presented. We also present features of a new-generation 10-frame, 1024×1024 pixel, 50-ns exposure, 12-bit dynamic range imager, which is now in the design phase.