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X-RAY RUNS: Apply for Beamtime

2017  May 17 - Jun 29

2017  Nov 1 - Dec 21

Over the past decade electronic area detectors have brought entirely new capabilities and efficiencies to x-ray science and have had a revolutionary impact on biological studies. A joint collaboration between the Biophysics Group in the Cornell Physics Department lead by Prof. Sol Gruner and CHESS is developing a new generation of large area electronic detectors called Pixel Array Detectors (PADs). This integrating detector is capable of capturing full-frame images with microsecond exposures having accuracy better than 1%. The PAD consists of a silicon layer, which absorbs the x-rays, bump-bonded onto a CMOS electronics chip in which each pixel has its own processing, storage, and readout integrated electronics. Having on-chip storage for eight full-frame images allows the device to be used in a "streak-camera" mode to capture x-ray data of fast transient phenomena.

During December 1998, the first prototype of a 92 ยด 100 PAD was successfully operated at the CHESS D1 beamline for microsecond time-resolved x-ray diffraction test studies. Tests indicate signal performance characteristics are comparable to currently used x-ray detectors, but with a greatly improved time resolution. This prototype is a test module en route to a larger format detector suitable for dedicated operation.

PAD Prototype        
Prototype of the 92x100 PAD. The x-ray sensitive area is the square, mirror-like surface in the center of the picture. It holds an array of 92x100 Silicon pixel diodes, each a 150m m square pixel, for a total sensing area of 13.8 mm x 15 mm. The CMOS chip is bump-bonded beneath the Silicon pixel diodes array. The surrounding electronics components operate the x-ray detector and readout. During normal operation this device is enclosed in a light tight cryostat.