2017 March 15 - April 24
2017 May 17 - June 29
2017 BTR deadline: 04/17/17
2017 October 11 - December 21
2017 Proposal deadline: 08/01/17
2017 BTR deadline: 09/10/17
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 ´ 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.
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.