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X-RAY RUNS: Apply for Beamtime

2017  May 17 - June 29

2017  October 11 - December 21
2017  Proposal deadline: 08/01/17
2017  BTR deadline: 09/10/17

Figure 1


CHESS has recently acquired and commissioned a lightweight, high-resolution, high dynamic range area detector ideally suited for hard x-ray reciprocal space mapping of single crystal samples. The "PiXirad-1" module mounts easily on the 4-circle diffractometer at the A2 endstation, and is fully integrated into SPEC control. First-ever synchrotron tests and user experiments using the PiXirad were performed at CHESS during 2013. The defining advantage of this unit is the use of a CdTe crystal sensor instead of Si, which gives the PiXirad very high detection efficiency (> 90%) for photons with energies greater than 50 keV. This, combined with the inherently low noise of the single-photon-couting approach and a capability for fast-framing, makes for a uniquely useful detector for high energy single crystal diffraction. Early PiXirad experiments have focused on mapping charge-density modulations in high-Tc superconductors and diffuse phonon scattering in thermoelectric materials. CHESS staff are in negotiations with the manufacturer in an effort to develop a next generation version of this detector, which would be ~ 4X larger and offer in-pixel energy discrimination up to 100 keV.

The specifications for the PiXirad-1 are attached below:

Maximum frame rate:
Pixel pitch:
No. of Pixels:
Active area:
Well depth:
Linear counting:
100 Hz
60 microns X 52 microns
512 X 476
30.7 mm X 24.7 mm
15 bit
< 2e5 photons / pixel / sec



Submitted by: Jacob Ruff, CHESS, Cornell University