The ESRF has operated a high-resolution powder diffraction beamline for users since May 1996. Originally built on bending magnet BM16, the beamline has been relocated twice, to ID31 in 2002, and to ID22 in 2014. Following the EBS upgrade, ID22 has been equipped with a u26 in-vacuum undulator, giving X-rays in the range 6-75 keV (l » 2.07-0.165 Å). Measurements are routinely made at 0.354 Å (35 keV) unless there is a specific need to measure elsewhere. This relatively high energy for powder diffraction studies means that essentially all samples can be measured in a spinning thin-walled glass capillary, thereby reducing potential problems associated with preferred orientation.

 

The diffractometer’s nine-channel Si 111 multi-analyser stage has also been upgraded to a thirteen-channel version with a Dectris Eiger2 X 2M-W CdTe pixel detector that receives the X-rays transmitted by the analyser crystals. By exploiting the axial resolution this imparts to the measurements, the peak-shape asymmetry that occurs at low diffraction angles for high-resolution measurements has been eliminated leading to higher angular resolution than previously possible, and improved statistical quality at higher diffraction angles.

To get more insights about ID22 capabilities, join the webinar on Thursday 21 March 2024! Registration open here.