The 12.2.1 endstation is essentially a Bruker laboratory diffractometer and a PHOTONII CPAD detector running shutterless coupled to a brighter X-ray source, an ALS superconducting bending magnet. The diffractometer has been mounted vertically, with the 2q and w rotation axes parallel to the plane of polarization of the beam.
Using a proprietary system has enabled users who are familiar with the Bruker system to work autonomously almost immediately.
A channel-cut Si(111) monochromator with an energy range of 6-17 keV is used. It is located 6 m away from the x-ray source . The second surface of Channel cut is offset to reduce vertical beam motion on mirror as energy is changed. The monochromator crystal is cooled to around -100 ˚C using a Joule-Thomson refrigerator. At this temperature the expansion coefficient of silicon is near zero and the heat conductivity is very good.
The x-rays are focused with a toroidal mirror (7 m away from the x-ray source) that produces a 1:1 beam focus in the experimental hutch, 14 meters away from the x-ray source. 4 mrad vertical angle gives an energy cutoff of 18 keV.