The primary optics are located in Optics Hutch 1 (OH1) and serve the rest of the beamline.  Energy selection is provided by a double bent crystal (Si 111) monochromator operating in horizontal Laue geometry. The maximum energy range available is from 18 – 140 keV, though operationally, ID11 is optimized to work at energies above 35 keV*.

Focusing of the beam can be achieved using an in-vacuum transfocator. With this, in EH3 (94 m) it is possible to focus throughout the entire energy range (the smallest focal spot achieved ~50 x 220 microns), and up to 75 keV in EH1 at 41 m (spot sizes~ 6 x 45 microns).

Other components within the hutch include an attenuator system (6 axes of 3 attenuators on each axis) and water-cooled slit systems of two types: one primary slit system for beam definition, and secondary slit systems for beam conditioning.

The optics hutch can be operated in a variety of different modes: direct beam (white/pink) or monochromatic beam and this can be with or without focusing. Since the transfocator is chromatic, the focused white beam has a limited band pass (~1%). The band pass for the monochromatic beam is determined by the curvature of the crystals and geometry, giving a rocking width which is approximately constant with energy.

It should be noted that the monochromatic beam is in the orbital plane of the synchrotron but is displaced by 10-15 mm horizontally from the undulator white beam. Therefore the transfocator focusing (and all the down stream y translations) are in-line with either the white or monochromatic beam at its respective off-set. This means users should contact the beamline staff if they desire to use a number of x-ray energies over a broad range to make sure each can be reached without necessitating a realignment of the whole beamline.