Three wiggler X-ray beamlines have been specially designed to share the total 13 mrad of the horizontal radiation from the 25-pole 1.8-tesla wiggler insertion device located at beam port 17. These beamlines take 3, 4, 3 mrads of horizontal radiation, respectively. There is only 1.5 mrad separation left between each two adjacent beamlines for all the hardware mechanism assemblies.
The 17A Triangular Crystal Monochromator(TCM) beamline takes the rightmost 3 mrad of the horizontal wiggler radiation. After the front-end, the photon beam passes through the Graphite filter located in the Filter Tank at 11 m, and then vertically focused by a water-cooled mirror located at 12.3m. The photon beam then pass through a Be-window at 15.5 m, the beamline 17C monochromator (C-mono) chamber at 16.9 m, and the second Be-window, and then enters the 17A monochromator (A-mono). The A-mono located at 18.8 m, which is a bent triangular Si(111) crystal miscut at 9 degrees, disperses and horizontally focuses the photon beam onto the sample location at about 6 meter downstream. The 17A-mono delivers fixed photon energy at 9.3 keV for regular diffraction measurement. The energy resolving power is less than 1000 because of the long source size viewed away from the centerline.