The beamline adopts the light source generated by a 22 mm period in-vacuum undulator (IU22). A symmetric focal spot is generated by utilizing a two stage focusing strategy. The horizontal focusing mirror (HFM1) incorporated with a high precision slit 3 creates a horizontal virtual source. Followed by a second HFM2, the horizontal virtual source is projected back to the center of undulator to form a symmetric light source with a demagnification ratio around 627 in both vertical and horizontal direction.
High vacumn stainless steel tube
The Montel optics forms a nanometer-focal spot from two sequential reflections by two identical mirrors nesting side-by-side. The numerical aperture is thus enlarged, resulting a smaller diffraction-limit focal spot. The Montel optics is of essential advantage in obtaining larger working distance for accumulating multimodal X-ray probes, particularly for the present beamline with only moderate length (75 m).
In order to preserve the transversal coherence of light source, the entire beamline will be operated under vacuum environment.