Beamline Optics

Overview

The beamline is sourced by an elliptically polarizing undulator (EPU63). A plane mirror M1 collects the diverging beam from the undulator and deflects the beam by 2° to reduce the heat load and cut off the high energy X-rays. The monochromator is Plane Grating Monochromator type, consisting a plane mirror M2 and three different variable line spacing (VLS) gratings. The monochromator energy-disperses X-rays, which is then focused vertically by the VLS gratings. Monochromatized X-ray beam is switchable into two branches by the ellipsoidal mirror M3 which also does the horizontal focus to the exist slit. At Branch A, X-ray beam is refocused by a KB mirror set to a sub-micro size. At Branch B, X-ray beam is refocused by a ZP to ~100 nm size in the nano-ARPES endstation. As a secondary choice, a small KB mirror set is planned to focus X-ray beam to ~100 nm in the nano-ARPES endstation.

Key Performance