Beamline Optics

Overview

The Energy Conversion and Astrochemistry Photoionization Mass Spectrometry Beamline comprises two branches: a white light branch (WB) and a monochromator branch (MB). The white light branch utilizes an undulator for monochromatization, delivering high-flux white light beams to Experimental Station 1. The monochromator branch employs gratings for monochromatization, providing monochromatic light to Experimental Stations 2 and 3, with two plane variable-line-spacing gratings installed to accommodate different experimental requirements. The two branches are switched via the deflection mirror M0 and operate on a time-sharing basis. A Monk-Gillieson (MG) monochromator design is adopted. M2 serves as the pre-focusing mirror of the monochromator, and G is the plane variable-line-spacing grating. Together, they form the MG monochromator. During wavelength scanning, only the rotation of the grating axis is required, resulting in a simple structure. This system features a straightforward design and, when coupled with an Undulator light source, directly uses the source as the entrance slit, facilitating high throughput.