High coherent flux at the NSLS-II coherent soft x-ray beamline

The optical design of the coherent soft x-ray (CSX) and fast polarization switching beamline at NSLS-II has been optimized to deliver photon flux in the range of 1012 − 1013 ph/s in the energy range from 200 to 2000 eV. Two identical APPLE-II undulators will be operated in two different modes: canted and phased. In the canted mode, one beam will be directed to the coherence branch and the other to the fast polarization switching branch. In the phased mode, the two undulators will be operated as a single device to deliver the highest coherence flux to the coherence branch. The monochromator for the coherence branch is a focusing variable line spacing plane grating monochromator designed to deliver a moderate resolving power (2000 to 3000). The horizontal focusing onto the exit slit will be performed with a cylindrical bendable mirror located downstream of the monochromator and having similar demagnification as the monochromator.