Optimization of spherical grating monochromators operating with variable included angle for different applications

The concept of variation of the angle of deflection in a spherical grating monochromator allows to keep the defocus aberration at zero while keeping the entrance and the exit slit distances fixed. This report presents the optimization of this concept for different applications in which one would always like to work with maximum resolving power and photon flux while keeping the exit slit at a fixed position. Three designs are presented for medium resolution (E/ΔE = 3000) soft x-ray microscopy studies in the photon energy range 200–1200 eV and 20–300 eV and for high-resolution spectroscopy (E/ΔE≳10 000) in the larger range 20–800 eV.