Design of a compact varied-line space grating monochromator for enhanced flux at MAXLAB

For soft x-ray fluorescence spectroscopy with selective energy excitation, it is desirable to have maximum flux at moderate resolution. A plane grating monochromator with varied line spacing can be used in the convergent beam of an ellipsoidal focusing mirror to provide moderate resolution with a large collection angle and minimum number of reflecting surfaces. We determine the design parameters for a varied-line-space grating monochromator to provide light in the 200-1000 eV range. The results of modeling are discussed with respect to the optimal choices of monochromator for our experimental requirements. A novel mechanical design is proposed for constructing the monochromator in a compact form with the minimum number of moving parts and alignments