Review of plane grating focusing for soft x-ray monochromators

Abstract

During the last 10 years various types of soft x‐ray monochromators have been developed, which are optically based on the plane grating focusing condition introduced in 1980. These instruments as well as those using the original 1980 optical configuration are reviewed and compared to the other type of high performance soft x‐ray gratingmonochromator, the Rowland circle based spherical gratingmonochromator (SGM). Performance data of a plane gratingmonochromator (HE‐PGM‐3), which was recently commissioned at BESSY and which offers a broad spectral range (40–2000 eV) and very high spectral resolution (up to E/ΔE∼10 000) are given in more detail. The performance of grating and crystal monochromators is compared in the 1–2 keV photon energy range.