High efficiency multilayer coated laminar gratings with high line density for tender X-ray region

Driven by the demand of high efficiency and high resolution monochromators and spectrometers in the tender Xray range, high line density multilayer coated laminar gratings (MLLG) were designed, manufactured, and analyzed. Theoretical simulations displayed that a 5000 l/mm MLLG could realize high resolution at 3 keV and 40 times higher diffraction efficiency than the single-layer coated grating. For the first demonstration of the high line density MLLGs, two 3000 l/mm laminar gratings were fabricated and coated by Cr/C multilayers with different periodic thicknesses to achieve high efficiency (HE) and high resolution (HR) performance. For MLLGHE, a maximum efficiency of 54.5% was achieved at 4.4 keV. For MLLG-HR, relatively high efficiency of 23.1%- 38.6% were demonstrated with much stronger asymmetric diffraction in 2-4 keV, which can significantly increase the energy resolution of the system.