Diffraction efficiency of high line-density X-ray transmission gratings

X-ray transmission gratings with high line-density are key components of various high-resolution spectrometers. X-rays transmission gratings with 5000 l/mm are needed to diffract X-ray at 2.0-5.0 keV. To obtain the absolute efficiency of the 5000 l/mm gratings made domestically, the intensity ratio of diffraction peaks was experimentally measured for different energy X-rays radiated from the synchrotron radiation source. The duty cycle fitted by measured data was consistent with that obtained by the electron scanning microscope. Finally, the absolute diffraction efficiency was calculated via the rectangle cross-section model.