Keywords:diffraction grating, Boron, spectroscopic measurement
To meet with strong demands for the characterization of Boron at a single ppm level by soft X-ray emission grating spectrographs, we have been studying high diffraction efficiency gratings for B-K emission with transparent layer deposited on the surface. A Ni/La/C coated laminar-type grating has been fabricated and evaluated. Measured diffraction efficiency at B-K emission wavelength 6.76 nm was 37% at an angle of incidence of 84.2°. Enhancement of emission sensitivity by 5 times can be expected by high diffraction efficiency and low angle of incidence.