Design and experimental evaluation of enhanced diffraction efficiency of lanthanum-based material coated laminar-type gratings in the boron K-emission region
| Autor: | Masami Terauchi, Hiroyuki Sasai, Tetsuya Nagano, Tadashi Hatano, Alexander S. Pirozhkov, Nobukazu Hayashi, Masato Koike |
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| Rok vydání: | 2021 |
| Předmět: |
Diffraction
Materials science Grazing incidence diffraction business.industry Analytical chemistry Solid angle Type (model theory) Diffraction efficiency 01 natural sciences Atomic and Molecular Physics and Optics Synchrotron law.invention 010309 optics Optics Angle of incidence (optics) law 0103 physical sciences Electrical and Electronic Engineering business Engineering (miscellaneous) Diffraction grating |
| Zdroj: | Applied optics. 60(16) |
| ISSN: | 1539-4522 |
| Popis: | Numerical and experimental studies have been performed to evaluate the enhancement of diffraction efficiency of diffraction gratings around B K -emission by overcoating lanthanum series layers on conventional metal-coated laminar-type gratings. We propose an optical design method based on the concept of spectral flux given by collection efficiency and diffraction efficiency. A diffraction grating with a small angle of incidence provides an advantage to soft x-ray spectrographs because it collects the emission at a larger solid angle compared to that of conventional grazing incidence diffraction gratings. Numerical calculations indicated that La and L a F 3 were promising as overcoating materials on a laminar-type Ni-coated diffraction grating, and we performed an experimental study using L a F 3 and La/C overcoatings, considering their producibility and durability. The diffraction efficiencies were measured using a reflectometer at a synchrotron facility. The diffraction efficiencies observed at 183.4 eV were 29.4% and 34.3% at angles of incidence of 85.1° and 84.9° for N i / L a F 3 and Ni/La/C gratings, respectively. |
| Databáze: | OpenAIRE |
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