Evaluation of X-Ray Reflectors by Optical Diffraction Patterns

Hayashi, Takayuki ; Okajima, Takashi ; Soong, Yang

关键词: COMPUTATION;    DIFFRACTION PATTERNS;    EVALUATION;    GRAZING INCIDENCE;    MIRRORS;    OPTICAL MEASUREMENT;    PARABOLIC REFLECTORS;    PHYSICAL OPTICS;    REFLECTORS;    X RAY OPTICS;   

RP-ID  :  GSFC-E-DAA-TN66143

学科分类：原子、分子光学和等离子物理

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Performance of X-ray reflectors affects that of X-ray mirrors. Modern X-ray mirrors have thousands of reflectors to gain large effective area. Evaluation of the reflectors is an important process in production of the mirrors. A diffraction pattern dominates reflector image when the parallel optical beam illuminates the reflector along its optical axis because the reflectors are used at grazing incident angles of around 1 deg and their effective width are 1–10 mm. A diffraction pattern from the entire reflector surface can be acquired at once with the aid of a lens. The diffraction pattern holds information of the surface profiles of the reflectors. To quantitatively evaluate the reflectors with the diffraction pattern, we created a diffraction pattern model by the wave optics with the ideal surface profile and fitted it to data. As a result, a correlation between fitting residual and the normal vector distribution of the surface profile was found. With our method, the reflectors can be evaluated and sorted out more efficiently.