Double-edge scan wavefront metrology and its application in crystal diffraction wavefront measurements

Autor: Fang Liu, Ming Li, Qianshun Diao, Zhe Li, Zhibang Shen, Fan Li, Zhen Hong, Hongkai Lian, Shuaipeng Yue, Qingyan Hou, Changrui Zhang, Dongni Zhang, Congcong Li, Fugui Yang, Junliang Yang
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of Synchrotron Radiation, Vol 31, Iss 5, Pp 1146-1153 (2024)
Druh dokumentu: article
ISSN: 1600-5775
16005775
DOI: 10.1107/S1600577524006222
Popis: Achieving diffraction-limited performance in fourth-generation synchrotron radiation sources demands monochromator crystals that can preserve the wavefront across an unprecedented extensive range. There is an urgent need for techniques of absolute crystal diffraction wavefront measurement. At the Beijing Synchrotron Radiation Facility (BSRF), a novel edge scan wavefront metrology technique has been developed. This technique employs a double-edge tracking method, making diffraction-limited level absolute crystal diffraction wavefront measurement a reality. The results demonstrate an equivalent diffraction surface slope error below 70 nrad (corresponding to a wavefront phase error of 4.57% λ) r.m.s. within a nearly 6 mm range for a flat crystal in the crystal surface coordinate. The double-edge structure contributes to exceptional measurement precision for slope error reproducibility, achieving levels below 15 nrad (phase error reproducibility < λ/100) even at a first-generation synchrotron radiation source. Currently, the measurement termed double-edge scan (DES) has already been regarded as a critical feedback mechanism in the fabrication of next-generation crystals.
Databáze: Directory of Open Access Journals
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