大型放射光施設 SPring-8

Language：English

Speaker1：Dr. Lei Huang,

Affiliation：Optics&Metrology Group, Physical Sciences&Research Ops Division, National Synchrotron Light Source II (BNL)

Title：Optical Metrology and Fabrication for Synchrotron X-ray Optics at NSLS-II

Abstract：
The increasing demands of cutting-edge synchrotron radiation and free-electron laser facilities call for X-ray mirrors of exceptional precision: capable of preserving the diffraction-limited wavefront and focusing beams to the diffraction limit. Meeting these stringent requirements necessitates highly advanced optical metrology techniques that can reliably characterize mirror performance with high accuracy and over a certain measuring range. In this talk, we present our ongoing research and development efforts at the NSLS-II Optics and Metrology Laboratory to advance X-ray mirror metrology. This includes day-to-day metrology essential for beamline operations, as well as high-precision measurements used to guide ion beam figuring (IBF) processes for ultra-precise mirror polishing. We will discuss the technical challenges encountered, such as maintaining repeatability and extending the measurable range, and share how our tools and methodologies are evolving to meet these challenges. We will also outline future directions for enhancing metrology capabilities, including potential innovations in instrumentation, to further support the development of state-of-the-art X-ray optics for next-generation light sources.

■Speaker2：Dr. Tianyi Wang,

■Affiliation：Optics&Metrology Group, Physical Sciences&Research Ops Division, National Synchrotron Light Source II (BNL)

■Title2：Sub-Nanometer Ion Beam Figuring for Synchrotron Hard X-Ray Mirror Fabrication

■Abstract2:
Ion beam figuring (IBF) is an ultraprecision computer-controlled optical surfacing (CCOS) technique that removes material from an optical surface at the atomic level through physical sputtering. This method offers several advantages over conventional CCOS processes, including high determinism, stable tool influence functions (TIFs), no mechanical load force, minimal surface or subsurface damage, and reduced edge effects. Over the past decade, significant advancements have been made in IBF techniques for synchrotron X-ray mirror fabrication. These advancements encompass metrology, dwell time optimization, motion control, and process parameter optimization, aiming to achieve high figuring accuracy and rapid convergence to the desired surface height and slope profiles. The feasibility of using IBF to fabricate flat and off-axis aspherical mirror surfaces with height errors of ≤0.5 nm RMS and slope errors of ≤0.1 μrad RMS has been demonstrated, establishing IBF as a highly effective CCOS technique for the development of X-ray Kirkpatrick-Baez (KB) mirrors. This talk reviews and summarizes the key aspects of fabricating sub-nm synchrotron X-ray mirrors using IBF at NSLS-II.