Abstract
The focusing of x rays is essential in various types of x-ray microscopy because the size and flux of the illuminating beam determine the spatial resolution and signal intensity, respectively. A system with grazing incidence mirrors allows highly efficient x ray focusing with beam dimensions on the nanometer scale. Tube-shaped mirrors with a large numerical aperture and high demagnification, including ellipsoidal mirrors and Wolter mirrors, have recently been developed for soft x-ray nanofocusing. However, these mirrors have low efficiency because they cannot focus the central part of the illumination beam. Here, we propose a two-stage focusing system, in which a ring-shaped beam formed by a ring-focusing mirror illuminates a quasi-Wolter mirror. A prototype of the system is experimentally constructed at beamline BL25SU-A of SPring-8. Observation of the wavefront error based on ptychography enables efficient alignment of the two mirrors. Using this alignment procedure, we achieve a spot size of less than 200 nm at 300 eV.
Original language | English |
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Article number | 0027118 |
Journal | Applied Physics Letters |
Volume | 117 |
Issue number | 15 |
DOIs | |
Publication status | Published - Oct 12 2020 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)