Search

A monolithic Wolter-type mirror with large acceptance, achromatism and small comatic aberration was designed and evaluated at the soft X-ray beamline BL25SU of SPring-8., A focusing optics that can provide a sub-micrometre high-flux probe for soft X-ray micrometre-scale angle-resolved photoemission spectroscopy (ARPES) is proposed. A monolithic Wolter-type mirror with a large acceptance, achromatism and small comatic aberration was designed and evaluated. A focused beam size of 0.4 µm (vertical) × 4 µm (horizontal), a high throughput of 59% and a high tolerance of 1.6 mrad to the pitching error were realized at a photon energy of 1000 eV. A Wolter-type mirror can be practically employed as a stable sub-micrometre focusing mirror with high throughput in ARPES applications.

S. Matsuyama, T. Wakioka, H. Mimura, T. Kimura, N. Kidani, Y. Sano, Y. Nishino, K. Tamasaku, M. Yabashi, T. Ishikawa, and K. Yamauchi "Development of a one-dimensional Wolter mirror for an advanced Kirkpatrick-Baez mirror", Proc. SPIE 7802, Advances in X-Ray/EUV Optics and Components V, 780202 (27 August 2010); https://doi.org/10.1117/12.860405., SPIE Optical Engineering + Applications, 2010, San Diego, California, United States, To realize achromatic full-field hard X-ray microscopy with a resolution better than 100 nm, we studied an imaging system consisting of an elliptical mirror and a hyperbolic mirror. The figure accuracies of the elliptical and hyperbolic mirrors required to obtain diffraction-limited resolution were investigated using a wave-optical simulator, and then elliptical and hyperbolic mirrors were precisely fabricated, following the criterion of the figure accuracies. Experiments to form a demagnified image of a one-dimensional slit installed 45 m upstream were conducted using the imaging system at an X-ray energy of 11.5 keV at BL29XUL of SPring-8. The system could form a demagnified image with the best resolution of 78 nm. In addition, the field of view to obtain a resolution better than 200 nm was 4.2 micron. © 2010 SPIE.

High resolution imagery of the solar X-ray corona provides a crucial key to understand dynamics and heating processes of plasma particles there. However, X-ray imagery of the Sun with sub-arcsecond resolution has yet to be conducted due to severe technical difficulty in fabricating precision Wolter mirrors. For future X-ray observations of the Sun's corona, we are attempting to realize precision Wolter mirrors with sub-arcsecond resolution by adopting advanced surface polish and metrology methods based on nano-technology to sector mirrors which consist of a portion of an entire annulus. Following fabrication of the first engineering mirror and subsequent evaluation on the X-ray focusing performance in 2013, the second engineering mirror was made with improvements in both precision polish and metrology introduced. Measurement of focusing performance on the second mirror at SPring-8 synchrotron facility with 8 keV X-rays has demonstrated that the FWHM size of the PSF core reached down to 0.2" while its HPD (Half Power Diameter) size remained at ~3" due to the presence of small-angle scatter just outside of the core. Also, there was notable difference in the focal length between sagittal and meridional focusing which could have been caused by an error in the sag in the meridional direction of

An achromatic and high-resolution hard X-ray microscope was developed, in which advanced Kirkpatrick-Baez mirror optics with four total-reflection mirrors was employed as an objective. A fine test pattern with a 100 nm feature size could successfully be resolved. Full-field imaging, in combination with X-ray absorption near edge structure (XANES) spectroscopy, was used to characterize tungsten particles. XANES spectra were obtained over the entire observation area, showing good agreement with the XANES spectrum of pure tungsten.

Compact advanced Kirkpatrick–Baez optics are used to construct a microscope that is easy to align and robust against vibrations and thermal drifts. The entire length of the imaging mirror system is 286 mm, which is 34% shorter than the previous model. A spatial resolution test is performed in which magnified bright-field images of a pattern are taken with an X-ray camera at an energy of 10 keV at the BL29XUL beamline of SPring-8. A line-and-space pattern having a 50- nm width could be resolved, although the image contrast is low.

S. Matsuyama, N. Kidani, H. Mimura, J. Kim, Y. Sano, K. Tamasaku, Y. Kohmura, M. Yabashi, T. Ishikawa, and K. Yamauchi "Development of a one-dimensional Wolter mirror for achromatic full-field x-ray microscopy", Proc. SPIE 8139, Advances in X-Ray/EUV Optics and Components VI, 813905 (28 September 2011); https://doi.org/10.1117/12.892987., SPIE Optical Engineering + Applications, 2011, San Diego, California, United States, We investigated a one-dimensional Wolter mirror (which consists of an elliptical mirror and a hyperbolic mirror) with the aim of developing an achromatic full-field X-ray microscope with a resolution of better than 50 nm. X-ray mirrors were ultraprecisely fabricated by elastic emission machining to give a figure accuracy of 2 nm (peak-to-valley). A one-dimensional Wolter mirror that had been precisely constructed was evaluated in terms of the point-spread function at the center of the field of view (FOV) and the FOV at an X-ray energy of 11.5 keV at BL29XUL of SPring-8. It was found to have a minimum resolution of 43 nm and a FOV equivalent to 12.1 μm. These results are highly consistent with calculation results. © 2011 SPIE.