Introduction of High-precision X-ray Mirrors

Synchrotron radiation is artificial electromagnetic waves (light) generated when high-energy electrons traveling in a straight line inside a circular accelerator (synchrotron) have their trajectory bent by deflecting electromagnets. It includes wavelengths ranging from long infrared rays to short X-rays. A synchrotron radiation facility is an experimental facility where this synchrotron radiation can be utilized. Here, synchrotron radiation is used by extracting light of the required wavelength according to measurement and analysis purposes (this is called “spectroscopy”), but high-brightness (very bright) X-rays are used to illuminate the world of atoms and molecules at the nanometer level.

SPring-8, a large synchrotron radiation facility in Hyogo Prefecture that began operation in 1997, is called one of the world’s three major synchrotron radiation facilities, along with APS (Advanced Photon Source) in the United States and ESRF (European Synchrotron Radiation Facility) in Europe. It is equipped with a circular accelerator with a total circumference of 1,436m and 62 experimental locations called beamlines, and has achieved many excellent results from basic research to industrial applications through the world’s highest level of high-brightness synchrotron radiation provided there.

Various high-precision X-ray mirrors

The reflection surface of our high-precision X-ray mirrors is realized by Elastic Emission Machining (EEM), which enables atomic-level (0.1nm level) removal processing based on fundamental research at Osaka University, and Micro Stitching Interferometry (MSI) and Relative Angle Determinable Stitching Interferometry (RADSI), which enable shape measurement at the nanometer level over a wide range in the meter region.

A large synchrotron radiation facility can be compared to a “giant microscope.” To observe the world of atoms and molecules, we need strong light (X-ray) that illuminates the microscopic world inside the material. This can be realized using strong, high-luminance X-rays from a large accelerator with a special bending electromagnet.

The synchrotron radiation facility is a research facility where microstructures can be examined by applying synchrotron radiation to the sample material. Electrons emitted from the electron gun are accelerated to values close to the speed of light, and powerful radiation can be obtained by using a deflecting electromagnet and an insertion light source device. The synchrotron radiation travels from the storage ring to the experimental line (beam line) allocated radially and is used for diverse research and analysis.

SPring-8 is a large-scale synchrotron radiation facility that can produce the world’s highest performance synchrotron radiation. The ring has a total circumference of 1.5 km and 62 beamlines (of which 56 are in operation). SPring-8 is among the world’s highest level synchrotron radiation facilities, with Advanced Photon Source (APS) in the US and the European Synchrotron Radiation Facility (ESRF) in Europe, and has achieved excellent results from basic research to industrial use. Usually 4 to 10 X-ray mirrors are used in a beamline. We have delivered a number of mirrors to SPring-8 and the adjacent X-ray free electron laser facility SACLA.

Our high-precision X-ray mirrors are used in the beam line for the purpose of focusing, spectroscopy, and imaging. As an example of use, a high-precision KB mirror can be installed in front of a test sample, and X-rays can be focused at nano scale to achieve higher resolution.

Recent research results using synchrotron radiation include basic and applied research such as protein structural analysis of atomic arrangements, 3D structures of particles recovered from the asteroid Itokawa, structural determination of the regular growth of nanocrystalline composite thin films. It is also widely used in industrial fields such as visualization of the chemical state of platinum catalysts in fuel cells and new material development technology for high-performance tires.