UVSOR-III, at the Institute for Molecular Science in Okazaki, Japan, is a compact low-energy synchrotron — one of the world’s most advanced sources of vacuum-ultraviolet and soft X-ray light, prized for its high brightness despite its small size.
The UVSOR facility began operating in 1983 and, after two major upgrades, runs today as UVSOR-III. Its 750 MeV storage ring is just 53 m around, yet a low emittance of about 17 nm·rad and top-up operation at 300 mA make it a remarkably bright source in the VUV and soft X-ray range. The facility belongs to Japan’s Institute for Molecular Science (IMS), an inter-university research institute within the National Institutes of Natural Sciences.
At a glanceFacility profile
- Location
- Okazaki, Aichi Prefecture, Japan
- Operator
- Institute for Molecular Science (IMS), National Institutes of Natural Sciences
- Type
- Compact low-energy VUV / soft X-ray synchrotron
- Energy
- 750 MeV
- Circumference
- 53 m
- Beam current
- 300 mA (top-up operation)
- Beamlines
- 14 in operation, on six undulators and eight bending magnets
- First operations
- 1983
- Website
- uvsor.ims.ac.jp
The scienceWhat researchers do here
UVSOR-III is built for the physics and chemistry of electrons. In-vacuum undulators feed high-brightness VUV and soft X-ray beamlines used for soft X-ray absorption and photoelectron spectroscopy, including in situ and operando measurements of chemical and life-science samples. Variable-polarisation undulators drive angle- and spin-resolved photoelectron spectroscopy for solid-state physics, and since 2020 a momentum microscope has added a powerful new way to map electronic states. The facility also produces light from the terahertz region to tender X-rays, and even laser-Compton gamma rays.
Small ring, big reach: a compact low-energy source whose brightness rivals far larger machines for VUV and soft X-ray science.
Access for researchers
Applications to use UVSOR are accepted twice a year, with deadlines usually around mid-June and mid-December. Depending on the beamline, time may be requested for the full year or for either half. Proposals are reviewed on scientific merit.