A high-intensity proton beam accelerated in the J-PARC main ring (MR) is slowly extracted using third integer resonance and delivered to the experimental hall. A critical issue in slow extraction (SX) is beam loss during the extraction process. An achromatic dynamic bump scheme has provided extremely high extraction efficiency. Beam instability during the debunching process has been suppressed through sophisticated RF manipulations. Spill feedback and transverse RF techniques have improved the time structure of the extracted beam. A beam power of 92 kW was achieved in combination with a diffuser shadowing technique. The 8 GeV bunched slow extraction tests for the muon-to-electron conversion experiment (COMET Phase-I) have been successfully conducted. This paper provides an overview of J-PARC SX and related hardware in Part I and reports on the achieved SX beam performance in Part II.

Institute for Molecular Science celebrated its 50th anniversary in April 2025. A synchrotron light source, UVSOR, was installed there in the early 1980s. It has been leading the synchrotron radiation science in Japan alongside the Photon Factory (KEK), which was built around the same time. UVSOR already passed its 40th anniversary two years ago. It has been supplying low-energy synchrotron light, covering the vacuum ultraviolet and soft X-ray regions as well as infrared and terahertz waves, to researchers in a wide range of fields both in Japan and overseas. It has undergone two major upgrades to address aging and improve performance. The emittance of the electron beam, which determines the brightness of the synchrotron light, has improved by approximately one order of magnitude from its original value. The number of undulators that can take advantage of this high brightness characteristic has been increased from the original two to six. Furthermore, top-up operation, which has become the standard operating method for modern synchrotron light sources, has also been introduced. Taking advantage of the unique features of a small, agile facility, UVSOR has produced many pioneering results in the development of various light source technologies, including free electron lasers, space-time structured light, and laser Compton scattering gamma-rays. However, the fight against aging and declining competitiveness is never-ending, and the time has come to aim for the realization of the next upgrade plan.

The White Neutron Source operated at the Research Center for Nuclear Physics, Osaka University is presented. This facility is one of the few white neutron irradiation test facilities in the world that is certified in JEDEC JESD-89A Test Standard and is used for soft error testing of semiconductor devices. Since its launch in 2004, it has been utilized by semiconductor-related companies both in Japan and overseas and plays an important role as a technological foundation for realizing Society 5.0.

In recent years, the development of commercial spacecraft has accelerated globally, and in Japan as well, privately-led satellite launches—particularly of small satellites—have become increasingly active. As a result, the use of Commercial Off-The-Shelf (COTS) electronic components in spacecraft has progressed, driven by the need to reduce development costs and timelines. However, to ensure reliability in the harsh space radiation environment, the demand for radiation tolerance evaluation has surged. On the other hand, Japan’s domestic radiation testing infrastructure faces several challenges: the labor-intensive process of component selection, the lack of standardized testing and evaluation methods, the complexity of utilizing irradiation facilities, and issues related to equipment congestion and aging. These issues render the current system vulnerable to the expected surge in testing demand. This paper identifies these challenges based on insights from a study group involving 105 organizations across industry, academia, and government, as well as the results of a supply-demand survey. It then proposes a radiation testing platform centered around a shared access point for irradiation facilities, support functions, and a COTS component database. Furthermore, the paper discusses the potential ripple effects of this platform on emerging markets such as lunar exploration, next-generation satellite communications, and the global deployment of COTS components, illustrating its potential as an infrastructure that can enhance the international competitiveness of Japanese companies.