Associate Professor Yoshinori Enomoto of KEK Accelerator Laboratory Receives IEEE NPSS PAST Award
Dr. Yoshinori Enomoto, Associate Professor at the Accelerator Laboratory of the High Energy Accelerator Research Organization (KEK), has been selected as a recipient of the 2025 Particle Accelerator Science and Technology (PAST) Award from the IEEE Nuclear and Plasma Sciences Society (NPSS). This prestigious award is presented to individuals who have made significant contributions to the development of particle accelerator science and technology. The PAST Award is given to two recipients every 18 months during an international conference held in North America.
Associate Professor Yoshinori Enomoto
Dr. Enomoto was recognized for his critical contributions to injector linac technology, particularly the development of pulsed magnet systems and positron production.
After contributing to several major projects at the European Organization for Nuclear Research (CERN) and the Institute of Physical and Chemical Research (RIKEN), Dr. Enomoto joined KEK’s electron-positron injector group in 2015. There, he led the development of a wide range of accelerator components, including pulsed magnet systems, magnet power supplies, mechanical supports, alignment systems, and a positron production system. As this period was the later stages of the SuperKEKB injector upgrade, he was tasked with some of the most technically demanding systems. The KEK electron-positron injector serves not only SuperKEKB, but also two synchrotron radiation facilities, Photon Factory (PF) and PF-AR. During the upgrade, beam injection to these light sources had to be maintained, requiring careful planning and construction. Dr. Enomoto demonstrated strong leadership and engineering expertise under these challenging conditions.
In the pulsed magnet system development, Dr. Enomoto coordinated multiple teams to plan, construct, and operate more than 100 pulsed focusing and steering magnets. These systems played a key role in the successful start of simultaneous top-up injection into five storage rings in 2019. They allowed the injector to accelerate highly distinct beams every 20 milliseconds, an essential function for achieving both high-efficiency injection into the short-lifetime SuperKEKB ring and continuous injection into the synchrotron radiation facilities, enabling simultaneous high-performance experiments in both particle physics and photon science.
Since 2022, Dr. Enomoto has been affiliated with the Innovation Center for Applied Superconducting Accelerators (iCASA), where he leads the development of a positron production system for the International Linear Collider (ILC). He is developing the system based on his prior experience in which he has overcome persistent electrical discharge issues in a pulsed high-magnetic-field device (flux concentrator) for SuperKEKB by carefully selecting appropriate materials. The ILC positron source project aims to handle approximately 40 times the beam power compared to SuperKEKB and produce unprecedented average-intensity positrons. In particular, the team is tackling the challenge of developing a water-cooled, ultra-high vacuum-compatible rotating target that can operate reliably in a high-radiation environment, an uncharted but promising technological frontier. Once established, this technology could be applied to a wide range of high-power target systems beyond positron sources, playing a vital role in next-generation accelerator performance.
KEK has a long history in high-intensity positron source development and operation, dating back to the TRISTAN project, making it one of the world’s leading institutions in this field. Leveraging this expertise, international collaborations are expanding beyond the ILC to other collider-based particle physics experiments as well.
Rotating target and flux concentrator for positron production, under development for the ILC
Positron source under development, showing the rotating target from the upstream
Cross-sectional view of the positron source under development. The left half is completed, and the remaining part is currently under construction
Dr. Enomoto’s approach of personally engaging in both scientific analysis and hands-on engineering to realize cutting-edge accelerator systems has been highly regarded, culminating in this award. The award ceremony will take place at the 2025 North American Particle Accelerator Conference (NAPAC25) in August 2025.
