Project partners to conduct research on divertor plasma for the FAST project aiming for fusion power generation demonstration in the 2030s
The University of Tokyo (UTokyo), Starlight Engine Ltd. (SLE), and Kyoto Fusioneering Ltd. (KF) announce that they have concluded a joint research agreement to conduct research on divertor plasma as part of the FAST project, which aims to demonstrate fusion power generation in the 2030s.
1. Joint Research Agreement Overview
As global competition to realize fusion energy intensifies, the private-sector–led industry–academia collaboration project FAST was launched in November 2024 with the aim of demonstrating fusion power generation in the 2030s. FAST adopts a tokamak-based plasma confinement approach, which is supported by the largest body of research and experimental data worldwide and enables effective cost and technology risk management. The project is led by SLE as the operating entity and is being advanced through close collaboration among leading fusion researchers from Japan, industrial partners including KF, and international partners.
In fusion energy power plants, stable operation under high heat-load conditions requires an appropriately designed divertor that can efficiently remove impurities from the plasma core. Achieving this requires a detailed understanding of plasma characteristics in the divertor region and the development of optimized divertor designs based on that understanding. Against this backdrop, the Graduate School of Frontier Sciences, UTokyo, SLE, and KF have concluded a joint research agreement to conduct research on divertor plasma.
Professor Shin Kajita of UTokyo is a leading researcher in the fields of plasma diagnostics and plasma–material interactions. His research group focuses on the development of plasma measurement techniques essential for plasma control, as well as on elucidating plasma interactions with plasma-facing materials. The group also conducts applied research on novel functional materials using metals and metal oxides whose surfaces have been modified by plasma exposure. In addition, Assistant Professor Yuki Hayashi, who previously worked at the National Institute for Fusion Science (NIFS), has extensive experience and expertise in research on detached divertor plasma, which is considered effective for controlling plasma flowing into the divertor region and reducing heat loads.
By combining the advanced expertise of Professor Kajita and Assistant Professor Hayashi with the engineering capabilities and project execution strengths of SLE and KF, the partners aim to establish optimized divertor designs and operational strategies best suited to the FAST project.
2. Joint Research Agreement Details
The research will be led by Assistant Professor Yuki Hayashi as Principal Investigator and aims to establish divertor designs and operational strategies suitable for FAST. The study will evaluate heat loads, particle transport, and plasma–wall interactions, all of which significantly influence divertor design and operational scenarios.
Specifically, the research will employ one-dimensional plasma transport simulations to examine the following topics:
・Evaluation of radiative cooling by impurity gas puff and recycling rates required to achieve target steady-state divertor heat loads
・Estimation of neutral particle fluxes to the first wall resulting from charge exchange processes
・Determination of allowable pedestal temperature and density conditions based on divertor heat-load boundary conditions
3. Comments from Project Leaders
Shin Kajita – Professor, Graduate School of Frontier Sciences, The University of Tokyo
Yuki Hayashi – Assistant Professor, Graduate School of Frontier Sciences, The University of Tokyo
We are pleased to be involved in the industry–academia collaboration project FAST through this joint research with Starlight Engine and Kyoto Fusioneering. Achieving fusion energy requires a deep understanding of plasma–material interactions. By leveraging our past research outcomes and expertise, we aim to contribute to the divertor design of FAST.
Kiyotaka Kikuchi – President & CEO, Starlight Engine Ltd.
The development of the components and systems that make up FAST requires close collaboration with researchers who possess extensive expertise. We are delighted to work with Assistant Professor Hayashi, who serves as the Principal Investigator, and Professor Kajita, an expert in plasma diagnostics and plasma–material interactions, on research into divertor plasma.
Kiyoshi Seko – President & COO, Kyoto Fusioneering Ltd.
The divertor is a critical component of a fusion power plant, and research on divertor plasma is essential for its design. By combining the outstanding expertise of Professor Kajita and Assistant Professor Hayashi, who are conducting leading-edge research in this field, with our own fusion plant engineering know-how, we are confident that this collaboration will advance an important aspect of the FAST design.
