In a nutshell:
Dr. Moriyama joined Kyoto Fusioneering (KF) in April 2023 as part of the Plasma Heating Division. Prior to his position at KF, he worked on experiments for the tandem mirror plasma confinement device GAMMA 10 at the University of Tsukuba. Then, he contributed to the JT-60 project at the Japan Atomic Energy Research Institute (JAERI), now known as the National Institutes for Quantum Science and Technology (QST).
Now, leveraging nearly four decades of experience in fusion energy research and development, he oversees testing for KF’s gyrotron systems and spearheads the establishment of a new technology development facility.
What first led you to work in fusion energy?
My journey into fusion energy began during my undergraduate years at the University of Tsukuba, when I joined a laboratory focused on fusion research in my fourth year. While selecting a lab and thinking about my graduation thesis, I learned that Tsukuba housed the GAMMA 10– the predecessor to the world’s largest tandem mirror plasma confinement device, GAMMA 10/PDX—leading me to learn more about fusion energy itself.
At the time, fusion energy was often described as a “dream energy source”, and I was strongly drawn to its immense scale and untapped potential. At the same time, there was a very tangible, hands-on aspect since I could operate large experimental devices myself. It was this duality—the grand vision combined with practical experimentation— that captivated me and led me to pursue fusion research.
Looking back, my childhood interests in physics and virtual worlds, sparked by books and television, may have also played a role in my decision to pursue fusion energy.
What kind of research did you work on in the lab at the University of Tsukuba?
In the lab, I measured high-energy particles to evaluate plasma temperature in the GAMMA 10 device and operated neutral beam injectors (NBI) to raise plasma temperature. The lab placed a strong emphasis on hands-on experimentation with equipment rather than theory alone, which gave me many opportunities to learn by doing.
As a result, I gained technical skills that go well beyond textbook knowledge— from handling vacuum systems, high-voltage power supplies, and machine tools, to even running overhead cranes. These experiences gave me a practical foundation that proved invaluable later in my career.
As I approached the end of graduate school, I felt a growing desire to conduct fusion energy research with larger, higher-performance devices. At that time, however, Japan had very few private companies—let alone startups—working in fusion energy, so I was considering working for a major manufacturer.
Then, our lab received a recruitment notice from the Japan Atomic Energy Research Institute (JAERI, now the National Institutes for Quantum Science and Technology or QST) which led to my pivotal decision to join the organization. I was genuinely excited when I realized I could fully immerse myself in fusion R&D in an environment dedicated to this research.
What were your responsibilities at JAERI and QST?
I worked on the large research tokamak called JT-60U, specifically focusing on the operation and technical development of ion cyclotron heating systems and electron cyclotron heating (ECH) systems used for heating plasma. This was when I began engaging extensively with the gyrotron systems that are now one of Kyoto Fusioneering (KF)’s core businesses.
Thanks to my lab experience, I adapted quickly to practical tasks such as operating cranes and high-voltage power supplies. However, unlike my previous work with high-energy particle diagnostics and NBI, plasma RF (radio frequency) heating theory for ion cyclotron and ECH systems was entirely new to me, and there was much to learn.
However, with guidance from senior researchers, I gradually built up my understanding of system principles and specifications.
Over time, I began proposing my own ideas for improving device performance. When my adjustments actually led to measurable improvements in gyrotron system performance, I felt deeply proud to have contributed to the project and gained newfound confidence as an engineer.
These successes motivated me further, and I started thinking constantly about how to improve device efficiency and obtain the data we needed. I also actively participated in expert meetings and committees, gathering insights on how to safely operate large-scale devices, enhance their durability, and optimize their overall performance.
As development progressed on JT-60SA— the successor to JT-60U, my experience and expertise was recognized and I was appointed manager of plant assembly operations. While I had assembled gyrotron systems before, this was my first time leading a team.
Unlike my previous roles where I could work independently, stepping into a leadership role made me feel the weight of responsibility— especially when results didn’t come easily. Coordinating on-site work around project schedules and maintaining team morale presented challenges unique to management. But, when experiments succeeded, the sense of accomplishment we felt as a team was even greater than when I achieved results on my own.
What makes fusion R&D interesting and rewarding to you after nearly 40 years?
The equipment used in fusion energy is not mass-produced. In many cases, we are building things that have never existed before, making it extremely difficult to achieve the ideal outcome on the first attempt. It requires perseverance and countless iterations to gradually approach the goal.
There were moments of frustration, but I was fortunate to work in environments where colleagues would come together to help search for solutions and encourage eachother to embrace new challenges. Being surrounded by people who truly understood the difficulty of testing large-scale equipment also gave me the reassurance that it was acceptable—even necessary—to keep experimenting patiently until results were achieved.
While working on unprecedented technology comes with challenges, the sense of accomplishment when a test or operation succeeds is incomparable. I am also motivated knowing that my work contributes to realizing fusion energy as a next-generation power source.
What motivated you to join KF?
JT-60SA is a national project, and working on it was deeply fulfilling. However, after experiencing both hands-on engineering and management throughout my career, I found myself drawn back to my roots—technical development of RF heating systems.It was around that time that I came across KF.
Looking into the company, I discovered that ECH is a core business area and that KF supplies gyrotron systems to research institutes and companies worldwide — systems that embody decades of Japanese research results and manufacturing expertise.
At KF, I felt that I could pursue what I truly wanted to do. Additionally, Dr. Sakamoto, whom I had worked with on gyrotron development at QST, was already playing an active role at KF leading its R&D. After speaking with him and learning more about the company, my decision to move only became stronger. I applied for a position at KF, and that brings me to where I am today.
What are your current responsibilities at KF?
As Head of the ECH Facility Department within the Plasma Heating Division, I manage a team responsible for building the infrastructure needed for gyrotron system development. This includes planning, designing, and procuring power supplies and other facilities, as well as leading the establishment of new development sites. I also stay involved in technical development and performance testing, drawing on my past experience in gyrotron development.
Currently, much of my time is devoted to launching the KF Shiga Innovation Factory, our first in-house gyrotron system development facility. This new R&D site will play a crucial role in future business and technological advancement since previously, gyrotron development and testing were conducted at external research institutions and partner facilities. Now, by consolidating these activities into a single location, we expect stronger collaboration among team members and significantly faster development cycles.
That said, starting from scratch requires tremendous effort. There is still much to be done, from installing equipment to setting up basic infrastructure. We are working closely as a team toward the goal of starting operations this fall. After that, we will proceed with high-voltage work and large equipment installation, followed sequentially by gyrotron development and performance testing.
Recently, we completed renovations of the office area and installed desks and chairs so it finally feels like a proper workplace. The R&D areas are also being built step by step, and the facility as a whole is gradually taking shape. Being on the ground and witnessing this transformation firsthand, I’m excited everyday to see how our location is coming together.
Since the KF Shiga Innovation Factory is fully managed by KF, we must also establish comprehensive operational rules and safety measures. As the person in charge, I work closely with Takako Matsudaira responsible for safety management to ensure that all equipment, facilities, and safety protocols are properly implemented to prevent accidents.
How does it feel working at KF?
Since joining KF, I have often been surprised by the speed at which things move. For example, a gyrotron system order progresses smoothly from customer inquiry to contract signing. I feel that departments are very well connected horizontally rather than vertically in silos. I’ve also been impressed by the business teams who, despite interacting directly with customers, possess deep technical knowledge. Having rarely encountered this type of role in other research institutions, their way of operating has been eye-opening.
Another major appeal of KF is that everyone approaches their work with positivity and genuine enthusiasm. Gyrotron systems are already in high demand, and our engineers are extremely busy. With another recent order from the US fusion startup, Realta Fusion, things will definitely get busier. Even so, team members continue to support and encourage one another, finding meaning and enjoyment in their work. It may be a given, but being part of such a team feels truly rewarding.
You seem to find your own work fulfilling as well.
Absolutely. I feel a sense of purpose e day at KF. From leading gyrotron R&D and testing to establishing a new facility and managing a team, I am involved in challenging but deeply fulfilling responsibilities.
When selecting a site for the new factory, there were many constraints to consider, such as sufficient floor space and specialized power infrastructure. There was a period when I traveled all over Japan to visit candidate locations while simultaneously drafting equipment specifications and planning layouts. The sheer amount of work was overwhelming at times. That’s why seeing the opening of the KF Shiga Innovation Factory announced in newspapers and news outlets filled me with a strong sense of accomplishment and joy.
Finally, what would you like to achieve at KF and in the fusion energy industry?
First, I want to build systems and frameworks that allow us to develop gyrotron systems more efficiently. Achieving optimal gyrotron performance requires fine-tuned adjustments that rely not only on theory but also on experiential, almost “craft-like” intuition that is difficult to put into words. By applying AI and automated control technologies, I hope to reduce dependence on individual expertise and enable the next generation of engineers to independently test and optimize gyrotron systems.
Second, I want to accelerate development by strengthening the skills of the entire team. For this, I share my experience and ways of thinking openly with our engineers. They are highly capable and can understand the intent behind decisions and move forward on their own with just a bit of direction. Watching them absorb knowledge and grow as engineers is incredibly rewarding, and it motivates me to keep pushing myself as well.
Through mutual improvement and whole-hearted dedication, we will continue to enhance our collective technical capabilities and drive the development of high-frequency, high-power, and high-efficiency gyrotron systems.
Ultimately, if KF gyrotron systems are eventually adopted by fusion energy plants around the world, nothing would make me happier.
