News

From November 2 to 4, we hosted the 27th East Asia Submillimeter-wave Receiver Technology Workshop (EARW2026) at the Okayama Convention Center, jointly with the RIKEN–NICT Joint Workshop on Terahertz Technology 2026. Assoc. Prof. Adachi in our lab served as chair of the local organizing committee, and our students did a great job helping out at the registration desk and with running the venue.

About 100 researchers from Japan and abroad gathered for three days of discussion on receiver technologies for millimeter, submillimeter, and terahertz waves. These technologies are at the heart of our own research, including CMB polarization observations with the Simons Observatory and LiteBIRD and dark matter searches with millimeter-wave receivers (DOSUE-RR). Talking directly with the East Asian receiver development community was a valuable and inspiring experience, especially for our students.

On the final day, we also held a tour of the Seimei Telescope and the 188 cm reflector in Asakuchi City, Okayama Prefecture. Many thanks to all the participants and to everyone who helped make the workshop possible.

Kento Kakinoki (M2) and Taichi Fukushima (M1) from our laboratory stayed at the High Energy Accelerator Research Organization (KEK) from October 13 to 26.

During their stay, they conducted evaluation experiments on the superconducting detectors that are the focus of their research, using a dilution refrigerator available at the facility.

They also had opportunities to interact with students and researchers from various universities and research institutes, making the two-week stay a valuable and rewarding experience.

Associate Professor Shunsuke Adachi of our laboratory conducted a pilot experiment at the National Institute for Fusion Science (NIFS) in Toki, Gifu Prefecture, as a first step toward searching for a hypothetical particle called the axion. The experiment was carried out in collaboration with the Sakurai Laboratory, Faculty of Engineering, Suwa University of Science.

Axions are a leading candidate for dark matter and are expected to convert into photons in a strong magnetic field. Our laboratory runs DOSUE-RR, a dark matter search experiment using millimeter-wave receivers, and we are applying this technology to detect the faint millimeter-wave signals that axions would produce in a magnetic field.

NIFS has expertise in large, powerful superconducting magnets developed to confine fusion plasma. Using one of these magnets, we tested whether our millimeter-wave receiver operates properly under extreme conditions: a cryogenic temperature of about −269 °C (approximately 4 K) and a strong magnetic field of 8 tesla, roughly 160,000 times that of Earth.

Building on these results, we aim to carry out a full-scale axion search.

The LiteBIRD face-to-face (F2F) meeting was held at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, from October 12 to 16, 2026. Ishino, Takaku, and Ueyama attended the meeting.

During the meeting, Ishino gave an oral presentation on mission requirements and related topics, while Ueyama presented her research results in a poster session. The poster session provided a valuable opportunity to explain her research in English and exchange ideas with international researchers.

A social dinner was also held at a restaurant during the meeting, where participants enjoyed a meal and strengthened their connections with researchers from Japan and abroad.

Associate Professor Yuki Inoue of the Department of Physics at National Central University in Taiwan visited our laboratory from September 28 to 29, 2026.

Professor Inoue is an alumnus of our laboratory and is currently an Associate Professor in the Department of Physics at National Central University. His research primarily focuses on gravitational waves, and he is involved in CHRONOS, a project aimed at gravitational-wave observation.

On the afternoon of September 29, Professor Inoue gave a seminar. Although his stay was brief, the students gained valuable inspiration for their research through discussions with him and his seminar.

On Friday, September 25, 2026, the 3rd Space Science Workshop was held at Okayama University of Science. Students from the Particle Physics Laboratory and the Theoretical Cosmology and Gravity Laboratory at Okayama University of Science, as well as from our laboratory, gave talks on their respective research.

Participants discussed one another’s research and exchanged ideas, making it a very fruitful workshop.

Many thanks to everyone at Okayama University of Science for hosting the event!

From September 14 to 17, 2026, Professor Ishino, Ikuma (D2), Kakinoki (M2), Fukushima (M1), and Ueyama (M1) gave presentations at the Annual Meeting of the Physical Society of Japan, held at the University of Tokyo.

Each of them presented the results of their research to an audience of many researchers and students. The presentations were followed by insightful and thought-provoking questions from the audience, providing valuable perspectives on their work.

They also had the opportunity to attend many presentations by other researchers and students, gaining a great deal of knowledge and inspiration.

Overall, the conference provided an excellent opportunity to reflect on the progress of their research, summarize what they had accomplished so far, and identify new challenges and directions for future work.

Prof. Eiichiro Komatsu of the Max Planck Institute for Astrophysics (MPA) in Garching, Germany, is staying with our laboratory for a month, from 3 to 30 September 2026.

Prof. Komatsu is Director of the Physical Cosmology department at MPA. Working on both the theory and the data analysis side, he has led the field in using the cosmic microwave background (CMB) and the large-scale structure of the Universe to probe inflation and the origin of the accelerating expansion of the Universe.

During his stay, he and the members of our group are discussing the science and analysis methods of CMB experiments, including the LiteBIRD satellite and the ground-based Simons Observatory, on a daily basis. LiteBIRD passed the second Mission Definition Review this June and has now entered a phase of more detailed instrument design and refinement of the data analysis methods. His extended visit therefore comes at an excellent time as we build the framework to extract the maximum scientific return from the data.

Kento Kakinoki (M2) and Taichi Fukushima (M1) from our laboratory stayed at the High Energy Accelerator Research Organization (KEK) from July 27 to August 10.

During their stay, they conducted evaluation experiments on the superconducting detectors that are the focus of their research, using a dilution refrigerator available at the facility.

They also had opportunities to interact with students and researchers from various universities and research institutes, making the two-week stay a valuable and rewarding experience.

LiteBIRD, a JAXA-led international space mission, has successfully passed Mission Definition Review #2.LiteBIRD aims to precisely measure the polarization of the cosmic microwave background and test the theory of cosmic inflation, which is thought to have occurred before the hot Big Bang.In this project, the Okayama University group has played a crucial role in connecting the scientific objectives with the detector development. To maximize the mission’s scientific return, the group has evaluated systematic effects that could limit observational performance and established a requirements flow-down framework for determining the design specifications of the instruments. These contributions also played a major role in the successful completion of this review.LiteBIRD will now proceed to the next phase, in which the team will further develop the detailed instrument design and advance data-analysis methods. Through these efforts, we will establish a framework for extracting the greatest possible scientific return from the data expected to be obtained by LiteBIRD.
For further details, please visit the Institute of Space and Astronautical Science website at the link below.
https://www.isas.jaxa.jp/missions/spacecraft/future/litebird.html