IER Special Seminar held at IER on March 27, 2026 (Dr. INOUE Mutsuo)

On Friday, March 27, 2026, the IER hosted a Special Seminar featuring Dr. INOUE Mutsuo from the Institute of Nature and Environmental Technology, Kanazawa University. The event was attended by 11 participants, including researchers and graduate students from Fukushima University.

Dr. Inoue presented his research on low-background gamma-ray spectrometry utilizing the cultural heritage of the Kaga Domain. At Kanazawa University, the former site of the Ogoya Mine, historically associated with the Yokoyama family, chief retainers of the Kaga Domain, is utilized as an underground laboratory to suppress interference from radon gas and cosmic rays. Furthermore, lead roof tiles from Kanazawa Castle dating back to the Edo period are repurposed as shielding material for germanium detectors. Ordinary lead contains the naturally occurring radionuclide ²¹⁰Pb, which interferes with low-level radioactivity measurements. However, since ²¹⁰Pb has a half-life of 22.3 years, virtually no ²¹⁰Pb remains in lead refined during the Edo period, making it arguably the most suitable lead available for use as a shielding material. In addition, he highlighted the use of other materials such as steel from the WWII battleship Mutsu and natural barium separated from barite in low-level radioactivity measurements. Dr. Inoue remarked that his research is underpinned not merely by the latest technological progress, but also by these diverse historical legacies.

After the presentation, various questions and comments were raised by participants.