開催報告：10月23日　日米高エネルギー密度科学セミナー（Speaker: Dr. Dr. Iwata, ILE & Dr. Higginson, LLNL）

今回は特別企画で、日米両サイドから２名の研究者の方から、米国・日本を行き来し共同研究をした時の経験を、楽しいかったこと、やりがい、チャレンジングなことなど研究成果だけでなく、お話いただきました。

講師：　岩田夏弥先生（阪大レーザー研）
タイトル：kJ PWレーザープラズマ物理の日米共同研究での経験
（理論からNIFディスカバリーサイエンス実験までいかにしてたどり着いたか）

講師：　Drew Higginson博士（LLNL）
タイトル：サバティカルで日本(レーザー研)に滞在した経験が私に与えたインパクト
（研究、教育活動、そして家族と体験した日本文化について）

———- ———- ———- ———-
–Japan Speaker–
Professor Natsumi Iwata
Institute of Laser Engineering at Osaka University

–Title–
From theory to NIF Discovery Science experiment:
US-Japan collaboration on kJ PW laser plasma physics

–Abstract–
In this seminar, I will talk about my experience of US-Japan research collaboration related to laser-driven ion acceleration. The collaboration with LLNL researchers started based on our mutual interest in kilojoule petawatt laser-plasma interaction (LPI). Both kJ lasers, LFEX at ILE and NIF-ARC at LLNL that have multi-picosecond (ps) pulse durations, are pioneering a new regime of LPI where efficient electron heating and ion acceleration beyond the scaling used in the sub-ps regime have been observed. Our theoretical collaboration found a unique mechanism of fast electron confinement in the laser spot area, which appears only in the multi-ps regime [1]. We conducted a NIF Discovery Science experiment to clarify the confinement effect on ARC laser driven ion acceleration in 2023 and 2024. [1] N. Iwata et al., Phys. Rev. Research 3, 023193 (2021)

———-

–US Speaker–
Dr. Drew Higginson
Lawrence Livermore National Laboratory (LLNL)

–Title–
The impact of my sabbatical in ILE, Japan

–Abstract–
Dr. Drew Higginson will share insights from his summer as a guest associate professor at Osaka University through the Professional Research or Teaching (PRT) Leave Program at LLNL. His research focused on the kinetics of alpha heating and included teaching/developing a curriculum spanning basic plasma physics to advanced high energy density science (HEDS). This exercise recalled his graduate student days and deepened his understanding of essential HEDS concepts. Beyond academia, Dr. Higginson and his family immersed themselves in Japanese culture and culinary highlights, including a seafood barbecue prepared by an ama diver. These interactions underscored the value of the PRT program for fostering global academic collaboration. Dr. Higginson encourages others to learn more about the unique benefit of the PRT program and will discuss the specifics of his experience.

Work performed under the auspices of the U.S. DoE by Lawrence Livermore National Lab under Contract DE-AC52-07NA27344. LLNL-ABS-870483