Peripheral plasma diagnostics by electron spectroscopy of vibrationally-excited hydrogen molecules

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K05636
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plasma science
• Research Institution: Sophia University
• Principal Investigator: Hoshino Masamitsu 上智大学, 理工学部, 教授 (40392112)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 電子分光 / 衝突断面積 / プラズマ素過程 / 加熱分子

Outline of Final Research Achievements

In order to understand atomic and molecular fundamental processes in the low-temperature plasmas around nuclear fusion including the interactions among electrons, metal surfaces, and neutral hydrogen molecules, electron collision cross sections for vibrationally-excited molecules generated by interacting between metal surfaces and hydrogen molecules were measured quantitatively. First, the collision cross sections of pure gas phase hydrogen molecules and its isotope deuterium molecules at room temperature were more precisely measured than previous works as the reference values. Then, when the electron collision cross sections of hydrogens penetrated though the high temperature metal cylinder were also measured and compared with the reference values, the different trend of the cross sections have been clearly observed between the present results and that for the pure gaseous hydrogen predicted from the Boltzmann distribution at high temperature.

Free Research Field

原子分子

Academic Significance and Societal Importance of the Research Achievements

これまで核融合周辺プラズマや半導体プロセスにおけるプラズマモデリングの基礎データとして様々な原子分子衝突過程の衝突断面積が用いられてきた。特に電子衝突断面積については，純粋な気相原子分子標的，類似標的に対する理論値や予測値が主に使用され，定量的な実験データの少なさが問題であった。そこで今回，金属表面と水素分子の相互作用で生成された励起水素分子の電子衝突断面積の定量データ，および室温で測定された基準となる純粋気相分子の精密データを測定し，高精度なプラズマモデリングを実行する上で必要不可欠なデータを得ることで，今後より現実に近いシミュレーションに基づいたプラズマの詳細な理解が期待される。