2022 Fiscal Year Final Research Report
Development of sensitive electric field measurement method by two-stage laser induced fluorescence technique with tunable diode lasers
| Project/Area Number |
20K03890
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 14010:Fundamental plasma-related
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| Research Institution | Japan Healthcare University |
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Principal Investigator |
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 電界計測 / 水素プラズマ / レーザー誘起蛍光法 / キャビティリングダウン吸収分光法 / ラムディップ |
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| Outline of Final Research Achievements |
The purpose of this study is to develop a highly sensitive electric field measurement method in plasmas using a tunable diode laser as a light source, which enables experimental measurement of electric field structures in sheaths and pre-sheaths. In the two-stage laser-induced fluorescence method for hydrogen atoms, it is found that spectra with sufficient wavelength resolution cannot be obtained due to the migration of populations between fine structure levels and thermalization of atomic velocity distribution in the n=3 state, which is the intermediate level. The SCAR method, which introduces saturation evaluation into cavity ring-down absorption spectroscopy (CRDS), provides high wavelength-resolution spectra due to ram-dip even for low-density hydrogen plasmas, and it is confirmed that ram-dip is shifted and split by the Stark effect due to the sheath electric field.
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| Free Research Field |
プラズマ計測
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| Academic Significance and Societal Importance of the Research Achievements |
本研究で導入したSCAR法では高い電界計測感度と吸収感度を実現することが可能で、より低密度の水素プラズマや水素を一部含む混合プラズマ、トレーサーとして微量の水素を含むプロセスプラズマにおけるシース・プレシース領域の電界構造の解明によってプラズマプロセスの高度化やシミュレーションにおけるプラズマモデルの精密化への寄与が期待できる。
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