Time-resolved soft X-ray spectroscopy in liquid phase using a microfluidic chip

• Project/Area Number: 19H02628
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 30020:Optical engineering and photon science-related
• Research Institution: Kyoto University
• Principal Investigator: Adachi Shunsuke 京都大学, 理学研究科, 准教授 (90431874)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥17,810,000 (Direct Cost: ¥13,700,000、Indirect Cost: ¥4,110,000); Fiscal Year 2022: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2021: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2020: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2019: ¥11,180,000 (Direct Cost: ¥8,600,000、Indirect Cost: ¥2,580,000)
• Keywords: 軟Ｘ線パルス / アト秒科学 / 水の窓 / 軟Ｘ線 / マイクロフルイディクス / 超高速分光 / 超短パルスレーザー / 高次高調波 / 液相 / 過渡吸収

Outline of Research at the Start

マイクロフルイディクス(微小流体工学)を駆使して厚さ約1マイクロメートルの液体薄膜を生成し、水の窓(波長2.3～4.4ナノメートル)軟Ｘ線による液相の時間分解測定を実現させることを目的とする。水の背景信号に埋もれた溶質分子からの微かな信号を選択的に検出できる、分子の電子状態や構造の変化を鋭敏に検出できる、といった特徴は反応ダイナミクス研究に大きな革新をもたらす。

Outline of Final Research Achievements

Water window soft X-ray covering the K-absorption edges of C and N atoms were obtained by high-order harmonic generation using high-intensity infrared driving laser pulses. An apparatus has been developed to perform time-resolved soft X-ray spectroscopy in the liquid phase in the water-window region with 1-eV energy resolution and 20-fs time resolution, in which a liquid film jet of <1 um thickness is generated using a microfluidic chip.

Academic Significance and Societal Importance of the Research Achievements

水由来の背景信号に埋もれた溶質分子からの微かな信号を選択的に検出できる、分子の電子状態や構造の変化を鋭敏に検出できる、といった軟Ⅹ線分光の特徴は反応ダイナミクス研究に大きな革新をもたらす。溶質と溶媒の相互作用（溶媒効果）が化学反応にどのような影響を与えているかを明らかにし、さらには生命科学・環境科学・エネルギー等の幅広い分野に大きな影響を与えることが期待される。

Research Products

• [Journal Article] Methyl substitution effects on the non-adiabatic dynamics of benzene: lifting three-state quasi-degeneracy at conical intersections (2020)
  • Author(s): Adachi Shunsuke、Suzuki Toshinori
  • Journal Title: Physical Chemistry Chemical Physics Volume: 22 Issue: 5 Pages: 2814-2818
  • DOI: 10.1039/c9cp06164a
  • Peer Reviewed
• [Presentation] マイクロ流体チップを用いた液膜ジェットの生成と水の窓軟Ⅹ線過渡吸収分光への応用 (2023)
  • Author(s): 足立 俊輔、鈴木俊法
  • Organizer: レーザー学会学術講演会第43回年次大会
• [Presentation] マイクロ流体チップを用いた気・液相の軟Ⅹ線時間分解分光 (2023)
  • Author(s): 足立 俊輔、鈴木俊法
  • Organizer: 第70回応用物理学会春季学術講演会
• [Presentation] Soft X-ray time-resolved spectroscopy in gas and liquid phases using a microfluidic chip (2023)
  • Author(s): Shunsuke Adachi
  • Organizer: Conference on Laser and Synchrotron Radiation Combination Experiment 2023 (LSC2023)
  • Int'l Joint Research / Invited
• [Presentation] Shedding vacuum-UV light on non-adiabatic dynamics of molecules during and after passing through conical intersections (2021)
  • Author(s): Shunsuke Adachi
  • Organizer: Pacifichem 2021
  • Int'l Joint Research / Invited
• [Presentation] Non-adiabatic dynamics of benzene and its methyl derivatives studied by vacuum-UV time-resolved photoelectron spectroscopy (2019)
  • Author(s): Shunsuke Adachi, Takuya Suzuki, Shotaro Kudo, Toshinori Suzuki
  • Organizer: 34th Symposium on Chemical Kinetics and Dynamics
  • Int'l Joint Research
• [Presentation] 水の窓軟Ｘ線を用いた液相での過渡吸収分光実現に向けた装置開発 (2019)
  • Author(s): 足立 俊輔、矢野 晃生、鈴木 俊法
  • Organizer: 第80回応用物理学会秋季学術講演会