Post Collision Interaction and photoelectron recapture upon atomic and molecular photoionization

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05600
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Atomic/Molecular/Quantum electronics
• Research Institution: Sophia University
• Principal Investigator: Azuma Yoshiro 上智大学, 理工学部, 教授 (50270393)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: PCI / Synchrotron Radiation / Photoionization / Inner-shell / Photoelectron recapture

Outline of Final Research Achievements

Investigations of post collision interaction effects were pursued with experiments conducted at synchrotron radiation facilities including SOLEIL in France and SPring-8 in Harima. Measurements were performed by auger electron spectroscopy with high-resolution hemispherical electron analyzers. Very interesting results were obtained on three fronts including 1. The discovery of conjugate auger recapture peaks dominating the spectrum, indicating the exchange of angular momentum between auger electron and photoelectron through postcollision interaction effect. 2. Large variations of angular distributions of auger electrons depending on the recapture Rydberg orbital. 3. New insight into the time-dependent dynamics of multistep auger processes including fluorescence, in effect leading to an effective clock mechanism. In addition, new photoelectron correlation set lights were discovered and analyzed in the case of krypton.

Free Research Field

Atomic and molecular physics

Academic Significance and Societal Importance of the Research Achievements

衝突後効果および光電子再捕獲は、量子力学の最も重要な未解決問題の1つである3体クーロン連続状態問題の顕著かつ典型的な例であるといえる。その意味で新たな知見を得る事は物理学の基礎研究として非常に重要である。 また、今回100アト秒オーダーの時間分解測定に相当する結果を自由電子レーザーや超超高検出技術を用いることなく在来技術による実験データから衝突の効果を解析することによって得ることが可能であることが示された。これは、今後の超高速原子分子過程の研究のために有用である。