Detection of atoms with ultraviolet emission induced by two-photon excitation with ultraviolet light

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05374
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Hiroshima University
• Principal Investigator: Yamasaki Katsuyoshi 広島大学, 先進理工系科学研究科(理), 教授 (90210385)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: レーザ分光法 / レーザ誘起蛍光法 / 2光子励起 / 真空紫外発光 / 電子消光

Outline of Final Research Achievements

We have succeeded in developing a new method for detecting oxygen, sulfur, chlorine, and bromine atoms by two-photon UV excitation and vacuum UV emission. For oxygen and sulfur atoms, the rate coefficients for overall and state-selective quenching of the two-photon excitation level by collisions with He and N2 were determined. For chlorine and bromine atoms, we tried to detect 25 allowed transitions and succeeded in detecting 18 chlorine and 20 bromine transitions, respectively. Four of the undetectable transitions were common to the two atoms and were all in the quartet state, indicating that the spin forbiddance is not completely broken even for the halogen atoms with large spin-orbit interactions.

Free Research Field

反応物理化学

Academic Significance and Societal Importance of the Research Achievements

酸素原子，塩素原子，臭素原子について，過去に例がない2光子励起真空紫外発光検出法を確立し，赤外発光を検出する従来法の検出限界濃度10^13 cm-3よりも約2桁低い濃度(10^11 cm-3)の検出を目標どおり実現できたことは，燃焼化学，大気化学，プラズマ化学の研究において精緻な観測や診断が可能になる意味で工学面での学術的成果である。また，2光子励起準位の消光過程について総括速度定数だけでなく，特定の状態間の消光過程の分岐比を決定する方法論を確立し測定に成功したことは理学面での大きな学術的成果である。