1991 Fiscal Year Annual Research Report

放射光の波長・偏光・パルス特性を用いた超励起分子の解離ダイナミックス

Research Project

Project/Area Number	03453004
Research Institution	Tokyo Institute of Technology
Principal Investigator	籏野嘉彦東京工業大学, 理学部, 教授 (90016121)
Co-Investigator(Kenkyū-buntansha)	田中健一郎高エネルギー物理学研究所, 放射光実験施設, 助教授 (90106162) 亀田幸成東京工業大学, 理学部, 助手 (90214551) 鵜飼正敏東京工業大学, 理学部, 助手 (80192508) 河内宣之東京工業大学, 理学部, 助教授 (50161873)
Keywords	パルス放射光 / 超励起分子(分子超励起状態) / 中性解離過程 / 水素分子 / 解離原子軌道角運動量分布 / 発光時間分解測定 / 原子・分子反応性衝突
Research Abstract	分子超励起状態の存在とその性質について本研究代表者らは放射線化学反応の実験によりはじめて実証し、その後、電子衝撃実験によりその概要を明らかにしてきた。また最近ではシンクロトロン放射光を用いた実験により分子超励起状態の研究が国際的な競争となりつつある。本研究ではこの様な背景から、放射光の波長特性に加えてパルス特性・偏光特性を組合せて駆使することにより超励起状態のエネルギ-状態ならびに電子状態とその解離過程の詳細の解明を目的とした。平成三年度は、最も簡単な分子である水素分子について、シンクロトロン放射光のパルス特性ならびにそれに追随する高速の同時計数システムを用い、また新たに真空排気系を整備することによって、以下の様な超励起分子の解離等の崩壊ダイナミックスを明らかにすることができた.すなわち、1)高エ研放射光実験施設においてパルス放射光によって光じた超励起水素分子の解離断片原子からのライマンαおよびバルマ-α発光の時間分解測定を行うことにより、生成した励起原子の軌道角運動量分布の測定を世界ではじめて行うことができた。あわせて、生成した励起水素原子と水素分子と反応性衝突という、超励起に引き続く媒質気体分子中の反応素過程についても新しい手法の開発により研究を行った。なお同位体効果についても間もなく実験予定である。2)窒素、酸素、一酸化炭素などの基本的かつ重要な分子について、シンクロトロン放射光を用いて超励起状態を生成させその解離過程を観測することによる、従来とは全く異なる分光法を開発し種々の超励起状態をはじめて観測することに成功した。3)さらに、超励起状態のエネルギ-状態、電子状態に特徴的な解離過程を研究するため、光吸収・光電離・光解離の各過程の全断面積解離過程を研究するため、光吸収・光電離・光解離の各過程の全断面積絶対値測定をハロゲン化メタン、ハロゲン化ケイ素等種々の分子について行った。以上、ほぼ計画通り遅滞無く研究を遂行することができた。

Research Products
(17 results)

All Other

All Publications (17 results)

[Publications] K.Kameta: "Absolute measurements of photoabsrption cross sections,photoionization cross sections,and photoionization quantum yields of silane in the 13ー40 eV region." The Journal of Chemical Physics.95. 1456-1460 (1991)
[Publications] M.Ukai: "Ionizing and nonionizing decays of superexcited acetylene molecules in the extremeーultraviolet region." The Journal of Chemical Physics.95. 4142-4153 (1991)
[Publications] K.Kameta: "Absolute measurements of photoabsorption and photoionization cross sections of disilane in the 13ー40 eV region." The Journal of Chemical Physics.95. 6188-6189 (1991)
[Publications] M.Ukai: "Optical threshold excitation functions of Xe 5s,5p photoionization satellites near the 5s^<-1> Cooper minimum." The Physical Review.A45. R15-R18 (1992)
[Publications] K.Kameta: "Photoabsorption,photoionization,and neutral dissociation cross sections of dimethyl ether and ethyl methyl ether in the extremeーultraviolet range." The Journal of Chemical Physics. 96. (1992)
[Publications] N.Kouchi: "Angular momentum population of excited H atoms produced through photodissociation of H_2." Chemical Physics Letters. (1992)
[Publications] M.Ukai: "Fluorescence excitation spectra excited by photodissociation and photoionization of CO_2." “Synchrotron Radiation and Dynamic Phenomena"Proceedings of the 48th International Meeting of Physical Chmistry,ed.C.Troyanowsky,(American Institute of Physics,New York). (1992)
[Publications] M.Ukai: "The role of shape resonance in ionizing nonionizing decays of superexcited acetylene molecules in the EUV region." “Synchrotron Radiation and Dynamic Phenomena",Proceedings of the 48th International Meeting of Physical Chemistry,ed.C.Troyanowsky,(AIP,New York). (1992)
[Publications] K.Kameta: "Absolute measurements of photoabsorption,photoionization,and photoーdissociation cross sections of SiH_4 and Si_2H_6 in the 13ー22 eV region." “Synchrotron Radiation and Dynamic Phenomena",Proceedings of the 48th International Meeting of Physical Chemistry,ed.C.Troyanowsky,(AIP,New York). (1992)
[Publications] M.Ukai: "State selective ionization of O_2 in a framework of van der Waals molecule." “Synchrotron Radiation and Dynamic Phenomena",Proceedings of the 48th International Meeting of Physical Chemistry,ed.C.Troyanowsky,(AIP,New York). (1992)
[Publications] N.Terazawa: "Angular momentum population of H(3 )produced through photodissociation of H_2." Photon Factroy Activity Report 1991.(KEK). ♯9. (1992)
[Publications] M.Ukaie: "Extreme ultraviolet photodissocaition of free CO molecule." Photon Factory Activity Report 1991,(KEK). ♯9. (1992)
[Publications] M.Ukai: "Optical threshold excitation functions of Xe 5s,5p photoionization satellites near the 5s^<-1> Cooper minimum." Photon Factory Activity Report 1991,(KEK). #9. (1992)
[Publications] M.Ukai: "Partial photodissociation cross sections of O_2 molecules as probed by vacuum ultrviolet fluorescence." Photon Factory Activity Report 1991,(KEK). #9. (1992)
[Publications] M.Ukai: "Autoionizingーresonance enhanced preferntial photodissociation of CO_2 in superexcited states." The Journal of Chemical Physics.
[Publications] M.Ukai: "Extreme ultra violet photodissociation of O_2 via the free(c^4Σ^+_u)3sσ state as probed by dispersed vacuum ultrviolet fluorescence." Chemical Physics Letters.
[Publications] M.Ukai: "Neutral decay of doubleーholed doublyーexcited resonances of N_2." Physical Review Letters.

1991 Fiscal Year Annual Research Report

放射光の波長・偏光・パルス特性を用いた超励起分子の解離ダイナミックス

Principal Investigator

籏野 嘉彦 東京工業大学, 理学部, 教授 (90016121)

Research Products

[Publications] K.Kameta: "Absolute measurements of photoabsrption cross sections,photoionization cross sections,and photoionization quantum yields of silane in the 13ー40 eV region." The Journal of Chemical Physics.95. 1456-1460 (1991)

[Publications] M.Ukai: "Ionizing and nonionizing decays of superexcited acetylene molecules in the extremeーultraviolet region." The Journal of Chemical Physics.95. 4142-4153 (1991)

[Publications] K.Kameta: "Absolute measurements of photoabsorption and photoionization cross sections of disilane in the 13ー40 eV region." The Journal of Chemical Physics.95. 6188-6189 (1991)

[Publications] M.Ukai: "Optical threshold excitation functions of Xe 5s,5p photoionization satellites near the 5s^<-1> Cooper minimum." The Physical Review.A45. R15-R18 (1992)

[Publications] K.Kameta: "Photoabsorption,photoionization,and neutral dissociation cross sections of dimethyl ether and ethyl methyl ether in the extremeーultraviolet range." The Journal of Chemical Physics. 96. (1992)

[Publications] N.Kouchi: "Angular momentum population of excited H atoms produced through photodissociation of H_2." Chemical Physics Letters. (1992)

[Publications] M.Ukai: "Fluorescence excitation spectra excited by photodissociation and photoionization of CO_2." “Synchrotron Radiation and Dynamic Phenomena"Proceedings of the 48th International Meeting of Physical Chmistry,ed.C.Troyanowsky,(American Institute of Physics,New York). (1992)

[Publications] M.Ukai: "The role of shape resonance in ionizing nonionizing decays of superexcited acetylene molecules in the EUV region." “Synchrotron Radiation and Dynamic Phenomena",Proceedings of the 48th International Meeting of Physical Chemistry,ed.C.Troyanowsky,(AIP,New York). (1992)

[Publications] M.Ukai: "State selective ionization of O_2 in a framework of van der Waals molecule." “Synchrotron Radiation and Dynamic Phenomena",Proceedings of the 48th International Meeting of Physical Chemistry,ed.C.Troyanowsky,(AIP,New York). (1992)

[Publications] N.Terazawa: "Angular momentum population of H(3 )produced through photodissociation of H_2." Photon Factroy Activity Report 1991.(KEK). ♯9. (1992)

[Publications] M.Ukaie: "Extreme ultraviolet photodissocaition of free CO molecule." Photon Factory Activity Report 1991,(KEK). ♯9. (1992)

[Publications] M.Ukai: "Optical threshold excitation functions of Xe 5s,5p photoionization satellites near the 5s^<-1> Cooper minimum." Photon Factory Activity Report 1991,(KEK). #9. (1992)

[Publications] M.Ukai: "Partial photodissociation cross sections of O_2 molecules as probed by vacuum ultrviolet fluorescence." Photon Factory Activity Report 1991,(KEK). #9. (1992)

[Publications] M.Ukai: "Autoionizingーresonance enhanced preferntial photodissociation of CO_2 in superexcited states." The Journal of Chemical Physics.

[Publications] M.Ukai: "Extreme ultra violet photodissociation of O_2 via the free(c^4Σ^+_u)3sσ state as probed by dispersed vacuum ultrviolet fluorescence." Chemical Physics Letters.

[Publications] M.Ukai: "Neutral decay of doubleーholed doublyーexcited resonances of N_2." Physical Review Letters.

籏野嘉彦東京工業大学, 理学部, 教授 (90016121)