ポジトロニウム衝撃による内殻イオン化の研究

• Project/Area Number: 14F04027
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 外国
• Research Field: Atomic/Molecular/Quantum electronics
• Research Institution: Tokyo University of Science
• Principal Investigator: 長嶋 泰之 東京理科大学, 理学部, 教授 (60198322)
• Co-Investigator(Kenkyū-buntansha): CHIARI LUCA 東京理科大学, 理学部, 外国人特別研究員 ; CHIARI Luca 東京理科大学, 理学部, 外国人特別研究員
• Project Period (FY): 2014-04-25 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥2,300,000 (Direct Cost: ¥2,300,000); Fiscal Year 2015: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2014: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: 陽電子 / ポジトロニウム / ポジトロニウム負イオン / ビーム / 内殻イオン化 / エネルギー可変ポジトロニウムビーム

Outline of Annual Research Achievements

近年我々は、陽電子1個と電子2個の束縛状態であるポジトロニウム負イオンを生成して電場で加速し、レーザー光を照射して電子を光脱離させることによって、エネルギー可変ポジトロニウムビームを生成することに成功した（Michishio et al., Appl. Phys. Lett. 100 (2012) 254102）。この手法は、電気的に中性であるために加速ができないポジトロニウムのビーム生成法として注目されている。本研究課題は、このようにして生成したエネルギー可変ポジトロニウムビームを用いて、ポジトロニウム衝撃による内殻イオン化の研究を行うものである。
電子などの粒子線を十分加速して原子に衝突させると、内殻の励起が起こって特性X線が放出される。入射粒子が陽電子の場合には、内殻イオン化断面積が電子入射の場合よりも小さくなる（Nagashima et al., Phys. Rev. Lett. 29 (2004) 223201）。これは原子核とのクーロン反発のために陽電子が内殻に近づきにくくなるためで、特に入射エネルギーが閾値付近の場合に顕著である。本課題では、入射粒子が電子と陽電子の束縛状態であるポジトロニウムの場合にはどうなるか調べる研究を行った。
この研究を遂行するためには、径が小さく輝度の高いポジトロニウムビームが必要である。そこで、新たなエネルギー可変ポジトロニウムビーム装置の開発を行った。陽電子溜め込み装置を利用したパルス状陽電子ビームを収束させ、ポジトロニウム負イオン生成に厚さ100nmのタングステン薄膜を用いることによって、大幅な輝度の向上に成功した（Michisio, Chari, et al., 論文執筆中）。
内殻イオン化の測定は目前である。Luca Chiariは、今後は東京理科大学の研究員としてこの研究を継続することになっている。

Research Progress Status

27年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

27年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Experimental and theoretical cross sections for positron scattering from the pentane isomers (2016)
  • Author(s): L. Chiari, A. Zecca, F. Blanco, G. Garcia and M. Brunger
  • Journal Title: Journal of Chemical Physics Volume: 144 Issue: 8
  • DOI: 10.1063/1.4942472
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Development of an energy-tunable positronium beam apparatus using the photodetachment of the positronium negative ion (2015)
  • Author(s): L. Chiari, K. Michishio, N. Oshima, Y. Nagashima
  • Journal Title: Journal of Physics: Conference Series Volume: 635 Issue: 8 Pages: 082003-082003
  • DOI: 10.1088/1742-6596/635/8/082003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Structures in positron-atom and molecule total cross sections (2015)
  • Author(s): A. Zecca, L. Chiari
  • Journal Title: Molecular Physics Volume: 113 Issue: 22 Pages: 3615-3627
  • DOI: 10.1080/00268976.2015.1046524
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Profiles of a positronium beam produced using the photodetachment of positronium negative ions (2015)
  • Author(s): K. Michishio, R. H. Suzuki, K. Wada, I. Mochizuki, T. Hyodo, A. Yagishita, Y. Nagashima
  • Journal Title: Nuclear Instruments and Methods in Physics Research A Volume: 785 Pages: 5-8
  • DOI: 10.1016/j.nima.2015.02.042
  • Peer Reviewed
• [Journal Article] Cross sections for positron and electron collisions with an analog of the purine nucleobases: indole (2015)
  • Author(s): L. Chiari, A. Zecca, F. Blanco, G. Garcia, M. J. Brunger
  • Journal Title: Physical Review A Volume: 91 Issue: 1
  • DOI: 10.1103/physreva.91.012711
  • Peer Reviewed
• [Journal Article] Experiments on positronium negative ions (2014)
  • Author(s): Y. Nagashima
  • Journal Title: Physics Reports Volume: 545 Issue: 3 Pages: 95-123
  • DOI: 10.1016/j.physrep.2014.07.004
  • Peer Reviewed
• [Journal Article] Positron-annihilation-induced ion desorption from TiO2(110) (2014)
  • Author(s): T. Tachibana, T. Hirayama, Y. Nagashima
  • Journal Title: Physical Review B (Rapid Communications) Volume: 89 Issue: 20 Pages: 40-42
  • DOI: 10.1103/physrevb.89.201409
  • Peer Reviewed
• [Journal Article] Low energy positron interactions with uracil - total scattering, positronium formation and differential elastic scattering cross sections (2014)
  • Author(s): E. K. Anderson, R. A. Boadle, J. R. Machacek, L. Chiari, C. Malochekanwa, S. J. Buckman, M. J. Brunger, G. Garcia, F. Blanco, O. Ingolfsson, J. P. Sullivan
  • Journal Title: Journal of Chemical Physics Volume: 141 Issue: 3 Pages: 161-166
  • DOI: 10.1063/1.4887072
  • Peer Reviewed
• [Journal Article] Intermediate-energy differential and integral cross sections for vibrational excitation in α-tetrahydrofurfuryl alcohol (2014)
  • Author(s): H. V. Duque, L. Chiari, D. B. Jones, Z. Pettifer, G. B. da Silva, P. Limao-Vieira, F. Blanco, G. Garcia, R. D. White, M. C. A. Lopes, M. J. Brunger
  • Journal Title: Journal of Chemical Physics Volume: 140 Issue: 21
  • DOI: 10.1063/1.4879779
  • Peer Reviewed
• [Journal Article] Dynamical (e,2e) studies of tetrahydropyran and 1,4-dioxane (2014)
  • Author(s): J. D. Builth-Williams, G. B. da Silva, L. Chiari, D. B. Jones, H. Chaluvadi, D. H. Madison, M. J. Brunger
  • Journal Title: Journal of Chemical Physics Volume: 140 Issue: 21
  • DOI: 10.1063/1.4880204
  • Peer Reviewed
• [Journal Article] Differental cross sections for intermediate-energy electron scattering from α-tetrahydrofurfuryl alcohol: excitation of electronic-states (2014)
  • Author(s): L. Chiari, H. V. Duque, D. B. Jones, P. A. Thorn, Z. Pettifer, G. B. da Silva, P. Limao-Vieira, D. Duflot, M.-J. Hubin-Franskin, J. Delwiche, F. Blanco, G. Garcia, M. C. A. Lopes, K. Ratnavelu, R. D. White, M. J. Brunger
  • Journal Title: Journal of Chemical Physics Volume: 141 Issue: 2
  • DOI: 10.1063/1.4885856
  • Peer Reviewed
• [Journal Article] An experimental and theoretical investigation into the excited electronic states of phenol (2014)
  • Author(s): D. B. Jones, G. B. da Silva, R. F. C. Neves, H. V. Duque, L. Chiari, E. M. de Oliveira, M. C. A. Lopes, R. F. da Costa, M. T. do N. Varella, M. H. F. Bettega, M. A. P. Lima, M. J. Brunger
  • Journal Title: Journal of Chemical Physics Volume: 141 Issue: 7
  • DOI: 10.1063/1.4893116
  • Peer Reviewed
• [Journal Article] Positron scattering from vinyl acetate (2014)
  • Author(s): L. Chiari, A. Zecca, G. Garcia, F. Blanco, M. J. Brunger
  • Journal Title: Journal of Physics B Volume: 47 Issue: 17 Pages: 175202-175202
  • DOI: 10.1088/0953-4075/47/17/175202
  • Peer Reviewed
• [Journal Article] Triply differential (e,2e) studies of phenol (2014)
  • Author(s): G. B. da Silva, R. F. C. Neves, L. Chiari, D. B. Jones, E. Ali, D. H. Madison, C. G. Ning, K. L. Nixon, M. C. A. Lopes, M. J. Brunger
  • Journal Title: Journal of Chemical Physics Volume: 141 Issue: 12
  • DOI: 10.1063/1.4896072
  • Peer Reviewed
• [Journal Article] Recent positron-atom cross section measurements and calculations (2014)
  • Author(s): L. Chiari, A. Zecca
  • Journal Title: The European Physical Journal D Volume: 68 Issue: 10
  • DOI: 10.1140/epjd/e2014-50436-4
  • Peer Reviewed
• [Presentation] Production of a high‐brightness Ps beam by focusing of a trap‐based positron beam (2016)
  • Author(s): L. Chiari, K. Michishio, D. Hoshi, H. Hatano, N. Oshima and Y. Nagashima
  • Organizer: 日本物理学会第71回年会
  • Place of Presentation: 東北学院大学 泉キャンパス
  • Year and Date: 2016-03-19
• [Presentation] Development of an energy-tunable positronium beam apparatus using the photodetachment of the positronium negative ion (2015)
  • Author(s): L. Chiari, K. Michishio, N. Oshima, Y. Nagashima
  • Organizer: XXIX International Conference on Photonic, Electronic and Atomic Collisions
  • Place of Presentation: スペイン、トレド
  • Year and Date: 2015-07-22 – 2015-07-28
• [Presentation] Positron-annihilation induced ion desorption from TiO2 (110) surface (2015)
  • Author(s): L. Chiari, T. Tachibana, M. Nagira, T. Hirayama and Y. Nagashima
  • Organizer: XXIX International Conference on Photonic, Electronic and Atomic Collision
  • Place of Presentation: Toledo, Spain
  • Year and Date: 2015-07-22
  • Int'l Joint Research / Invited
• [Presentation] Cross section measurements for positron and electron scattering from molecules of biological relevance (2015)
  • Author(s): L. Chiari
  • Organizer: XVIII International Workshop on Low-Energy Positron and Positronium Physics
  • Place of Presentation: ポルトガル、リスボン
  • Year and Date: 2015-07-17 – 2015-07-20
  • Invited
• [Presentation] Positron scattering from molecules of biological relevance (2015)
  • Author(s): L. Chiari, S. J. Buckman, J. P. Sullivan
  • Organizer: 15th International Congress of Radiation Research
  • Place of Presentation: 京都
  • Year and Date: 2015-05-25 – 2015-05-29
• [Presentation] Positron surface processes (2014)
  • Author(s): Y. Nagashima
  • Organizer: 11th International Workshop on Positron and Positronium Chemistry
  • Place of Presentation: インド、ゴア
  • Year and Date: 2014-11-09 – 2014-11-14
  • Invited
• [Presentation] Vibrational and electronic excitation of THFA by electron impact (2014)
  • Author(s): L. Chiari, D. B. Jones, H. V. Duque, Z. Pettifer, P. A. Thorn, M. C. A. Lopes, M. J. Brunger
  • Organizer: 11th Asian International Seminar on Atomic and Molecular Physics
  • Place of Presentation: 仙台
  • Year and Date: 2014-10-06 – 2014-10-10
• [Presentation] New development of the Ps- studies (2014)
  • Author(s): Y. Nagashima
  • Organizer: 6th Conference on Elementary Processes in Atomic Systems
  • Place of Presentation: スロバキア、ブラチスラバ
  • Year and Date: 2014-07-09 – 2014-07-12
  • Invited
• [Remarks] 東京理科大学長嶋研究室
  • URL: http://www.rs.kagu.tus.ac.jp/ynagahp/
• [Remarks] 基盤研究(S)ポジトロニウム負イオンの光脱離を利用したポジトロニウムビーム科学の展開
  • URL: http://www.rs.kagu.tus.ac.jp/ynagahp/s/index.html