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Kenji Motohashi

Faculty
Department of Biomedical Engineering
Bio-Nano Electronics Research Center
Research Institute of Industrial Technology
Course of Biomedical Engineering
PositionProfessor
Mail
HomepageURL
Birthday
Last Updated :2020/07/09

Researcher Profile and Settings

Education

  •  - 1991 , Tokyo University of Agriculture and Technology
  •  - 1991 , Tokyo University of Agriculture and Technology, Graduate School, Division of Engineering
  •  - 1989 , Tokyo University of Agriculture and Technology, Faculty of Engineering
  •  - 1989 , Tokyo University of Agriculture and Technology, Faculty of Engineering

Association Memberships

  • THE SOCIETY FOR ATOMIC COLLISION RESEANCH
  • The Japan Society of Vacuum and Surface Science
  • Japanese Society of Atomic Collisions
  • The Surface Science Society of Japan
  • The Japan Society of Medical Physics
  • The Japan Society of Applied Physics
  • The Physical Society of Japan

Academic & Professional Experience

  •   2015 04  - 現在, Toyo University, Faculty of Science and Engineering, Department of Biomedical Engineering
  •   2009 04  - 2015 03 , Toyo University, Faculty of Science and Engineering
  •   2007 10  - 2014 03 , RIKEN
  •   2007 04  - 2009 03 , Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology
  •   1993 04  - 2007 03 , Tokyo University of Agriculture and Technology, Faculty of Engineering

Research Activities

Research Areas

  • Energy, Quantum beam science
  • Energy, Basic plasma science
  • Nanotechnology/Materials, Thin-film surfaces and interfaces
  • Natural sciences, Semiconductors, optical and atomic physics

Research Interests

    Cluster, Ionizing Radiation, Plasma, and Molecules, Atoms, Electrons, Highly-charged Ions, Surface Science, Atomic Physics

Published Papers

  • Guiding a 7.5 keV Ar3+ ion beam using a cylindrical glass channel, Kenji Motohashi, Shu Ishii, Japanese Journal of Applied Physics, Japanese Journal of Applied Physics, 59, (5) 056002-1 - 056002-7, 04 28 , Refereed
  • KINETIC ENERGY DISTRIBUTION OF SLOW MULTIPLY CHARGED ARGON IONS TRANSMITTED THROUGH A CYLINDRICAL GLASS CHANNEL, Kenji Motohashi, ION-SURFACE INTERACTIONS, ION-SURFACE INTERACTIONS, 1, 167 - 169, 08
  • A homework of time period measurement of physical pendulum to enhance the understanding of the concept of moment of inertia, Kenji Motohashi, Journal of Education Career Center, Journal of Education Career Center, 1, (1) 27 - 32, 03 , Refereed
  • Synthesis of Iron-Fullerene Complexes by Scattering of C60 Ions on Ferrocenyl-Undecanethiol SAM Surfaces, Kenji Motohashi, Tomoki Tachikawa, Takashi Uchida, Kensei Kawamura, e-J. Surf. Sci. Nanotech., e-J. Surf. Sci. Nanotech., 16, 127 - 131, 05 , Refereed
    DOI
  • Guiding of 4MeV C+ and C4+ ion beams using cylindrical glass channel, Kenji Motohashi, Nobumasa Miyawaki, Yuichi Saitoh, Kazumasa Narumi, Shiro Matoba, JAPANESE JOURNAL OF APPLIED PHYSICS, JAPANESE JOURNAL OF APPLIED PHYSICS, 56, (4) 046301-1 - 046301-6, 04 , Refereed
    DOI
  • Level-energy-dependent mean velocities of excited tungsten atoms sputtered by krypton-ion bombardment, Keisuke Nogami, Yasuhiro Sakai, Shota Mineta, Daiji Kato, Izumi Murakami, Hiroyuki A. Sakaue, Takahiro Kenmotsu, Kenji Furuya, Kenji Motohashi, JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A, JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A, 33, (6) 061602-1 - 061602-7, 11 , Refereed
    DOI
  • Highly charged ion scattering on single-crystalline (0001) and (000(1)over-bar) zinc-oxide surfaces, Kenji Motohashi, Tokihiro Ikeda, Takao M. Kojima, Yuki Suzuki, VACUUM, VACUUM, 104, 22 - 28, 06 , Refereed
    DOI
  • Alignment in magnetic sub-level populations of excited atomic hydrogen formed by single-electron capture from metal surfaces, Daiji Kato, Hiroyuki A. Sakaue, Takahiro Kenmotsu, Yasuhiro Sakai, Kenji Motohashi, XXVIII INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS (ICPEAC), XXVIII INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS (ICPEAC), 488, (13) 132012-1 - 132012-1, Refereed
    DOI
  • Mean velocity of 5d(5)6p excited tungsten atoms sputtered by Kr+ ion bombardment, Kenji Motohashi, Keisuke Nogami, Yasuhiro Sakai, Hiroyuki A. Sakaue, Daiji Kato, Takahiro Kenmotsu, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 283, 59 - 62, 07 , Refereed
    DOI
  • MOTOHASHI Kenji, NOGAMI Keisuke, SAKAI Yasuhiro, SAKAUE Hiroyuki, KATO Daiji, KENMOTSU Takahiro, 283, 59 - 62, 04 , Refereed
    DOI
  • Optical emission spectroscopy by Ar3+ ion sputtering of Ti surface under O-2 environment, Kenji Motohashi, Yuichi Saitoh, Shin-iti Kitazawa, APPLIED SURFACE SCIENCE, APPLIED SURFACE SCIENCE, 257, (13) 5789 - 5792, 04 , Refereed
    DOI
  • Selective Sputtering of Impurity Hydrogen Atoms from a GaN(0001) Surface by Slow Multicharged Ion Impact, Kenji Motohashi, APPLIED PHYSICS EXPRESS, APPLIED PHYSICS EXPRESS, 3, (12) 126301-1 - 126301-3, Refereed
    DOI
  • Fragmentation and desorption in low-energy highly charged ion collisions with molecules and surfaces, K. Motohashi, 14TH INTERNATIONAL CONFERENCE ON THE PHYSICS OF HIGHLY CHARGED IONS (HCI 2008), 14TH INTERNATIONAL CONFERENCE ON THE PHYSICS OF HIGHLY CHARGED IONS (HCI 2008), 163, 012005-1 - 012005-6, Refereed, Invited
    DOI
  • Desorption and Sputtering on Solid Surfaces by Low-Energy Multicharged Ions, K. Motohashi, XXVI INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS, XXVI INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS, 194, 012061-1 - 012061-8, Refereed
    DOI
  • Secondary-ion emission from GaN(0001) and dodecanethiol/Au(111) surfaces irradiated with Arq+ (q=4-8), K. Motohashi, M. Flores, Y. Kanai, 14TH INTERNATIONAL CONFERENCE ON THE PHYSICS OF HIGHLY CHARGED IONS (HCI 2008), 14TH INTERNATIONAL CONFERENCE ON THE PHYSICS OF HIGHLY CHARGED IONS (HCI 2008), 163, 012080-1 - 012080-4, Refereed
    DOI
  • Analyses of GaN (0001) and (0 0 0 (1)over-bar) surfaces by highly-charged ions, K. Motohashi, K. Hosoya, M. Imano, S. Tsurubuchi, A. Koukitu, SURFACE SCIENCE, SURFACE SCIENCE, 601, (22) 5304 - 5308, 11 , Refereed
    DOI
  • Proton sputtering from polycrystalline Al surface interacting with highly charged ions at grazing incidence angle, Kenji Motohashi, Seiji Tsurubuchi, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 264, (1) 15 - 22, 11 , Refereed
    DOI
  • Emission cross sections in low-energy collisions between He+, Ne+ ions and CF4 molecule, K Motohashi, T Takahashi, N Takahashi, S Tsurubuchi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 38, (18) 3339 - 3348, 09 , Refereed
    DOI
  • Momentum-imaging spectroscopy of secondary ions from GaN and SiC surfaces collided with highly charged ions at grazing angle, K Motohashi, S Tsurubuchi, A Koukitu, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 232, 254 - 260, 05 , Refereed
    DOI
  • Momentum distribution of fragment ions produced in collisions of Arq+ with CH4 and CF4, K Motohashi, S Tsurubuchi, CORRELATIONS, POLARIZATION, AND IONIZATION IN ATOMIC SYSTEMS, CORRELATIONS, POLARIZATION, AND IONIZATION IN ATOMIC SYSTEMS, 604, 291 - 296, Refereed
  • Spectroscopic studies at the Tokyo electron beam ion trap, S. Ohtani, F. J. Currell, T. Fukami, T. Hirayama, D. Kato, H. Kuramoto, k. Motohashi, N. Nakamura, E. Nojikawa, K. Okazaki, M. Sakurai, H. Shimizu, E. J. Sokell, XVI International Conference on Atomic Physics, Windsor, Canada Aug.6, XVI International Conference on Atomic Physics, Windsor, Canada Aug.6, 08
  • Some Results from the Tokyo-EBIT in 1997-1998, S. Ohtani, J.Asada, F.J. Currell, A.Y.Faenove, T.Fukami, T.Hirayama, D.Kato, T.Kinugawa, H.Kuramoto, K.Motohashi, N.Nakamura, E.Nojikawa, K.Okazaki, T.A.Pikus, Atomic collision research in Japan, 24, Atomic collision research in Japan, 24, 138 - 140
  • Tokyo-EBITを用いた多価イオンの分光学的研究(]G0002[), 深見恒光, 岡崎清比古, 加藤太治, 中村信行, 本橋健次, 鶴淵誠二, 大谷俊介, 原子衝突研究会第23回研究会講演概要集, 原子衝突研究会第23回研究会講演概要集, 120 - 121
  • Detector systems for use with an Electron Beam Ion Trap, FJ Currell, J Asada, T Fukami, H Hirayama, N Nakamura, K Motohashi, E Nojikawa, K Okazaki, S Ohtani, M Sakurai, H Shiraishi, S Tsurubuchi, H Watanabe, PHYSICA SCRIPTA, PHYSICA SCRIPTA, T73, 371 - 372, Refereed
    DOI
  • Optical emission spectroscopy of sputtered Al atoms from Al and Al2O3 surfaces interacted with Arq+ (q = 1-9), K Motohashi, S Tsurubuchi, H Shimizu, K Mochiji, H Tanuma, N Kobayashi, PHYSICA SCRIPTA, PHYSICA SCRIPTA, T73, 329 - 331, Refereed
  • Extraction of trapped ions from the Tokyo Electron Beam Ion Trap, K Motohashi, J Asada, FJ Currell, T Fukami, T Hirayama, K Mochiji, N Nakamura, E Nojikawa, K Okazaki, S Ohtani, M Sakurai, H Shiraishi, S Tsurubuchi, H Watanabe, PHYSICA SCRIPTA, PHYSICA SCRIPTA, T73, 368 - 370, Refereed
    DOI
  • Dissociative excitation of CH4 by electron impact: Emission cross sections for the fragment species, K Motohashi, H Soshi, M Ukai, CHEMICAL PHYSICS, CHEMICAL PHYSICS, 213, (1-3) 369 - 384, 12 , Refereed
    DOI
  • EXCITATION OF THE 3S3P(6) STATE OF AR+ BY ELECTRON-IMPACT, S TSURUBUCHI, T MIYAZAKI, K MOTOHASHI, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 63, (11) 3996 - 3999, 11 , Refereed
    DOI
  • DISSOCIATIVE EXCITATION OF SIH4 BY ELECTRON-IMPACT - EMISSION CROSS-SECTIONS FOR FRAGMENT SPECIES, S TSURUBUCHI, K MOTOHASHI, S MATSUOKA, T ARIKAWA, CHEMICAL PHYSICS, CHEMICAL PHYSICS, 161, (3) 493 - 500, 04 , Refereed
    DOI
  • DISSOCIATIVE EXCITATION OF SIH4 BY ELECTRON-IMPACT - EMISSION CROSS-SECTIONS FOR THE HYDROGEN LYMAN SERIES, S TSURUBUCHI, K MOTOHASHI, S MATSUOKA, T ARIKAWA, CHEMICAL PHYSICS, CHEMICAL PHYSICS, 155, (3) 401 - 406, 09 , Refereed
    DOI

Misc

  • Guiding of slow multiply charged C60 and Ar ion beams using cylindrical glass channel, Kenji Motohashi, Achievements in the bio-nano innovation programme, 2016-2018,   2019 04 , 招待有り, Development of nano robotics: Application of nano robots to biomedical and environmental studies
  • Flux Enhancement of Carbon Ion Beams Guided by Cylindrical Glass Channel, K. Motohashi, N. Miyawaki, K. Narumi, Y. Saitoh, QST Takasaki Annual Report 2017, QST-M-16,   2019 03 , 査読有り, 招待有り, We have been developing the cylindrical glass channel (CGC), which comprises a cylindrically concave glass lens and a cylindrically convex glass lens facing each other with a gap of 1.2 mm. The transmission probability and the kinetic energy of outgoing ions from the CGC suggested that 4-MeV carbon ions guided by the channel were converged. In the present study, to confirm this ion beam convergence experimentally, we attempted to measure the flux of the outgoing ion beam.
  • Transmission Properties of a 6-MeV Fullerene Ion Beam through a Wedge-shaped Glass Channel, Kenji Motohashi, Nobumasa Miyawaki, Yuichi Saitoh, Kazumasa Narumi, QST Takasaki Annual Report 2016, QST-M-8,   2018 03 , 査読有り
  • フェロセンで覆われたイオン流路にC60イオンを入射した際の出射粒子の質量分析, 立川知樹, 内田貴司, 本橋健次, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 64th,   2017 03 01
  • Kinetic Energy Distributions of 4-MeV C+ and C4+ Ion Beams Guided by a Cylindrical Glass Channel, Kenji Motohashi, Yuichi Saitoh, Nobumasa Miyawaki, Kazumasa Narumi, QST Takasaki Annual Report 2015, QST-M-2,   2017 03 , 査読有り, 招待有り, The influence of initial charge states of 4-MeV ion beams on guiding effects were investigated by comparing C4+ with C+. The results obtained in this study is essentially means that the guiding effect was indeed in play under this investigative scenario; moreover, the absence of ion beam deflection was likewise ensured because no transmissions beyond the range of the primary ion angle were detected.
  • Kinetic Energy Distribution of 4-MeV-C4+ Ions, Kenji Motohashi, Yuichi Saito, Nobumasa Miyawaki, Shiro Matoba, JAEA Review, 2015-022,   2016 02 , 査読有り, 招待有り
  • 21pBE-5 Intensity and polarization measurements of Hα radiation by H^+ impact on W surface, Sakaue H. A, Kato D, Murakami I, Mineta S, Lee G, Sakai Y, Furuya K, Kenmosu T, Motohashi K, Meeting Abstracts of the Physical Society of Japan, 71,   2016
  • 17pAA-5 Intensity and polarization measurements of Hα radiation by H^+ impact on W surface, Sakaue H. A, Miyamoto T, Sakurai M, Motohashi K, Kato D, Murakami I, Mineta S, Lee G, Sakai Y, Furuya K, Kenmosu T, Sasaki K, Meeting Abstracts of the Physical Society of Japan, 70,   2015
  • 29aEC-5 Optical emission spectroscopy of excitation with spattering or back scattering atom on tungsten surface under ion irradiation, Nogami K, Kato D, Kenmotsu T, Sakai Y, Sakaue H. A, Furuya K, Motohash K, Meeting Abstracts of the Physical Society of Japan, 68,   2013
  • Optical emission spectroscopy of excitation with spattering or back scattering atom on tungsten surface under ion irradiation, Sakai Y, Kaga S, Kato D, Kenmotsu T, Sakaue H. A, Furuya K, Motohash K, Meeting Abstracts of the Physical Society of Japan, 68,   2013
  • 25pYG-8 Optical emission spectroscopy of sputtering atoms on tungsten surfaces under ion irradiation II, Nogami K, Kato D, Kenmotsu T, Sakai Y, Sakaue H. A, Furuya K, Motohashi K, Meeting Abstracts of the Physical Society of Japan, 67,   2012
  • 22aEE-7 Optical emission spectroscopy of excited particles desorbing from an immobilized protein surface under irradiation of electron beam, Motohashi K, Aoyagi S, Meeting abstracts of the Physical Society of Japan, 66,   2011 08 24
  • Surface Chemical Analysis Using Multiply Charged Ions, Kenji Motohashi, e-J. Surf. Sci. Nanotech., 7,   2009
    DOI
  • Proton sputtering from polycrystalline Al surface interacting with highly charged ions at grazing incidence angle, Kenji Motohashi, Seiji Tsurubuchi, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 264, (1) 15 - 22,   2007 11 , Sputtering processes of protons from a polycrystalline At surface interacting with Arq+ (q = 3-14) ions at a grazing incidence angle (similar to 0.5 degrees) were investigated. The intensity of protons (I-H) detected in coincidence with scattered Ar atoms was measured as a function of q. I-H saturated at q >= 10, although it increased rapidly with q at 3 <= q <= 8. The angular distribution of protons with low kinetic energy (<= 2 eV) began to deviate from the cosine distribution and assumed a rather flat equidistribution as q increased. To analyze the sputtering processes of protons at the grazing incidence angle, a modified model of the "above-surface potential sputtering model" was proposed by considering image acceleration of projectile ions. (C) 2007 Elsevier B.V. All rights reserved.
    DOI
  • Analyses of GaN (0001) and (0 0 0 (1)over-bar) surfaces by highly-charged ions, K. Motohashi, K. Hosoya, M. Imano, S. Tsurubuchi, A. Koukitu, SURFACE SCIENCE, 601, (22) 5304 - 5308,   2007 11 , Secondary-ion mass spectroscopic studies for wurtzite GaN (0 0 0 1) and (0 0 0 (1) over bar) surfaces grown by hydride-vapor phase epitaxy were carried out using highly-charged ions. The secondary ions of impurities adsorbed on the surfaces, such as proton, H-2(+), and CmHn+ (m = 1- 6 and n = 0-13), were preferentially desorbed by the grazing incidence of Arq+ (q = 6-11). A spectrum peak of Ga+ was observed only in the (0 0 0 1) surface, whereas an enhancement of the peak intensity of N+ was observed in the (0 0 0 (1) over bar) surfaces. The time difference between the two peaks was also observed in the time-of-flight spectra of protons emitted from the (0 0 0 1) and (0 0 0 (1) over bar) surfaces. It was concluded that these differences were due to the surface polarity of GaN. (c) 2007 Elsevier B.V. All rights reserved.
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  • Secondary-Ion Emission in Grazing Collisions between Highly Charged Ions and Surfaces, Kenji Motohashi, Seiji Tsurubuchi, Akinori Koukitu, J. Phys.: Conference Series, 80,   2007
    DOI
  • HIghly Charged Ions - Atoms, Molecules and Solid Surfaces, Kenji Motohashi, Journal of Plasma and Fusion Research, 83, (8) 665 - 670,   2007
  • 多価イオン‐固体表面衝突における二次イオンの放出角測定, 本橋健次, 今野深貴, 鶴淵誠二, 纐纈明伯, 原子衝突研究協会研究会講演概要集, 31st,   2006 08 10
  • 25pWD-10 Secondary-ion emission in collisions between multiply-charged ions and solid surfaces characterized by energy loss of the incident ions, Motohashi K, Imano M, Tsurubuchi S, Koukitu A, Meeting Abstracts of the Physical Society of Japan, 61,   2006
  • High-efficiency and low-damage analysis of solid surfaces by use of highly-charged ions, K. Motohashi, S. tsurubuchi, A. Koukitu, The 21st Century COE program on "Future Nano-Material" News Letter, 4,   2006
  • Report on Cross Section Data Compilation for Electron and Ion Collisions with Molecules of Hydrogen Isotopes, Nitrogen, Oxygen, Hydrocarbons, Water and Carbon Oxide, M. Kimura, A. Igarashi, M. Imai, Y. Itikawa, M. Kitajima, T. Kusakabe, K. Moribayashi, T. Morishita, K. Motohashi, L. Pichl, R. Suzuki, D. Kato, I. Murakami, T. kato, M. Kato, National Institute for Fusion Science Research Report, NIFS-DATA-98,   2006
  • Emission cross sections in low-energy collisions between He+, Ne+ ions and CF4 molecule, K Motohashi, T Takahashi, N Takahashi, S Tsurubuchi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 38, (18) 3339 - 3348,   2005 09 , Emission cross sections (Q(em),) of CF4+((C) over tilde-(A) over tilde, (C) over tilde-(X) over tilde; 200-500 nm), CF4+((D) over tilde-(C) over tilde, 350-440 nm), F(3p D-4 degrees(7/2)-3s P-4(5/2); 685.6 nm), He(3d D-3-2p P-3(o); 587.6 nm), and Ne(3p (2)[5/2]-3S (2)[3/2]; 640.2 nm) produced in charge-exchange collisions between He+ and Ne+ and CF4 molecule were measured in the energy range below 5000 eV down to 1 eV (E-Lab). Emission cross sections of F(3s P-2-2p(5) P-2(o); 95.5 nm) and F(3s P-4-2p(5) P-2(o); 97.5 nm) were also measured in He++CF4. No emission peaks were observed in the spectrum of Ar++CF4 (E-Lab = 2000 eV) in the wavelength range of 200-800 nm. The emission cross section of CF4(C-A, C-X; 200-500 nm) observed in Ne++CF4 decreased with increasing the energy with a relation of Qem alpha E-CM(-1/2) up to 60 eV, whereas it increased with increasing the energy above 100 eV. This result agreed well with one of Sasaki et al [1]. It was concluded that such dependence below 60 eV originated from an orbiting resonance into Ne+CF4+((C) over tilde T-2(2) ) channel. Emission cross sections of F, He and Ne rapidly increased with increasing the energy from the near thresholds.
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  • Momentum-imaging spectroscopy of secondary ions from GaN and SiC surfaces collided with highly charged ions at grazing angle, K Motohashi, S Tsurubuchi, A Koukitu, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 232, (1-4) 254 - 260,   2005 05 , Three-dimensional momentum of sputtered ions were measured in coincidence with scattered Ar atoms in collisions between Arq+ (q = 3, 8, 11, and 14) and 6H-SiC and GaN surfaces at grazing-incidence angle (< 0.50). H+, H-2(+), Si+ and Ga+ ions were observed in time-of-flight-mass spectra. Sputtering yields of H+ and H-2(+) increased with increasing charge states of incident ions in proportion to q(4). The momenta of these secondary ions emitted from the surfaces were intensively distributed to the direction of surface normal in spite of the grazing collisions. Almost no significant change among different q was found in the kinetic energy distributions of these secondary ions. (c) 2005 Elsevier B.V. All rights reserved.
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  • A new method for analysis and modification of wide-gap semiconductor surfaces by using highly-charged ions, K. Motohashi, S. Tsurubuchi, A. Koukitu, The 21st Century COE program on "Future Nano-Material" News Letter, 3,   2005
  • 15pTE-6 Secondary-ion emission from GaN surfaces interacted with highly-charged ions, Motohashi Kenji, Tsurubuchi Seiji, Koukitu Akinori, Meeting Abstracts of the Physical Society of Japan, 59,   2004
  • 29pXN-13 Secondary-ion emission from a compound-semiconductor surface interacted with highly-charged ions with low energies, Motohashi K, Tsurubuchi S, Koukitu A, Meeting Abstracts of the Physical Society of Japan, 59,   2004
  • A fundamental study on the sputtering processes of wide-gap semiconductors by highly-charged-ion impact, Kenji Motohashi, Seiji Tsurubuchi,   2004
  • A fundamental study on the sputtering processes of wide-gap semiconductors by highly-charged-ion impact, Kenji Motohashi, Seiji Tsurubuchi, News Letter: The 21st Century COE (Center of Excellence) program on "Future Nano-Material",   2004
  • Fundamental Study on Atomic Structure of Compound Semiconductor Surfaces, Seiji Tsurubuchi, Kenji Motohashi, Akinori Koukitu, News Letter: The 21st Century COE (center of Excellence) program on "Future Nano-Material", 2,   2004
  • Fundamental study on atomic structure of compound semiconductor surfaces by highly charged ions, Seiji Tsurubuchi, Kenji Motohashi, Akinori Koukitu,   2004
  • Energy-gain-characterized 3D momentum-imaging spectroscopy of N+ ions produced in Arq+ (q=3,8,9,11 and 12) collisions with N-2 molecules, S Tsurubuchi, K Motohashi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 36, (18) 3847 - 3863,   2003 09 , The 3D momenta of N+ fragment ions were measured in coincidence with energy-gain-characterized Ar(q-1)+* in electron transfer collisions between Arq+ (q = 3, 8, 9, 11 and 12) and N-2 molecules at 8.0 keV (lab.). The projectile ions scattered within very small angles (less than or equal to0.017degrees) were selectively detected to carry out measurements under the condition that the energy gain became approximately equal to the heat of reaction for the collision system. Main components due to single-electron transfer as well as subcomponents due to transfer ionization of double-, triple- and quadruple-electron transfer processes were observed in the energy gain spectra. It was found that the predissociation from N-2(+) (C (2)Sigma(u)(+) : upsilon' greater than or equal to 3) and direct fragmentations from N-2(2+*) ((1)Pi(u), (1)Delta(g) and (3)Delta(u)) play important roles in the dissociation processes. The electronic state of both the projectile ion and N-2 molecule producedjust after the electron transfer processes were assigned by measuring the heat of reaction.
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  • 3D-momentum-imaging spectroscopy of fragment ions produced in electron transfer collisions between energy-gain selected Arq+ (q=3, 8, 9, 11 and 12) and CF4 molecules, K Motohashi, S Tsurubuchi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 36, (9) 1811 - 1833,   2003 05 , The energy gain of Ar(q-1)+* scattered at small angle (< 0.29 mrad) and three-dimensional momenta of fragment ions were measured in coincidence in electron transfer collisions between Arq+ (q = 3, 8, 9, 11 and 12) and CF4. The experiments were carried out under the condition that the energy gain becomes approximately equal to the heat of reaction for the intermediate collision system produced just after the electron transfer process. Main components due to single-electron transfer as well as sub-components due to transfer ionization of double-, triple- and quadruple-electron transfer processes were clearly observed in the energy-gain spectra. The position and height of the energy-gain spectra were in good agreement with the theoretical ones calculated by the classical over-the-barrier model. The shapes of time-of-flight mass spectra of fragment ions were drastically changed between single- and double-electron transfer (transfer ionization). 3D momenta of F+, CF+, CF2+, CF32+ CF22+ and CF32+. were measured with a new spectroscopic device, as well as the energy gain of Ar(q-1)+*. Both electronic states of Ar(q-n)+* and CF4n+* (n = 1 and 2) produced just after the electron transfer were assigned experimentally by taking into account the released kinetic energy which was converted from the 3D momenta of fragment ions and the heat of reaction.
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  • 3D-momentum images of sputtered ions from a SiC surface interacted with highly-charged Ar ions, K. Motohashi, K. Hosoya, M. Tanaka, S. Tsurubuchi, Atomic Collision Research in Japan -Progress report-, 29,   2003
  • Momentum-imaging spectroscopy of fragment ions in excitation of molecules by electron impact, Y. Yamaguchi, Y. Iriki, K. Motohashi, S. Tsurubuchi, Atomic Collision Research in Japan -Progress Report-, 29,   2003
  • AMDIS and CHART update (I), I. Murakami, T. Kato, A. Igarashi, M. Imai, Y. Itikawa, D. Kato, M. Kimura, T. Kusakabe, K. Moribayashi, T. Morishita, K. Motohashi, L. Pichl, National Institute for Fusion Science・RESEARCH REPORT NIFS-DATA Series, 70,   2002
  • 3D-momentum imaging of fragment ions of CF4/ CH4 characterized by energy-gain of incident Arq+ ions, Kenji Motohashi, Seiji Tsurubuchi, The fifth Asian International Seminar on Atomic and Molecular Physics -Scientific Program and Book of Abstracts-,   2002
  • Momentum Imaging Spectroscopy for Fragment Ions Produced in Single-Electron Transfer of Arq++N2/ CF4/ CH4 (q=8-11) Collision, K. Motohashi, S. Tsurubuchi, 22th International Conference on Photonic, Electronic, and Atomic Collisions =Abstracts of Contributed papers-,   2001
  • Emission cross sections for H, C and He produced in He++CH4 collisions, K Motohashi, S Tsurubuchi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 33, (22) 5215 - 5224,   2000 11 , Emission cross sections for hydrogen Lyman-alpha, -beta, Balmer-alpha, -beta, C(3s P-3(J')o --> 2p(2) P-3(J), 165.7 nm), C(2p(3) D-3(J')o --> 2p(2) P-3(J), 156.1 nm) and He(2p P-1(1) --> 1s(2) S-1(0), 58.4 Kn) produced in He+ + CH4 collisions are measured in the energy range from 4 eV (cm) to 4000 eV (cm). The emission cross sections of hydrogen Lyman and Palmer series have a plateau above 100 eV. The cross sections of helium and carbon lines decrease rapidly with decreasing collision energy. The branching ratio when an excited hydrogen with n = 2 is produced is estimated to be 2.5 x 10(-2) at 4000 eV by using measured emission cross sections for H-alpha to H-epsilon and by empirical relations.
    DOI
  • Electron-impact cross sections of Ne, S Tsurubuchi, K Arakawa, S Kinokuni, K Motohashi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 33, (18) 3713 - 3723,   2000 09 , Electron-impact absolute emission cross sections were measured for the 3p --> 3s transitions of Ne. Excitation functions of the 3s --> 2p first resonance lines were measured in the energy range from the threshold to 1000 eV by a polarization-free optical method and relative cross sections were normalized to the absolute values, (41.0 +/- 5.4) x 10(-19) cm(2) for the 73.6 nm line and (7.1 +/- 1.0) x 10(-19) cm(2) for the 74.4 nm line, which were determined at 500 eV. The integrated level-excitation cross sections of Suzuki et al for the 1s(2) and 1s(4) levels were combined with the corresponding 3p --> 3s cascade cross sections obtained in this paper to give absolute emission cross sections for the resonance lines. The level-excitation cross sections of the Ist and Isl states in Paschen notation were determined from the threshold to 1000 eV by subtracting 3p --> 3s cascade cross sections from the corresponding 3s --> 2p emission cross sections of the resonance lines. A large cascade contribution is found in the emission cross section of the resonance lines. It is 28.5% for the 73.6 nm line and 49.6% for the 74.4 nm line at 40 eV, and 17.0 and 61.8%, respectively, at 300 eV.
    DOI
  • Compact electron-beam ion trap using NdFeB permanent magnets, K Motohashi, A Moriya, H Yamada, S Tsurubuchi, REVIEW OF SCIENTIFIC INSTRUMENTS, 71, (2) 890 - 892,   2000 02 , A compact electron-beam ion trap (EBIT) as a multiply charged ion source for medium Z, e.g., Ne10+, Ar18+, Kr26+, and so on, has been developed. A pair of NdFeB permanent magnets generates an intense magnetic field (0.64 T) along with the electron-beam axis. The maximum electron-beam energy and current were designed as 10 keV and 30 mA, respectively. Over 95% of the electron beam up to 20 mA was transmitted to an electron collector. All parts, including electrical feedthroughs, are mounted on a con-flat flange with an 8 in. diam. Portability is added to the EBIT because no cooling system for the electromagnet is needed. Hydrogen-like Ar17+ were extracted. (C) 2000 American Institute of Physics. [S0034-6748(00)60202-2].
    DOI
  • High energy operation of the Tokyo-electron beam ion trap/present status, H Kuramoto, H Shimizu, N Nakamura, FJ Currell, D Kato, T Kinugawa, XM Tong, H Watanabe, T Fukami, YM Li, S Ohtani, EJ Sokell, C Yamada, T Hirayama, K Motohashi, S Tsurubuchi, K Okazaki, M Sakurai, MR Tarbutt, JD Silver, REVIEW OF SCIENTIFIC INSTRUMENTS, 71, (2) 687 - 689,   2000 02 , We are using the Tokyo electron beam ion trap (Tokyo-EBIT) to study a wide range of the physics of highly charged ions. Transition wavelengths have been investigated using visible and x-ray spectroscopy. The charge-state distributions of the extracted ions from the trap are shown for the different experimental conditions. Ionization cross sections are measured by observing the time dependence of the charge state evolution in the extracted ions. A brief introduction of the recent studies is given. (C) 2000 American Institute of Physics. [S0034-6748(00)52302-8].
    DOI
  • Recent activities at the Tokyo Electron Beam Ion Trap, Atomic Collision Research in Japan, 25,   1999
  • Development of a compact EBIT using NdFeB permanent magnets, Atomic Collision Research in Japan, 25,   1999
  • A Compact EBIT With NdFeB Permanent Magnets., The 8th International Conference on Ion Sources, Abstract,   1999
  • Development of a Compact EBIT with NdFeB Permanent Magnets., K. Motohashi, A. Moriya, H. Yamada, S. Tsurubuchi, 21st International Conference on the Physics of Electronic and Atomic Collisions, Abstract, 2,   1999
  • M1-Transitions of Ti-like Highly Charged Ions., Physica Scripta, T80,   1999
  • Estimation of Emission Cross Section for CH+(A1Π-X1Σ+ : 419.0-441.0nm)Produced by Electron Impact of CH4 Using Spectral Simulation Technique., Kenji Motohashi, Seiji Tsurubuchi, Journal of the Physical Society of Japan, 68, (1) 64 - 70,   1999
    DOI
  • Emission Cross Section for CH+ Produced by Electron Impact of CH4, Kenji Motohashi, Seiji Tsurubuchi, International Symposium on Electron-Molecule Collisions and swarms -Program and Abstracts-,   1999
  • The present status of the Tokyo electron beam ion trap, N Nakamura, J Asada, FJ Currell, T Fukami, T Hirayama, D Kato, K Motohashi, E Nojikawa, S Ohtani, K Okazaki, M Sakurai, H Shimizu, N Tada, S Tsurubuchi, H Watanabe, REVIEW OF SCIENTIFIC INSTRUMENTS, 69, (2) 694 - 696,   1998 02 , Recent progress of the Tokyo electron beam ion trap (Tokyo-EBIT) project is described. The Tokyo-EBIT is of an original design and construction with several features different from other EBITs in the world. The maximum energy and current of the electron beam are designed to be 340 keV and 300 mA with a magnetic field of 4.5 T. The ongoing and planned physics experiments are described and the results for the initial stage of operation of the Tokyo-EBIT are given. (C) 1998 American Institute of Physics.
    DOI
  • Emission cross section for hydrogen Lyman-α and-β produced in H-+Rg(He, Ne, Ar and Kr)collisions., Atomic Collision Research in Japan, 24,   1998
  • Emission cross sections for hydroden Lyman-α and-β produced in He+/Ar++H2 collisions., Atomic Collision Research in Japan, 24,   1998
  • Characteristics of the Tokyo Electron-Beam Ion Trap, H Watanabe, J Asada, FJ Currell, T Fukami, T Hirayama, K Motohashi, N Nakamura, E Nojikawa, S Ohtani, K Okazaki, M Sakurai, H Shimizu, N Tada, S Tsurubuchi, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 66, (12) 3795 - 3800,   1997 12 , We have constructed a new Electron Beam Ion Trap (EBIT). Over recent months, we have operated this device and obtained some experimental results. In this paper, we show the performance of this EBIT by illustrating these results.
    DOI
  • Emission Cross Sections for the Fragment Species in He++CH4 Collision, K. Motohashi, S. Tsurubuchi, 20th International Conference on The Physics of Electronic and Atomic Collisions -Abstracts of Contributed Papers-, 1,   1997
  • Optical emission spectroscopy of sputtered Al atoms from Al and Al2O3 surfaces interacted with Arq+ (q = 1-9), K Motohashi, S Tsurubuchi, H Shimizu, K Mochiji, H Tanuma, N Kobayashi, PHYSICA SCRIPTA, T73,   1997 , Optical emissions from Al and Al2O3 surfaces bombarded by Arq+ (q = 1-9) were observed in the wavelength range from 250nm to 750nm. The 4s --> 3p and 3d --> 3p doublet transitions of Al atoms were observed. Doppler line profiles of Al (4s(2)S(1/2) --> 3p(2)P(3/2): 396.15nm) transition at 45keV impact energy were observed for various charge state of Arq+. The mean velocity parallel to the surface was calculated by fitting the line profile to the Thompson-Sigmund velocity distribution for the sputtered atoms. Doppler line profiles at lower impact energy (1.84keV) for q = 3 and q = 8 charge state were observed. No significant change for these line profiles was observed. ''Coulomb explosions'' at the Al2O3 surfaces in producing neutral excited atoms were not observed.
  • Extraction of Trapped Ions from The Tokyo EBIS/T, Physica Scripta, (T73) 368 - 370,   1997
    DOI
  • Detector Systems for Use with on Electron Beam Ion Trap, Physica Scripta, (T73) 371 - 372,   1997
    DOI
  • X-ray Spectroscopy at the Tokyo EBIT Facility, Physica Scripta, T73,   1997
  • An Overview of Tokyo Electron Beam Ion Source/Trap at ILS/UEC, Physica Scripta, (T73) 362 - 364,   1997
    DOI
  • Controle System of the Electron Beam Ion Trap at ILS/UEC, Physica Scripta, (T73) 365 - 367,   1997
    DOI
  • Recent Progress of the Tokyo-Electron Beam Ion Trap, Atomic Collision Research In Japan, 23,   1997
  • Emission Cross Sections for Fragment Species Produced in He+H2 and in He+CH4, Atomic Collision Research in Japan, 23,   1997
  • Electron-Impact Emission Cross sections for the Resonance Lines of Ne, Atomic Colission Research In Japan, 23,   1997
  • The Tokyo Electron-Beam Ion Trap Experimental Program, S. Ohtani, J. Asada, T. Fukami, H. Hirayama, K. Motohashi, N. Nakamura, E. Nojikawa, K. Okazaki, H. Shiraishi, M. Sakurai, N. Tada, S. Tsurubuchi, H. Watanabe, 20th International Conference on the Physics of Electronic and Atomic Collisions -Abstracts of Contributed Papers-, 2,   1997
  • Electron-impact emission cross sections of Ar, S Tsurubuchi, T Miyazaki, K Motohashi, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, 29, (9) 1785 - 1801,   1996 05 , Electron impact emission cross sections of Ar were measured for the 4p --> 4s, 5p --> 4s and 4s --> 3p transitions from the threshold to 1000 eV by a polarization-free method. Two different methods were used in determining absolute emission cross sections for the first resonance lines. The first method is to measure the cascade cross sections to the 4s state by detecting visible to near-infrared radiation and the total cascade cross section was then combined with the level excitation cross section to the 4s state to give the emission cross section for the resonance line. The second method is to measure the vacuum ultraviolet sensitivity of the apparatus and an absolute emission cross section for the resonance line was obtained by comparing its spectral intensity with that of the Lyman-alpha radiation produced from H-2 by electron impact. The two results showed good agreement within the experimental errors. The level excitation cross sections to the 1s(2) and 1s(4) states were obtained by subtracting the total cascade cross section to these levels from the corresponding emission cross sections.
    DOI
  • Mean velocity of sputtered Al atoms from Al and Al2O3 surfaces by Ar+ bombardment, Atomic Collision Research in Japan, 22,   1996
  • Emission cross sections for hydrogen and helium atoms produced by He++CH4 collision, Atomic Collision Research in Japan, 22,   1996
  • Dissociative excitation of CH4 by electron impact : Emission cross sections for the fragment species, Chemical Physics, 213, (1/3) 369 - 384,   1996
    DOI
  • Emission cross sections for hydrogen Lyman α produced from He++CH4, 21,   1995
  • Electron-impact emission cross sections of the resonance line of Ar(共著), 19th International Conference on the Physics of Electronic and Atomic Collisions, Abstract, 1,   1995
  • Emission cross sections for fragment species in dissociative excitation of CH4 by electron impact(共著), 19th International Conference on the Physics of Electronic and Atomic Collisions, Abstract, 1,   1995
  • EXCITATION OF THE 3S3P6 STATE OF Ar+ BY ELECTRON IMPACT(共著), JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 63,   1994
    DOI
  • DOPPLER LINE PROFILE OF SPUTTERED Al ATOMS FROM Al AND Al2O3 SURFACES(共著), ATOMIC COLLISION RESEARCH IN JAPAN, 20,   1994
  • EMISSION CROSS SECTIONS FOR EXCITED FRAGMENTS PRODUCED BY ELECTRON IMPACT OF CH4, ATOMIC COLLISION RESEARCH IN JAPAN, 20,   1994
  • Emission cross sections for the 5P→4S transition of Ar by electron impact (共著), Atomic Collision Research in Japan Progress Report, 19,   1993
  • Rotational and vibrational temperatures of excited CH radical by electron impact on CH4, Atomic Collision Research in Japan Progress Report, 19,   1993
  • Dissociative excitation of SiH4 by electron impact : emission cross sections for fragment species (共著), CHEMICAL PHYSICS, 161, (3) 493 - 500,   1991
    DOI
  • Dissociative excitation of SiH4 by electron impact : emission cross sections for the hydrogen Lyman series (共著), CHEMICAL PHYSICS, 155, (3) 401 - 406,   1991
    DOI

Books etc

  • ION-SURFACE INTERACTIONS (ISI-2019)
    E. Yu. Zykova, P. A. Karaseov, A. I. Titov, V. E. Yurasova
    ContributorNational Centre for the Russian Federation  2019 08
    URL
  • ISSP10 Proceedings of the 10th ISSP International Symposium on Nanoscience at Surfaces
    ELSEVIER  2007
    URL
  • INELASTIC ION-SURFACE COLLISIONS
    ELSEVIER  2005
    URL
  • CORRELATIONS, POLARIZATION, AND IONIZATION IN ATOMIC SYSTEMS
    AMERICAN INSTITUTE OF PHYSICS  2002
    URL

Conference Activities & Talks

  • Optical emission spectra on tungsten surfaces irradiated with low energy Ar+ ion beam, H. Igarashi, H. A. sakaue, D. Kato, I. Murakami, K. Motohashi, T. Kenmotsu, K. Furuya, T. Furukawa, Y. Sakai, The Physical Society of Japan 2020 (75th) Annual Meeting,   2020 03 16
  • Comparison of inactivation effect of skin cancer cells between plasma activated medium and anticancer drug, K. Usui, K. Muro, T. Sekiguchi, K. Kato, K. Motohashi, The 67th JSAP Spring Meeting 2020,   2020 03 14
  • Inactivation of skin cancer cells using the medium activated with He – O₂ mixed gas plasma, K. Muro, K. Usui, T. Sekiguchi, K. Kato, K. Motohashi, The 67th JSAP Spring Meeting 2020,   2020 03 14
  • Fluence mesurement of 4MeV-C4+ ion beam guided with the cylindrical glass channel, Kenji Motohashi, 2019 Autum Meeting of the Physical Society of Japan,   2019 09 10 , The Physical Society of Japan
  • Optical emission spectra from Ar+ ions recoiled on tungsten surface by irradiation of Ar+ ion beam, Y. Igarashi, H. A. Sakaue, D. Kato, K. Motohashi, K. Nogami, I. Murakami, T. Kenmotsu, K. Furuya, T. Furukawa, Y. sakai, 44th Annual Meeting of the Atomic Collision Society,   2019 09 06
  • Kinetic energy distribution of slow multiply charged ions transmitted through a cylindrical glass channel, Kenji Motohashi, The 24th International Conference on Ion-Surface Interaction,   2019 08 20 , national Research Nuclear University (MePhI), Guiding of Ar3+ (7.5 keV) ion beam using cylindrical glass channel (CGC) was successfully observed. Small deflection due to tilt of the CGC was observed. Kinetic energy of transmitted ions almost preserved the initial energy. Ion transmission probability increased with an increase of charge injected to the CGC. Negative x displacement of deflected ions at both positive and negative tilt angles suggests that the concave shape contributes to guide of ions more effectively than the convex one.
  • Comparison of inactivation effect using plasma activated medium between skin cancer cells and normal cells, Kounosuke Muro, Kazuhiro Usui, Tatsuya Sekiguchi, Kazunori Kato, Kenji Motohashi,   2019 07 06
  • Comparison of inactivation effect of skin cancer cells between plasma activated medium and anti-cancer agents, Kazuhiro Usui, Kounosuke Muro, Tatsuya Sekiguchi, Kazunori Kato, Kenji Motohashi,   2019 07 06
  • Extraction of Ne ions from cold cathode ion source, Taro Nishimura, Arisa Asahara, Kenji Motohashi,   2019 07 06
  • Extraction of multicharge Ar ions from an electron beam ion source, Kousuke Ohta, Kenji Motohashi,   2019 07 06
  • Comparison of inactivation effect between skin cancer cells and skin normal cells in plasma activated medium, Kounosuke Muro, Kazuhiro Usui, Tatsuya Ono, Kazunori Kato, Kenji Motohashi, The 66th JSAP Spring Meeting, 2019,   2019 03 09 , The Japan Society of Applied Physics
  • Evaluation of guide effect for fullerene ion beam and argon ion beam using cylindrical glass channel, Kenji Motohashi, ECRIS meeting,   2018 12 26
  • Guiding of 7.5 keV Ar3+ ion beam and focusing of 4 MeV C4+ ion beam using cylindrical glass channel, Kenji Motohashi, TMU Symposium on Physics of Highly Charged Ions 2018,   2018 12 16 , Invited, Guiding of Ar3+ (7.5 keV) ion beam using cylindrical glass channel (CGC) was successfully observed. Small deflection due to tilt of the CGC was observed. Kinetic energy of transmitted ions almost preserved the initial energy. Ion transmission probability increased with an increase of charge injected to the CGC. Negative x displacement of deflected ions at both positive and negative tilt angles suggests that the concave shape contributes to guide of ions more effectively than the convex one. Focusing of C4+ (4 MeV) ion beam using the CGC was successfully observed. No deflection of transmitted ion beam was observed. Kinetic energy of transmitted ions almost preserved the initial energy at |θ| ≤ 3º. Flux enhancement of transmitted ions by factor 1.4 was observed in CR-39 etch pits.
  • Transmission characteristics of Ar multicharge Ion Beams on a cylindrical glass channel, Kenji Motohashi, Shu Ishii, Kosuke Aoki, Naoya Tsuruta, Shoutaro Kamon, 43rd Annual Conference of the Atomic Collision Society og Japan,   2018 10 12 , The Atomic Collision Society of Japan, "Ion beam guiding effect" in which a low-energy multiply charged ion beam travels in a capillary tube and a bent tube by charging has been attracting attention. In order to investigate the effect of different shapes of concave and convex on the guide effect, we attempted to measure kinetic energy and scattering angle of the ion beam passing through the cylindrical glass channel. As a result, it was found that the guide effect on the concave surface is larger than the convex surface.
  • Inactivation of skin cancer cells by plasma activated medium, Kounosuke Muro, Kazunori Kato, Kenji Motohashi, 43rd Annual Conference of the Atomic Collision Society og Japan,   2018 10 12 , The Atomic Collision Society of Japan, In order to investigate the effect of the plasma activated medium (PAM), we examined the plasma irradiation time dependence of the PAM and the time (effective time) during which the effect was sustained. Furthermore, in order to investigate whether the plasma directly affects cancer cells or the radicals generated in the PAM are affecting, experiments in which the amount of the PAM at the time of plasma irradiation is also changed are also conducted. As a result, it was found that the PAM irradiated with plasma for 180 seconds had the effect of killing skin cancer cells until about 10 minutes thereafter.
  • Kinetic energy of multiply charged Ar-ion beam guided by a cylindrical glass channel, Kenji Motohashi, Shu Ishii, Kosuke Aoki, The Physical Society of Japan 2018 Autumn Meeting,   2018 09 11 , The Physical Society of Japan, The ion-beam guiding, that is the transmission of low energy multi-charge ions in some tapered or curved insulator capillaries due to electric charging, have been received much attention. However, influence of the effect on shape of the inner wall and the surface condition has not been clarified because tapered capillaries have been used in most of the studies. Furthermore, detail of the ion-beam guiding has also not been clarified because kinetic energy of guided ion beam has not been measured yet. The aim of this study is to evaluate influence of the shape of the inner wall on the guiding effect by measuring the kinetic energy of guided ions.
  • In situ mass analysis of scattered particles in collisions between ions and thiol self-assembled monolayer surfaces terminated with ferrocene, Kensei Kawamura, Muneo Osumi, Kenji Motohashi, The 15th International Symposium on Bioscience and Nanotechnology,   2017 12 01 , Bio-nano Electronics Research Centre, Toyo University, We conducted an in-situ mass spectrometry of atoms or molecules scattered on glass surfaces covered with ferrocene in the presence of energetic Xe or C60 fullerene ions to investigate their inelastic processes involving rearrangement or encapsulation, respectively. This study aims to develop a novel technique for synthesizing and simultaneously refining complexes involving Fe atoms. For example, it is expected that Fe@C60 molecular ions exit a cylindrical or tapered planer channel covered with ferrocene-terminated thiol self-assembled monolayer surfaces (SAMs) via multiple glancing collisions of C60 ions. The mass-to-charge ratio of the scattered ions on the SAM surface was measured by the time-of-flight T and the displacement y of the scattered particle. We successfully measured the charge-state-specific mass spectra of exit ions using the cylindrical and the tapered planar channels.
  • Mass Spectrometry of Fullerene Ions Scattered on Glass Surfaces Covered with Ferrocene Molecules, Kenji Motohashi, Tomoki Tachikawa, Takashi Uchida, The 8th International Symposiumu on Surface Science,   2017 10 23 , The Surface Science Society of Japan, We performed a mass-spectrometric study of cluster ions scattered on solid surfaces covered with ferrocene molecules in the presence of 4.8keV‒C60q+ (q = 1 and 2) ions to investigate their encapsulation process. This study aims to develop a novel technique for synthesizing and simultaneously refining Fe@C60. It is expected that Fe@C60 molecular ions exit a curved or a tapered glass channel covered with ferrocene-terminated thiol self-assembled monolayer surfaces (Fe-thiol-SAMs) via multiple glancing collisions of C60 ions. The mass-to-charge ratio of the scattered ions on the SAM surface was analyzed using the time-of-flight measurement combined with the ion-imaging technique. We successfully measured the charge-state-specific mass spectra of exit ions using cylindrical glass and planar wedge channels. In the case of a planar wedge channel tilted +2° with respect to the C60-ion-beam axis, the peak of mass distribution shifted from ~720 u (~C60) to 750 u (~XC60). Furthermore, we performed an elemental analysis of the scattered clusters deposited on a Si substrate by inductively coupled plasma mass spectrometry. A significant increase of the amount of iron atoms was confirmed compared with a blank and a non-deposited substrates. Therefore, it is considered that XC60 contains FeC60 clusters.
  • Spectroscopic studies on atomic excited state formation in sputtering induced by ion-beam bombardment on tungsten surfaces, D. Kato, H.A. Sakaue, Y. Sakai, T. Kenmotsu, k. Furuya, M. Sakamoto, K. Motohashi, 16th International Conference on Plasma-Facing Materials and Components for Fusion Applications,   2017 05 16 , Institute of Energy and Climate Research, Excited state formations in sputtered tungsten atoms by 35-60 keV Kr+ ion-beam bombardment on polycrystalline tungsten are investigated based on emission lines of the atoms in excited states above the surface. Mean velocities of the excited atoms outgoing along the surface normal are deduced from exponents of decay curves of sputtered W I line intensities in the optical range. The deduced mean normal velocities are almost constant over the incident Kr+ ion energies used in the present experiments. However, emission lines associated with different excited states give different mean velocities. This is interpreted by electronic inelastic processes that involve resonant charge exchange between excited W atoms and surfaces.
  • Mass analyses of clusters exit from ion channels covered with ferrocene in incidence of C60 ions, T. Tachikawa, T. Uchida, K. Motohashi, The 64th JSAP Spring Meeting, 2017,   2017 03 16 , The Japan Society of Applied Physics
  • Transmission properties of low energy multicharge ion beam entering the gap between a pair of optical lenses, Syu Ishii, Yukihito Mase, Kenji Motohashi, The 64th JSPS Spring meeting, 2017,   2017 03 15 , The Japan Society of Applied Physics
  • Influence of atmospheric pressure helium plasma irradiation on skin cancer cells and esophageal cancer cells, Yusuke Ueno, Koichiro Hirasawa, Kazunori Kato, Kenji Motohashi, The 64th JSAP Spring Meeting, 2017,   2017 03 14 , The Japan Society of Applied Physics
  • The energy distributions of 4MeV-Cq+ ions (q=1,4) guided by a cylindrical glass channel, K. Motohashi, Y. Saito, N. Miyawaki, K. Narumi, The 1st QST Takasaki Laboratory Symposium,   2017 01 26 , National Institutes for Quantum and Radiological Science and Technology
  • Transmission propertiies of low energy multi-charge ion beam entering the gap between a pair of optical lenses, Kenji Motohashi, The Annual Meeting of The Atomic Collision Society,   2016 12 11 , The Atomic Collision Society, When Ar3+ ion beam entered the gap between a pair of cylindrical glass lenses and the gap between a pair of flat aluminum optical mirrors, we measured the charge state, energy, and the observation angle of the transmitted ions. We found the guiding effect, that is the ione beam transmission without energy loss, by tilting the channels.
  • Development of a atomospheric pressure plasma reaction analizer and the preliminaly results, Yusuke Ueno, Ko-ichirou Hirasawa, Kenji Motohashi, The 41th Annual Meeting of The Atomic Collision Society,   2016 12 11 , The Atomic Collision Society, We have been developing an analizer of plasma induced reaction of living cancer cells. Preliminary results of optical emission spectra, pH, and electric conductivity were measured during the atomospheric plasma irradiation on the esophagus cancer cells and the skin cancer cells. The spectra of N2, O, and He were observed under He plasma irradiation. The pH and the electric conductivity increased with an increase of irradiation time.
  • Space distribution and polarizability of optical emission on the surface irradiated with ions, H. A. Sakaue, D. kato, I. Murakami, S. Mineta, K. Lee, Y. Sakai, K. Furuya, T. Kenmotsu, K. Motohashi, The 41th Annual Meeting of The Atomic Collision Society of Japan,   2016 12 10 , The Atomic Collision Society of Japan, We observed optical spectra of Balmer series emitted from hydrogen atoms scattered on a tungsten surface in incidence of 35 keV-proton beam. The spacial distributions of emission intensity and polarizability of the Balmer alpha line spectrum were successfully measured. Both distributions were found to be polarized with the scattered direction.
  • C60 ion scattering on a thiol self assembled monolayer surface terminated with ferrocene, Kenji Motohashi, Tomoki Tachikawa, Takashi Uchida, The 41th Annual Meeting of the Atomic Collision Society of Japan,   2016 12 10 , The Atomic Collision Society of Japan, We conducted mass spectroscopy of molecules scattered on solid surfaces covered with ferrocene molecules in the presence of energetic C60 fullerene ions to investigate their encapsulation process. We successfully measured the charge-state-specific mass spectra of exit ions using cylindrical glass and planar wedge channels. In the case of a planar wedge channel tilted 2° with respect to the C60-ion-beam axis, intensity enhancement and reduction were observed at masses around 776u and below 720 u, respectively. Therefore, it is considered that particles with their mass around 776u contain FeC60 molecules.
  • Mas spectroscopy of fullerene ions scattered on glass surfaces covered with ferrocene molecules, Kenji Motohashi, Tomoki Tachikawa, Takashi Uchida, The 14th International Symposium on Bioscience and Nanotechnology,   2016 11 24 , Bio-Nano Electronics Research Center, We conducted mass spectroscopy of molecules scattered on solid surfaces covered with ferrocene molecules in the presence of energetic C60 fullerene ions to investigate their encapsulation process. It is expected that Fe@C60 molecular ions exit a curved or tapered glass channel covered with ferrocene-terminated thiol self-assembled monolayer surfaces (SAMs) via multiple glancing collisions of C60 ions. We successfully measured the charge-state-specific mass spectra of exit ions using cylindrical glass and planar wedge channels. In the case of a planar wedge channel tilted 2° with respect to the C60-ion-beam axis, intensity enhancement and reduction were observed at masses around 776 u and below 720 u, respectively. Therefore, it is considered that particles with their mass around 776 u contain FeC60 molecules.
  • 4.8keV-C60 ion scattering II on a ferrocene terminated thiol self assembled monolayer surface, Kenji Motohashi, 2016 Autumn Meeting of the Physical Society of Japan,   2016 09 14 , The Physical Society of Japan, We conducted mass spectroscopy of molecules scattered on solid surfaces covered with ferrocene molecules in the presence of energetic C60 fullerene ions to investigate their encapsulation process. It is expected that Fe@C60 molecular ions exit a tapered glass channel covered with ferrocene-terminated thiol self-assembled monolayer surfaces (SAMs) via multiple glancing collisions of C60 ions. The mass-to-charge ratio of the scattered ions on the SAM surface was analyzed using the time-of-flight measurement combined with the ion-imaging technique. We successfully measured the charge-state-specific mass spectra of exit ions. In the case of a planar wedge channel tilted 2° with respect to the C60-ion-beam axis, intensity enhancement and reduction were observed at masses around 776 u and below 720 u, respectively. Therefore, it is considered that particles with their mass around 776 u contain FeC60 molecules.
  • Secondary-ion emission from GaN(0001) and dodecanethiol/Au(111) surfaces irradiated with Arq+ (q=3-6) at glancing angle, The 14th International Conference on the Physics of Highly Charged ions,   2008
  • Optical emission spectroscopy of excited atoms sputtered on a Ti surface under irradiation with multicharge Ar ions, The 14th International Conference on the Physics of Highly Charged Ions,   2008
  • Fragmentation and desorption in low-energy highly charged ion collisions with molecules and surfaces, 14th International Conference on the Physics of Highly Charged Ions,   2008
  • Sputtering with slow highly charged ions under glancing incidence, The 8th Asian International Seminar on Atomic and Molecular Physics,   2008
  • Surface chemical analysis by multicharge-ion induced desorption, The 10th Asia Pacific Physics Conference,   2007
  • Analyses of compound-semiconductor surfaces by highly-charged ions, The University of Tokyo International Sympojium and the tenth ISSP International Sympojium on Nanoscience at Surfaces,   2006
  • Secondary ion emission in grazing collisions between highly-charged ions and surfaces -Coincidence experiments with scattered particles-, 7th Asian International Seminar on Atomic and Molecular Physics,   2006
  • Momentum-imaging spectroscopy of secondary ions from GaN and SiC surfaces collided with highly-charged ions at grazing angle, 15th International Workshop on Inelastic Ion - Surface Collisions,   2004

Works

  • National Institute for Fusion Science Atomic and molecular Databese Working Group

Patents

  • 特願2014-264024, 特開2016-124712, 特許6455971
  • 特願2010-29015, 特開2011-165561, 特許5550042
  • 特願1992-271083, 特開平6-97592
  • 特願1992-243625, 特開平6-97957

Research Grants & Projects

  • Study on molecular dissociation by highly-charged-ion impact
  • Potential sputtering of wide-band-gap semiconductors interacted with slow highly-charged ions
  • Study on molecular dissociation by electron impact
  • Spectroscopic study on Coulomb explosion of non-conductive surface by multiple charged ions
  • Study on the dissociation process of molecules by multiply charged ion impact