Kenji Motohashi

Researcher Profile and Settings

Education

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

Association Memberships

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

Research Activities

Research Areas

• Quantum beam science, Quantum beam science
• Plasma science, Plasma science
• Applied physics, Thin film/Surface and interfacial physical properties
• Physics, Atomic/Molecular/Quantum electronics

Research Interests

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

Published Papers

• 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, 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, and Kensei Kawamura, e-J. Surf. Sci. Nanotech., 16, 127 - 131, 05 , Refereed
  https://www.jstage.jst.go.jp/article/ejssnt/16/0/16_127/_article/-char/ja
  DOI
• Guiding of 4MeV C+ and C4+ ion beams using cylindrical glass channel, Kenji Motohashi, Nobumasa Miyawaki, Yuichi Saitoh, Kazumasa Narumi, and Shiro Matoba, Japanese Journal of Applied Physics, 56, 046301-1 - 046301-6, 03 , Refereed
  https://doi.org/10.7567/JJAP.56.046301
  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, Takahiro Kenmotsu, Kenji Furuya, and Kenji Motohashi, Journal of Vacuum Science and Technology A, 33, (6) 061602-1 - 061602-7, 08 , Refereed
  http://dx.doi.org/10.1116/1.4928250
  DOI
• Highly charged ion scattering on single-crystalline (0001) and (000-1) zinc-oxide surfaces, 104, 22 - 28, 01 , Refereed
  DOI
• MOTOHASHI Kenji, NOGAMI Keisuke, SAKAI Yasuhiro, SAKAUE Hiroyuki, KATO Daiji, KENMOTSU Takahiro, 283, 59 - 62, 04 , 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 and 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
• 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, and Shiro Matoba, JAEA Review, 2015-022,   2016 02 , 査読有り, 招待有り
• Surface Chemical Analysis Using Multiply Charged Ions, Kenji Motohashi, e-J. Surf. Sci. Nanotech., 7,   2009

  DOI
• Analyses of GaN (0001) and (000-1) surfaces by highly-charged ions, K. Motohashi, K. Hosoya, M. Imano, S. Tsurubuchi, and A. Koukitu, Surface Science, 601,   2007

  DOI
• Proton sputtering from polycrystalline Al surface interacting with highly charged ions at grazing incidence angle, Kenji Motohashi and Seiji Tsurubuchi, Nuclear Instruments and methods in Physics Research B, 264, (1) 15 - 22,   2007

  DOI
• HIghly Charged Ions - Atoms, Molecules and Solid Surfaces, Kenji Motohashi, Journal of Plasma and Fusion Research, 83, (8) 665 - 670,   2007
• Secondary-Ion Emission in Grazing Collisions between Highly Charged Ions and Surfaces, Kenji Motohashi, Seiji Tsurubuchi, and Akinori Koukitu, J. Phys.: Conference Series, 80,   2007

  DOI
• 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, and M. Kato, National Institute for Fusion Science Research Report, NIFS-DATA-98,   2006
• High-efficiency and low-damage analysis of solid surfaces by use of highly-charged ions, K. Motohashi, S. tsurubuchi, and A. Koukitu, The 21st Century COE program on "Future Nano-Material" News Letter, 4,   2006
• Momentum-imaging spectroscopy of secondary ions from GaN and SiC surfaces collided with highly charged ions at grazing angle, Kenji Motohashi, Seiji Tsurubuchi, Akinori Koukitu, Nuclear Instruments and Methods in Physics Research B, 232, (1-4) 254 - 260,   2005

  DOI
• Emission cross sections in low energy collisions between He+, Ne+ ions and CF4 molecule, Kenji Motohashi, Seiji Tsurubuchi, Journal of Physics B: Atomic, Molecular and Optical Physics, 38, (18) 3339 - 3348,   2005

  DOI
• A new method for analysis and modification of wide-gap semiconductor surfaces by using highly-charged ions, K. Motohashi, S. Tsurubuchi, and A. Koukitu, The 21st Century COE program on "Future Nano-Material" News Letter, 3,   2005
• Fundamental study on atomic structure of compound semiconductor surfaces by highly charged ions, Seiji Tsurubuchi, Kenji Motohashi and Akinori Koukitu,   2004
• Fundamental Study on Atomic Structure of Compound Semiconductor Surfaces, Seiji Tsurubuchi, Kenji Motohashi and Akinori Koukitu, News Letter: The 21st Century COE (center of Excellence) program on "Future Nano-Material", 2,   2004
• A fundamental study on the sputtering processes of wide-gap semiconductors by highly-charged-ion impact, Kenji Motohashi and Seiji Tsurubuchi, News Letter: The 21st Century COE (Center of Excellence) program on "Future Nano-Material",   2004
• A fundamental study on the sputtering processes of wide-gap semiconductors by highly-charged-ion impact, Kenji Motohashi and Seiji Tsurubuchi,   2004
• Momentum-imaging spectroscopy of fragment ions in excitation of molecules by electron impact, Y. Yamaguchi, Y. Iriki, K. Motohashi and S. Tsurubuchi, Atomic Collision Research in Japan -Progress Report-, 29,   2003
• 3D-momentum images of sputtered ions from a SiC surface interacted with highly-charged Ar ions, K. Motohashi, K. Hosoya, M. Tanaka and S. Tsurubuchi, Atomic Collision Research in Japan -Progress report-, 29,   2003
• Energy-gain-characterized 3D momentum-imaging spectroscopy of N⁺ ions produced in Ar^q+ (q=3, 8, 9, 11 and 12) collisions with N₂ molecules, Seiji Tsurubuchi and Kenji Motohashi, Institute of Physics Publishing・Journal of Physics B: Atomic, Molecular and Optical Physics, 36, (18) 3847 - 3863,   2003

  DOI
• 3D-momentum-imaging spectroscopy of fragment ions produced in electron transfer collisions between egergy-gain selected Ar^q+ (q=3, 8, 9, 11 and 12) and CF₄ molecules, Kenji Motohashi and Seiji Tsurubuchi, Institute of Physics Publishing・Journal of Physics B: Atomic, Molecular and Optical Physics, 36, (9) 1811 - 1833,   2003

  DOI
• 3D-momentum imaging of fragment ions of CF₄/ CH₄ characterized by energy-gain of incident Ar^q+ ions, Kenji Motohashi and Seiji Tsurubuchi, The fifth Asian International Seminar on Atomic and Molecular Physics -Scientific Program and Book of Abstracts-,   2002
• 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, and L. Pichl, National Institute for Fusion Science・RESEARCH REPORT NIFS-DATA Series, 70,   2002
• Momentum Imaging Spectroscopy for Fragment Ions Produced in Single-Electron Transfer of Ar^q++N₂/ CF₄/ CH₄ (q=8-11) Collision, K. Motohashi and S. Tsurubuchi, 22th International Conference on Photonic, Electronic, and Atomic Collisions =Abstracts of Contributed papers-,   2001
• High energy operation of the Tokyo-electron beam ion trap/present status, Review of Scientific Instruments, 71, (2,Pt.2) 687 - 689,   2000

  DOI
• Compact electron-beam ion trap using NdFeB permanent magnets, Review of Scientific Instruments, 71, (2,Pt.2) 890 - 892,   2000

  DOI
• Electron-impact cross sections of Ne, Journal of physcs B: Atomic,. Molecular and Optical Physics, 33, (18) 3713 - 3723,   2000

  DOI
• Emission cross sections for H, C and He produced in He⁺+CH₄ collisions, Journal of Physics B, 33, (22) 5215 - 5224,   2000

  DOI
• Emission Cross Section for CH⁺ Produced by Electron Impact of CH₄, Kenji Motohashi and Seiji Tsurubuchi, International Symposium on Electron-Molecule Collisions and swarms -Program and Abstracts-,   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
• M1-Transitions of Ti-like Highly Charged Ions., Physica Scripta, T80,   1999
• Development of a Compact EBIT with NdFeB Permanent Magnets., K. Motohashi, A. Moriya, H. Yamada and S. Tsurubuchi, 21st International Conference on the Physics of Electronic and Atomic Collisions, Abstract, 2,   1999
• A Compact EBIT With NdFeB Permanent Magnets., The 8th International Conference on Ion Sources, Abstract,   1999
• Development of a compact EBIT using NdFeB permanent magnets, Atomic Collision Research in Japan, 25,   1999
• Recent activities at the Tokyo Electron Beam Ion Trap, Atomic Collision Research in Japan, 25,   1999
• The Present Status of Tokyo Electron Beam Ion Trap, Review of Scientific Instrument, 69, (2 Pt.2) 694 - 696,   1998

  DOI
• Emission cross sections for hydroden Lyman-α and-β produced in He⁺/Ar⁺+H₂ collisions., Atomic Collision Research in Japan, 24,   1998
• 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
• 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 and H. Watanabe, 20th International Conference on the Physics of Electronic and Atomic Collisions -Abstracts of Contributed Papers-, 2,   1997
• Electron-Impact Emission Cross sections for the Resonance Lines of Ne, Atomic Colission 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
• Recent Progress of the Tokyo-Electron Beam Ion Trap, Atomic Collision Research In Japan, 23,   1997
• Controle System of the Electron Beam Ion Trap at ILS/UEC, Physica Scripta, (T73) 365 - 367,   1997

  DOI
• An Overview of Tokyo Electron Beam Ion Source/Trap at ILS/UEC, Physica Scripta, (T73) 362 - 364,   1997

  DOI
• X-ray Spectroscopy at the Tokyo EBIT Facility, Physica Scripta, T73,   1997
• Detector Systems for Use with on Electron Beam Ion Trap, Physica Scripta, (T73) 371 - 372,   1997

  DOI
• Extraction of Trapped Ions from The Tokyo EBIS/T, Physica Scripta, (T73) 368 - 370,   1997

  DOI
• Optical Emission Spectroscopy of Sputtered Al Atom From Al and Al₂O₃ Surfaces Interacted with Ar^q+(q=1-9), Physica Scripta, T73,   1997
• Characteristics of the Tokyo Electron Beam Ion Trap, Journal of the Physical Society of Japan, 66, (12) 3795 - 3800,   1997

  DOI
• Emission Cross Sections for the Fragment Species in He⁺+CH₄ Collision, K. Motohashi and S. Tsurubuchi, 20th International Conference on The Physics of Electronic and Atomic Collisions -Abstracts of Contributed Papers-, 1,   1997
• Electron-impact emission cross sections of Ar, Journal of Physics B : Atomic, Molecular and Optical Physics, 29, (9) 1785 - 1801,   1996

  DOI
• 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 and helium atoms produced by He⁺+CH₄ collision, Atomic Collision Research in Japan, 22,   1996
• 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 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
• 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 hydrogen Lyman α produced from He⁺+CH₄, 21,   1995
• EMISSION CROSS SECTIONS FOR EXCITED FRAGMENTS PRODUCED BY ELECTRON IMPACT OF CH₄, ATOMIC COLLISION RESEARCH IN JAPAN, 20,   1994
• DOPPLER LINE PROFILE OF SPUTTERED Al ATOMS FROM Al AND Al₂O₃ SURFACES(共著), ATOMIC COLLISION RESEARCH IN JAPAN, 20,   1994
• EXCITATION OF THE 3S3P⁶ STATE OF Ar⁺ BY ELECTRON IMPACT(共著), JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 63,   1994

  DOI
• Rotational and vibrational temperatures of excited CH radical by electron impact on CH₄, Atomic Collision Research in Japan Progress Report, 19,   1993
• Emission cross sections for the 5P→4S transition of Ar by electron impact (共著), Atomic Collision Research in Japan Progress Report, 19,   1993
• 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
• Dissociative excitation of SiH₄ by electron impact : emission cross sections for fragment species (共著), CHEMICAL PHYSICS, 161, (3) 493 - 500,   1991

  DOI

Books etc

• 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

• 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, and 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, and 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, and 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 and 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, and 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, and 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 and 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, and 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, and 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.
• Sputtering with slow highly charged ions under glancing incidence, The 8th Asian International Seminar on Atomic and Molecular Physics,   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
• 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
• 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
• Surface chemical analysis by multicharge-ion induced desorption, The 10th Asia Pacific Physics Conference,   2007
• 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
• 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
• 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1992-243625, 特開平6-97957
• 特願1992-271083, 特開平6-97592

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