Researcher basic information

• 博士（工学）, 九州大学

• https://researchmap.jp/tomita_kentaro?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201901020432931575

• 70452729

• 201901020432931575

• measurements of electron density and temperature
• Soft X-ray light source
• EUV light source
• laser-aided spectroscopy
• plasma electronics

• Energy Engineering, Applied plasma science, plasma spectroscopy
• Energy Engineering, Fundamental plasma, laser spectroscopy

• Bachelor's degree program, School of Engineering
• Master's degree program, Graduate School of Engineering
• Doctoral (PhD) degree program, Graduate School of Engineering

Research activity information

• Jan. 2022, Center for Low-temperature Plasma Sciences, Nagoya University, Plasma Materials Science Awards
  Study of high spatio-temporal resolution measurement of plasma electron density
  Kentaro Tomita, 受賞理由：「プロセスプラズマからEUV光源プラズマまで多様な対象に対するレーザトムソン散乱法によるプラズマ電子密度の高時空間分解能測定の研究成果は、世界をけん引する顕著な業績であり、プラズマ材料科学の進展に大きく貢献するものである」, International academic award, 29216835
• Nov. 2020, 量子科学技術研究開発機構 核融合エネルギー部門, 令和元年度JT-60共同研究優秀賞
  レーザー光脱離およびトムソン散乱法を用いたNBI用負イオン源内の負イオン分布計測
  富田 健太郎、小島 有志、平塚;淳一、柏木 美恵子、市川雅浩
• Apr. 2019, Ministry of Education, Culture, Sports, Science and Technology, The Commendation for Science and Technology by the Minister of Education, The Young Scientists’ Prize Culture, Sports, Science and Technology
  Kentaro Tomita
• Mar. 2018, 日本応用物理学会プラズマエレクトロニクス分科会, 2018 Plasma Electronics Award
  Kentaro Tomita
• Feb. 2018, 一般社団法人照明学会, 2018年度(第30回)照明学会論文賞
  堀内 誠;山形 幸彦;堤 晋一;富田 健太郎;真鍋 由雄
• Aug. 2014, 電気学会, 電気学会優秀論文発表A賞
  Kentaro Tomita
• May 2014, 5th International Conference on Plasma Medicine (ICPM5), J. M. Pouvesle, The Award Committee of ICPM5, Early Career Presentation Awards (ECPA)
  Kentaro Tomita
• Apr. 2014, 大阪大学レーザーエネルギー学研究センター, 大阪大学レーザーエネルギー学研究センターシンポジウム2014ベストポスター賞
  富田健太郎
• Sep. 2013, 電気学会, 優秀論文発表賞
  富田健太郎
• Sep. 2007, 応用物理学会, 講演奨励賞
  富田健太郎
• Oct. 2004, 応用物理学会, プラズマエレクトロニクスサマースクール優秀講演賞
  富田健太郎

• Electron Density Structure Measurements With Scattered Intense Laser Beam
  K. Sakai; K. Himeno; S. J. Tanaka; T. Asai; T. Minami; Y. Abe; F. Nikaido; K. Kuramoto; M. Kanasaki; H. Kiriyama; A. Kon; K. Kondo; N. Nakanii; W. Y. Woon; C. M. Chu; K. T. Wu; C. S. Jao; Y. L. Liu; T. A. Pikuz; H. Kohri; A. O. Tokiyasu; S. Isayama; H. S. Kumar; K. Tomita; Y. Fukuda; Y. Kuramitsu
  Contributions to Plasma Physics, Wiley, 23 May 2025, [Peer-reviewed]
  Scientific journal, ABSTRACT
  
  Short‐pulse intense lasers have the potential to model extreme astrophysical environments in laboratories. Although there are diagnostics for energetic electrons and ions resulting from laser‐plasma interactions, the diagnostics to measure velocity distribution functions at the interaction region of the laser and plasma are limited. We have been developing the diagnostics of the interaction between the intense laser and plasma using scattered intense laser. We performed experiments to measure electron density by observing the spatial distributions and the ratio of horizontal to vertical polarization components of the scattered laser beam using optical imaging. The observed ratio of polarization components is consistent with the drive laser beam, indicating the observed light originates from the drive laser. Imaging of the scattered light shows the structure of electron density, the zero moment of the electron velocity distribution function, interacting with the intense laser. We observed the change of structure due to the laser pre‐pulse that destroys the target before the arrival of the main pulse.
• Mechanism of generating collisionless shock in magnetized gas plasma driven by laser-ablated target plasma
  S. Matsukiyo; K. Oshida; S. Isayama; R. Yamazaki; T. Morita; T. Takezaki; Y. Kuramitsu; S. J. Tanaka; T. Sano; K. Tomita; Y. Sakawa
  Physics of Plasmas, 31, 11, AIP Publishing, 01 Nov. 2024, [Peer-reviewed]
  Scientific journal, The mechanism of generating collisionless shock in magnetized gas plasma driven by laser-ablated target plasma is investigated by using one-dimensional full particle-in-cell simulation. The effect of finite injection time of target plasma, mimicking the finite width of laser pulse, is taken into account. It was found that the formation of a seed-shock requires a precursor. The precursor is driven by gyrating ions, and its origin varies depending on the injection time of the target plasma. When the injection time is short, the target plasma entering the gas plasma creates a precursor; otherwise, gas ions reflected by the strong piston effect of the target plasma create a precursor. The precursor compresses the background gas plasma, and subsequently, a compressed seed-shock forms in the gas plasma. The parameter dependence on the formation process and propagation characteristics of the seed-shock was discussed. It was confirmed that the seed-shock propagates through the gas plasma exhibiting behavior similar to the shock front of supercritical shocks.
• Competition of magnetic reconnections in self-generated and external magnetic fields
  K. Sakai; T.Y. Huang; N. Khasanah; N. Bolouki; H.H. Chu; T. Moritaka; Y. Sakawa; T. Sano; K. Tomita; S. Matsukiyo; T. Morita; H. Takabe; R. Yamazaki; R. Yasuhara; H. Habara; Y. Kuramitsu
  High Energy Density Physics, Sep. 2024, [Peer-reviewed]
  Scientific journal
• Laser Thomson scattering measurements around magnetized model in rarefied argon arcjet plume
  H. Katsurayama; R. Wada; K. Moriyama; K. Tomita
  Journal of Instrumentation, 19, 01, C01048, C01048, IOP Publishing, 01 Jan. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  To elucidate the role of the Hall effect in magnetohydrodynamic (MHD) aerobraking in rarefied flows,we measured the radial distributions of electron temperature and density in front of a magnetized model in a rarefied argon arcjet wind tunnel using the laser Thomson scattering method. We also developed a water-cooled magnetized model to prevent thermal demagnetization during the measurement. The measured electron densitydistributions were inexcellent agreement with computational fluid dynamics (CFD) predictions. It was also found that the magnetic field had little effect on the electron density distribution around the model. In the case without the magnetic field, the measured electron temperature almost agreed with the CFD prediction. However, the measured electron temperature increase caused by applying themagnetic field was about 1,000 K less than that of the CFD prediction. This discrepancy indicates that the location of an insulating boundary in the plasma is far from the model.
• Joint measurement of electron density, temperature, and emission spectrum of Nd:YAG laser-produced tin plasma
  Y. Pan; K. Tomita; A. Sunahara; A. Sasaki; K. Nishihara
  Applied Physics Letters, 123, 20, AIP Publishing, 13 Nov. 2023, [Peer-reviewed]
  Scientific journal, We present the results of joint measurements of electron density (ne), temperature (Te), and emission spectra of an Nd:YAG-driven tin plasma. Collective Thomson scattering provides space- and time-resolved ne and Te data during drive laser irradiation, and extreme ultraviolet (EUV) emission spectra, which is space-resolved in the target normal, are measured using a flat-field grazing incidence spectrometer (GIS). As the distance from the target increased, the emission intensity quickly decreases, and the peaks of the spectra gradually shift to longer wavelengths. This can be explained by the rapid decrease in ne, and thus, self-absorption, with an increase in distance. We obtain the EUV spectra by calculating the transfer of photons along the line-of-sight of the GIS, using theoretical emissivity and opacity, and applying the measured spatial distribution of ne and Te. The results quantitatively demonstrate that the self-absorption effect is significant; the emission from the core regions is mostly reabsorbed by the surrounding plasma. The calculated spectra are compared with the measured spectra. While good agreement is achieved in the spectral region of 13.3 and 15.3 nm, considerable differences are found in the 12.5–13  and 15.5–17.5 nm region. The results demonstrate the significance of this joint measurement for further validation of the atomic process model considering self-absorption effect, which is critical for the future high-density, solid laser-driven EUV source.
• Optimization of extreme ultra-violet light emitted from the CO₂ laser-irradiated tin plasmas using 2D radiation hydrodynamic simulations
  Atsushi Sunahara; Ahmed Hassanein; Kentaro Tomita; Shinichi Namba; Takeshi Higashiguchi
  Optics Express, 31, 20, 31780, 31780, Optica Publishing Group, 11 Sep. 2023, [Peer-reviewed]
  Scientific journal, We studied Extreme Ultra-Violet (EUV) emission characteristics of the 13.5 nm wavelength from CO₂ laser-irradiated pre-formed tin plasmas using 2D radiation hydrodynamic simulations. Our results indicate that when a CO₂ laser irradiates pre-formed tin plasma, the heated plasma expands towards the surrounding plasma, steepening the density at the ablation front and lowering the density near the laser axis due to the transverse motion of the plasma. Consequently, the laser absorption fraction decreases, and the contribution to EUV output from the ablation front becomes dominant over that from the low-density plasmas. We estimated that an EUV conversion efficiency of 10% from laser to EUV emission could be achieved with a larger laser spot size, shortened laser pulse width, and longer pre-formed plasma density scale length. Our results offer one optimizing solution to achieve an efficient and powerful EUV light source for the next-generation semiconductors.
• Thomson scattering measurements of electron temperature and electron density in laser-driven Gd plasmas
  Yiming Pan; Atsushi Sunahara; Shinichi Namba; Takeshi Higashiguchi; Kentaro Tomita
  Journal of Physics D: Applied Physics, 56, 40, 405203, 405203, IOP Publishing, 12 Jul. 2023, [Peer-reviewed]
  Scientific journal, Abstract
  
  In this study, we demonstrate the laser intensity scaling of electron temperature in Gd laser-produced plasmas (LPPs) through experiment and simulation. The spatial and temporal profiles of electron density n_e and temperature T_e in Gd LPPs were directly measured during a drive laser pulse duration of 7 ns at a laser wavelength of 1064 nm using collective Thomson scattering. We found that the measured maximum T_e value in Gd LPPs increases with increasing laser intensity I_L , with the dependence , in the I_L range of 10¹⁰– . Radiation-hydrodynamic simulation code of the STAR-2D was performed under identical conditions to those used in the experiment, and extended further to higher laser intensities of up to ; the simulated T_e was found to be in good agreement with the experimental data over the used I_L range. The simulation indicates that higher overall maximum T_e typically exists 50–70  above the target and modifies the dependence as . Experiments reveal that a laser intensity of is required to achieve the optimum condition ( 100 eV and ion charge states , at – ) for efficient beyond extreme ultraviolet (EUV) light source. In addition, two spot sizes (150 and 250 in diameter) were used to study the effect of the spot size on the T_e profile. Our experimental findings, supported by the simulations, show that larger spots can create uniform T_e profiles, higher maximum T_e , and larger high-T_e regions in LPPs. The results and scaling laws presented in this study provide important information for developing more powerful and energy-efficient EUV light sources.
• Observation of plasma inflows in laser-produced Sn plasma and their contribution to extreme-ultraviolet light output enhancement
  Kentaro Tomita; Yiming Pan; Atsushi Sunahara; Kouichiro Kouge; Hakaru Mizoguchi; Katsunobu Nishihara
  Scientific Reports, 13, 1, Springer Science and Business Media LLC, 01 Feb. 2023, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal, Abstract
  
  Plasma dynamics are governed by electron density (n_e), electron temperature (T_e), and radiative energy transfer as well as by macroscopic flows. However, plasma flow-velocity fields (v_flow) inside laser-produced plasmas (LPPs) have rarely been measured, owing to their small sizes (< 1 mm) and short lifetimes (< 100 ns). Herein, we report, for the first time, two-dimensional (2D) v_flow measurements of Sn-LPPs (“double-pulse” scheme with a CO₂ laser) for extreme-ultraviolet (EUV) light sources for semiconductor lithography using the collective Thomson scattering technique, which is typically used to measure n_e, T_e, and averaged ionic charge (Z) of plasmas. Inside the EUV source, we observed plasma inflow speed exceeding 10⁴ m/s magnitudes toward a plasma central axis from its peripheral regions. The time-resolved 2D profiles of n_e, T_e, Z, and v_flow indicate that the plasma inflows maintain the EUV source at a temperature suitable (25 eV < T_e < 40 eV) for EUV light emission at a high density (n_e > 3 × 10²⁴ m⁻³) and for a relatively long time (> 10 ns), resulting increment of total EUV light emission. These results indicate that controlling the plasma flow can improve EUV light output and that there is potential to increase the EUV output further.
• Investigation of dynamics of laser-produced carbon plasma during the laser irradiation using collective Thomson scattering
  Yiming Pan; Kentaro Tomita; Yukihiko Yamagata; Atsushi Sunahara; Katsunobu Nishihara
  Journal of Physics D: Applied Physics, 56, 2, 025201, 025201, IOP Publishing, 08 Dec. 2022, [Peer-reviewed]
  Scientific journal, Abstract
  
  Plasma temperature, density, and flow velocity are the critical physical properties of laser produced plasma (LPP) to reveal the ablation dynamics, energy transport, and hydrodynamic evolution. In the time window during and just after laser irradiation, experimental data are very scarce so that many theoretical models remain untested. Here we report a clear evolution history of LPP expansion dynamics within 0–14 ns after the laser peak and in a region very close to the target (0.13–0.6 mm). A table-top Nd:YAG laser (intensity 6 × 10⁹ W cm⁻², pulse 7 ns) was used to generate the LPP from a planar graphite target, whose width was arranged to be smaller than the laser spot diameter to produce a one-dimensional planar expansion plasma near the target. The electron density ( ), temperature ( ), and drift velocity ( ) in the LPPs were measured using the ion feature of collective Thomson scattering, providing a space- and time-resolved 2D profile of the LPP. The experimental observations made it possible for the expansion dynamics to be compared directly with the LPP expansion models. The results suggest that during the laser pulse, the LPP is approximately isothermal and expands predominantly one-dimensionally in the target normal direction, in which the LPP drift velocity is found to increase linearly with distance. The linear extrapolation of the velocity indicates that the LPP has a considerable velocity at the initial target surface; this velocity is approximately the speed of sound derived from the observed . The experimental results were found to be in moderate agreement with the 1D self-similar isothermal expansion model. The ratio of the internal to kinetic energy in the observed area was ∼0.6, as predicted by the isothermal expansion model. The experimental findings were compared with the results of the 2D hybrid code STAR, and good agreement was obtained.
• Direct observations of pure electron outflow in magnetic reconnection
  K. Sakai; T. Moritaka; T. Morita; K. Tomita; T. Minami; T. Nishimoto; S. Egashira; M. Ota; Y. Sakawa; N. Ozaki; R. Kodama; T. Kojima; T. Takezaki; R. Yamazaki; S. J. Tanaka; K. Aihara; M. Koenig; B. Albertazzi; P. Mabey; N. Woolsey; S. Matsukiyo; H. Takabe; M. Hoshino; Y. Kuramitsu
  Scientific Reports, 12, 1, Springer Science and Business Media LLC, Dec. 2022, [Peer-reviewed]
  Scientific journal, Abstract
  
  Magnetic reconnection is a universal process in space, astrophysical, and laboratory plasmas. It alters magnetic field topology and results in energy release to the plasma. Here we report the experimental results of a pure electron outflow in magnetic reconnection, which is not accompanied with ion flows. By controlling an applied magnetic field in a laser produced plasma, we have constructed an experiment that magnetizes the electrons but not the ions. This allows us to isolate the electron dynamics from the ions. Collective Thomson scattering measurements reveal the electron Alfvénic outflow without ion outflow. The resultant plasmoid and whistler waves are observed with the magnetic induction probe measurements. We observe the unique features of electron-scale magnetic reconnection simultaneously in laser produced plasmas, including global structures, local plasma parameters, magnetic field, and waves.
• Detection of current-sheet and bipolar ion flows in a self-generated antiparallel magnetic field of laser-produced plasmas for magnetic reconnection research
  T. Morita; T. Kojima; S. Matsuo; S. Matsukiyo; S. Isayama; R. Yamazaki; S. J. Tanaka; K. Aihara; Y. Sato; J. Shiota; Y. Pan; K. Tomita; T. Takezaki; Y. Kuramitsu; K. Sakai; S. Egashira; H. Ishihara; O. Kuramoto; Y. Matsumoto; K. Maeda; Y. Sakawa
  Physical Review E, 106, 5, American Physical Society (APS), 10 Nov. 2022, [Peer-reviewed]
  Scientific journal
• High-power laser experiment on developing supercritical shock propagating in homogeneously magnetized plasma of ambient gas origin
  S. Matsukiyo; R. Yamazaki; T. Morita; K. Tomita; Y. Kuramitsu; T. Sano; S. J. Tanaka; T. Takezaki; S. Isayama; T. Higuchi; H. Murakami; Y. Horie; N. Katsuki; R. Hatsuyama; M. Edamoto; H. Nishioka; M. Takagi; T. Kojima; S. Tomita; N. Ishizaka; S. Kakuchi; S. Sei; K. Sugiyama; K. Aihara; S. Kambayashi; M. Ota; S. Egashira; T. Izumi; T. Minami; Y. Nakagawa; K. Sakai; M. Iwamoto; N. Ozaki; Y. Sakawa
  Physical Review E, 106, 2, American Physical Society (APS), 26 Aug. 2022, [Peer-reviewed]
  Scientific journal
• Application of Thomson scattering system toward direct measurement of extraction surface of the negative ion beam
  J Hiratsuka; K Tomita; M Kashiwagi; A Kojima; G Q Saquilayan; T Kaihori; M Ichikawa; M Kisaki; H Tobari; K Watanabe
  Journal of Physics: Conference Series, 2244, 1, 012047, 012047, IOP Publishing, 01 Apr. 2022, [Peer-reviewed]
  Scientific journal, Abstract
  
  As a challenge to measure the extraction surface of the negative ion beam, a laser Thomson scattering system with high spatial resolution was applied to a weakly ionized plasma in a negative ion source for the first time. The first target was to measure electron density around extraction region because shape of the extraction surface can be estimated by electron spatial profile. However, stray light by injected laser, filament and plasma was too intense compared to signal from the low density region. To solve this, a triple grating spectroscopy and a multilayer black screen were introduced, and the laser spot size was minimized to reduce slit sizes of the spectroscopy. As a result, electron density was successfully measured accurately in low density region. From an error estimation, measurement of electron density 3 × 10¹⁶ m^-3 with spatial resolution of 0.5 mm at extraction region can be realized with accumulation of signals from multiple laser shots. This system can contribute to the understanding of the mechanism of formation of the extraction surface, which is a long-term issue in the negative ion source.
• Feasibility study on reactive ion etching occurrence in EUV-induced photoionized hydrogen plasmas based on electron temperature and electron density measurements
  Kouichiro Kouge; Kentaro Tomita; Junya Hotta; Yiming Pan; Hiroaki Tomuro; Tatsuya Yanagida; Kiichiro Uchino; Naoji Yamamoto
  Japanese Journal of Applied Physics, IOP Publishing, 11 Mar. 2022, [Peer-reviewed], [Corresponding author]
  Scientific journal, Abstract
  
  Temporal evolutions of electron temperature (T_e) and electron density (n_e) of photoionized hydrogen plasmas, which were induced by radiation from laser-produced Sn-plasma EUV sources, were measured using the Laser Thomson Scattering (LTS) technique. Measured T_e and n_e ranged from 0.5–2.5 eV and 10¹⁶–10¹⁸ m^-3, respectively, for hydrogen pressures of 50–400 Pa. The T_e of this EUV-induced hydrogen plasma decayed with the thermal relaxation time between electrons and gases. The maximum value of T_e in the time variation depended on hydrogen pressure. The lower the pressure, the higher the maximum T_e, and it reached approximately 2 eV at 50 Pa. The sheath potential between the EUV-induced hydrogen plasma and the unbiased wall might be exceeded 6 eV at 50 Pa, which is sufficient to enhance the removal of Sn-debris from a Mo/Si multilayer mirror via reactive ion etching processes.
• High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest
  R. Yamazaki; S. Matsukiyo; T. Morita; S. J. Tanaka; T. Umeda; K. Aihara; M. Edamoto; S. Egashira; R. Hatsuyama; T. Higuchi; T. Hihara; Y. Horie; M. Hoshino; A. Ishii; N. Ishizaka; Y. Itadani; T. Izumi; S. Kambayashi; S. Kakuchi; N. Katsuki; R. Kawamura; Y. Kawamura; S. Kisaka; T. Kojima; A. Konuma; R. Kumar; T. Minami; I. Miyata; T. Moritaka; Y. Murakami; K. Nagashima; Y. Nakagawa; T. Nishimoto; Y. Nishioka; Y. Ohira; N. Ohnishi; M. Ota; N. Ozaki; T. Sano; K. Sakai; S. Sei; J. Shiota; Y. Shoji; K. Sugiyama; D. Suzuki; M. Takagi; H. Toda; S. Tomita; S. Tomiya; H. Yoneda; T. Takezaki; K. Tomita; Y. Kuramitsu; Y. Sakawa
  Physical Review E, 105, 2, American Physical Society (APS), 11 Feb. 2022, [Peer-reviewed]
  Scientific journal
• Functional nitrogen science based on plasma processing: quantum devices, photocatalysts and activation of plant defense and immune systems
  Toshiro Kaneko; KATO Hiromitsu; Muneaki Yamamoto; Tomoko Yoshida; Pankaj Attri; Kazunori Koga; Kazuyuki Kuchitsu; Sugihiro Ando; Yasuhiro Nishikawa; Kentaro Tomita; Ono Ryo; ITO Tsuyohito; Koji Eriguchi; Tomohiro Nozaki; Takayoshi TSUTSUMI; Kenji Ishikawa
  Japanese Journal of Applied Physics, 61, SA, SA0805, Dec. 2021, [Peer-reviewed], [Invited]
  English, Scientific journal
• Time-resolved two-dimensional measurements of the electron density, electron temperature, and drift velocity of laser-produced carbon plasmas using the ion feature of collective laser Thomson scattering
  Yiming Pan; Kentaro Tomita; Kiichiro Uchino; Atsushi Sunahara; Katsunobu Nishihara
  Applied Physics Express, 14, 6, 066001, 066001, IOP Publishing, 01 Jun. 2021, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Time-resolved spatial profiles of electron density and temperature in hydrogen plasmas induced by radiation from laser-produced tin plasmas for extreme ultraviolet lithography light sources
  Kouichiro Kouge; Kentaro Tomita; Junya Hotta; Yiming Pan; Hiroaki Tomuro; Masayuki Morita; Tatsuya Yanagida; Kiichiro Uchino; Naoji Yamamoto
  Japanese Journal of Applied Physics, 60, 6, 066002, 066002, IOP Publishing, 01 Jun. 2021, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Measurements of spatial distributions of electron density and temperature of 450 MHz UHF plasma using laser Thomson scattering
  Yiming Pan; Kentaro Tomita; Yoshinobu Kawai; Masaaki Matsukuma; Kiichiro Uchino
  Japanese Journal of Applied Physics, 60, SA, SAAB03, SAAB03, IOP Publishing, 01 Jan. 2021, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Collective Thomson scattering in non-equilibrium laser produced two-stream plasmas
  K. Sakai; S. Isayama; N. Bolouki; M. S. Habibi; Y. L. Liu; Y. H. Hsieh; H. H. Chu; J. Wang; S. H. Chen; T. Morita; K. Tomita; R. Yamazaki; Y. Sakawa; S. Matsukiyo; Y. Kuramitsu
  Physics of Plasmas, 27, 10, 103104, 103104, AIP Publishing, Oct. 2020, [Peer-reviewed]
  English, Scientific journal
• Local plasma parameter measurements in colliding laser-produced plasmas for studying magnetic reconnection
  T. Morita; K. Tomita; K. Sakai; M. Takagi; K. Aihara; M. Edamoto; S. Egashira; T. Higuchi; N. Ishizaka; T. Izumi; S. Kakuchi; T. Kojima; Y. Kuramitsu; S. Matsukiyo; Y. Nakagawa; T. Minami; H. Murakami; Y. Nishioka; M. Ota; T. Sano; S. Sei; K. Sugiyama; S.J. Tanaka; R. Yamazaki; Y. Sakawa
  High Energy Density Physics, 36, 100754, 100754, Elsevier {BV}, Aug. 2020, [Peer-reviewed]
  Scientific journal
• Measurement of electron velocity distribution function in a pulsed positive streamer discharge in atmospheric-pressure air
  Kentaro Tomita; Yuki Inada; Atsushi Komuro; Xiang Zhang; Kiichiro Uchino; Ryo Ono
  Journal of Physics D: Applied Physics, {IOP} Publishing, Feb. 2020, [Peer-reviewed], [Lead author]
• Anomalous plasma acceleration in colliding high-power laser-produced plasmas
  T. Morita; K. Nagashima; M. Edamoto; K. Tomita; T. Sano; Y. Itadani; R. Kumar; M. Ota; S. Egashira; R. Yamazaki; S. J. Tanaka; S. Tomita; S. Tomiya; H. Toda; I. Miyata; S. Kakuchi; S. Sei; N. Ishizaka; S. Matsukiyo; Y. Kuramitsu; Y. Ohira; M. Hoshino; Y. Sakawa
  Phys. Plasmas, 26, 90702, Oct. 2019, [Peer-reviewed]
  English, Scientific journal
• Magnetic Reconnection in Self-Generated and Externally Applied Magnetic Fields in Laser-Produced Plasmas
  Taichi Morita; Masafumi Edamoto; Yuki Nishioka; Takayoshi Sano; Masato Ota; Shunsuke Egashira; Ryo Yamazaki; Shuta Tanaka; Sara Tomita; Hirofumi Toda; Itaru Miyata; Ayato Shinoda; Shin Kakuchi; Shuto Sei; Natsuki Ishizaka; Riko Kawamura; Kei Sugiyama; Daisuke Suzuki; Sara Takayama; Kentaro Tomita; Yasuhiro Kuramitsu; Takumi Minami; Kentaro Sakai; Shuichi Matsukiyo; Yumi Horie; Takumi Higuchi; Taichi Takezaki; Youichi Sakawa
  Sep. 2019
  English
• Laser Thomson Scattering Diagnostics for Streamer Discharge in HE Gas
  K. Eguchi; R. Fujita; D. Wang; K. Tomita; T. Namihira
  IEEE International Pulsed Power Conference, 2019-June, Jun. 2019
  International conference proceedings
• Collective Thomson Scattering Measurements of Electron Feature Using Stimulated Brillouin Scattering in Laser-Produced Plasmas
  N. Boloukia; K. Sakai; T.Y. Huang; S. Isayama; Y.L. Liu; C.W. Peng; C.H. Chen; N. Khasanah; H.H. Chu; T. Moritaka; K. Tomita; Y. Sato; K. Uchino; T. Morita; S. Matsukiyo; Y. Hara; H. Shimogawara; Y. Sakawa; S. Sakata; S. Kojima; S. Fujioka; Y. Shoji; S. Tomiya; R. Yamazaki; M. Koenig; Y. Kuramitsu
  High Energy Density Physics DOI: 10.1016/j.hedp.2019.06.002, Jun. 2019, [Peer-reviewed]
  English, Scientific journal
• VHF Plasma CVD Synthesis of Photochromic ZnO Nanoparticle
  H. Kajiyama; S. Kuboyama; A. Otomo; H. Uyama; T. Matsuura; S. Inoue; Y. Matsumura; K. Takata; K. Tomita; K. Uchino
  MRS advances, https://doi.org/10.1557/adv., Feb. 2019, [Peer-reviewed]
  English, Scientific journal
• Observation of the whole Thomson scattering spectrum of laser-produced plasmas for EUV light sources
  Y. Sato; R. Fukada; F. Ito; K. Tomita; K. Uchino
  Engineering Sciences Reports, Kyushu University, 40, 11, 15, Feb. 2019, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Investigation on chemically non-equilibrium arc behaviors of different gas media during arc decay phase in a model circuit breaker
  H. Sun; Y. Wu; Y. Tanaka; K. Tomita; M. Rong
  Journal of Physics D: Applied Physics, 52, 75202, Dec. 2018, [Peer-reviewed]
  English, Scientific journal
• Determination of Spatiotemporal Structure of Fluctuations by Statistical Averaging Method
  Y. Kawachi; S. Inagaki; K. Tomita; K. Yamasaki; F. Kin; Y. Kosuga; M. Sasaki; Y. Nagashima; N. Kasuya; K. Hasamada; B. Zhang; A. Fujisawa
  Plasma and Fusion Research, 13, 3401105, Aug. 2018, [Peer-reviewed]
  English, Scientific journal
• Magnetic reconnection driven by electron dynamics
  Y. Kuramitsu; T. Moritaka; Y. Sakawa; T. Morita; T. Sano; M. Koenig; C. D. Gregory; N. Woolsey; K. Tomita; H. Takabe; Y. L. Liu; S. H. Chen; S. Matsukiyo; M. Hoshino
  Nature communications, 9, 5109, Aug. 2018, [Peer-reviewed]
  English, Scientific journal
• Competition of magnetic reconnections driven by self-generated magnetic fields and an external magnetic field
  Y. Kuramitsu; K. Sakai; T.Y. Huang; N. Khasanah; N. Bolouki; H.H. Chu; T. Moritaka; Y. Sakawa; Y. Hara; T. Sano; K. Tomita; Y. Sato; K. Uchino; S. Matsukiyo; T. Morita; H. Takabe; R. Yamazaki
  May 2018
  English
• Study of driven magnetic reconnection in high-power laser- produced plasma
  T. Morita; K. Nagashima; M. Edamoto; Y. Itadani; T. Sano; R. Kumar; M. Ota; S. Egashira; R. Yamazaki; S. Tanaka; S. Tomiya; H. Toda; I. Miyata; S. Kakuchi; S. Sei; N. Ishizaka; S. Tomita; K. Tomita; Y. Kuramitsu; S. Matsukiyo; Y. Sakawa
  May 2018
  English
• Thermal re-ignition processes of switching arcs with various gas-blast using voltage application highly controlled by powersemiconductors
  Tomoyuki Nakano; Yasunori Tanaka; K. Murai; Y. Uesugi; T. Ishijima; K. Tomita; K. Suzuki; T. Shinkai
  Journal of Physics D: Applied Physics, 51, 21, 215202, Institute of Physics Publishing, 30 Apr. 2018, [Peer-reviewed]
  English, Scientific journal
• The Development of a System for Measuring the Junction Temperatures of Multiple LEDs on a Package Simultaneously by Using Pulsed-laser Raman Scattering
  M. Horiuchi; Y. Yamagata; S. Tsutsumi; K. Tomita; Y. Manabe
  Journal of Science and Technology in Lighting, 41, 101, 107, The Illuminating Engineering Institute of Japan, Mar. 2018, [Peer-reviewed]
  English, Scientific journal,

  This paper details a novel method consisting of employing a pulsed-laser Raman scattering technique to estimate junction temperatures of several LED chips arranged in a straight line on a phosphor-less blue-LED package and a phosphor-resin coated blue-LED package. By using a sheet-shaped irradiation pattern, each of the GaN-E₂^H Raman spectra from several chips mounted straight on a phosphor-less blue LED package was observed at the same time and the junction temperature of each chip was estimated successfully by means of each Raman shift during operation despite the existence of strong LED emission. In addition, the GaN-E₂^H Raman signal from the phosphor-resin coated blue-LED was observed for the first time by using 633 nm laser to reduce the negative influence from the phosphor and light diffusing substances in the resin. It is concluded that this technique would be a useful method for a remote and standard system for 2D mapping of the junction temperatures of blue-LED packages.

• Evaluation of arc quenching characteristics of various gases using power semiconductors
  Tomoyuki Nakano; Yasunori Tanaka; K. Murai; Y. Uesugi; T. Ishijima; K. Tomita; K. Suzuki; T. Shinkai
  JOURNAL OF PHYSICS D-APPLIED PHYSICS, 50, 48, 485602, Dec. 2017, [Peer-reviewed]
  English, Scientific journal
• Design of compact dispersion interferometer with a high efficiency nonlinear crystal and a low power CO2 laser
  T. Akiyama; S. Yoshimura; K. Tomita; N. Shirai; T. Murakami; K. Urabe
  JOURNAL OF INSTRUMENTATION, 12, C12028, Dec. 2017, [Peer-reviewed]
  English, Scientific journal
• Time-resolved two-dimensional profiles of electron density and temperature of laser-produced tin plasmas for extreme-ultraviolet lithography light sources
  Kentaro Tomita; Yuta Sato; Syouichi Tsukiyama; Toshiaki Eguchi; Kiichiro Uchino; Kouichiro Kouge; Hiroaki Tomuro; Tatsuya Yanagida; Yasunori Wada; Masahito Kunishima; Georg Soumagne; Takeshi Kodama; Hakaru Mizoguchi; Atsushi Sunahara; Katsunobu Nishihara
  SCIENTIFIC REPORTS, 7, 12328, Oct. 2017, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Magnetic reconnection experiment with an external magnetic field by using Gekko-XII laser
  Taichi MORITA; Satoshi MIURA; Masafumi EDAMOTO; Kentaro TOMITA; Yutaro ITADANI; Naoji YAMAMOTO; Shinsuke FUJIOKA; Youichi SAKAWA
  Sep. 2017
  English
• Generation of counter-streaming plasmas for collisionless shock experiment
  Y. Sakawa; T. Ide; T. Morita; K. Tomita; K. Uchino; Y. Kuramitsu; N. Ohnishi; H. Takabe
  HIGH ENERGY DENSITY PHYSICS, 23, 207, 211, Jun. 2017, [Peer-reviewed]
  English, Scientific journal
• Measurements of electron density and electron temperature using laser Thomson scattering in PANTA
  K. Tomita; Y. Sato; N. Bolouki; T. Shiraishi; K. Uchino; Y. Miwa; T. Kobayashi; S. Inagaki
  Plasma and Fusion Research: Regular Articles, 12, 1401018, Mar. 2017, [Peer-reviewed], [Lead author]
  English, Scientific journal

  
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• Spatial and temporal plasma evolutions of magnetic reconnection in laser produced plasmas
  N. Khasanah; C.W. Peng; C.H. Chen; T.Y. Huang; N. Bolouki; T. Moritaka; Y. Hara; H. Shimogawara; T. Sano; Y. Sakawa; Y. Sato; K. Tomita; K. Uchino; S. Matsukiyo; Y. Shoji; S. Tomita; S. Tomiya; R. Yamazaki; M. Koenig; Y. Kuramitsu
  High Energy Density Physics, 23, 15, 19, Feb. 2017, [Peer-reviewed]
  English, Scientific journal
• Development of junction temperature measurement system for blue LED in operation using pulsed-laser Raman scattering
  M. Horiuchi; S. Tsutsumi; Y. Yamagata; K. Tomita; Y. Manabe
  Engineering Sciences Reports, Kyushu University, 38, 2, 1, 7, 九州大学大学院総合理工学府, Feb. 2017, [Peer-reviewed]
  English, Scientific journal, A novel method by using a pulsed-laser Raman scattering technique was employed to estimate junction temperatures of a phosphor-less blue-LED module. Observation of GaN-E_2^H Raman spectra was done successfully and temperature dependent Raman spectra of GaN were detected. This technique was applied to simultaneous estimation of the junction temperatures of the several chips in the phosphor-less blue LED module in operation. It is concluded that this technique would be a useful method for remoteness and simultaneous multipoint measurement of the junction temperature of a LED module in which several chips are integrated.
• Spatial profiles of electron density, electron temperature, average ionic charge, and EUV emission of laser-produced Sn plasmas for EUV lithography
  Y. Sato; K. Tomita; S. Tsukiyama; T. Eguchi; K. Uchino; K. Kouge; H. Tomuro; T. Yanagida; Y. Wada; M. Kunishima; T. Kodama; H. Mizoguchi
  Jpn. J. Appl. Phys., 56, 3, 36201, 36201, Institute of Physics, Jan. 2017, [Peer-reviewed], [Corresponding author]
  English, Scientific journal, Spatial profiles of the electron density (ne), electron temperature (Te), and average ionic charge (Z) of laser-produced Sn plasmas for EUV lithography, whose conversion efficiency (CE) is sufficiently high for practical use, were measured using a collective Thomson scattering (TS) technique. For plasma production, Sn droplets of 26 µm diameter were used as a fuel. First, a picosecond-pulsed laser was used to expand a Sn target. Next, a CO2laser was used to generate plasmas. By changing the injection timing of the picosecond and CO2lasers, three different types of plasmas were generated. The CEs of the three types of plasmas differed, and ranged from 2.8 to 4.0%. Regarding the different plasma conditions, the spatial profiles of ne, Te, and Z clearly differed. However, under all plasma conditions, intense EUV was only observed at a sufficiently high Te(> 25 eV) and in an adequate nerange [10²⁴–(2 × 10²⁵) m⁻³]. These plasma parameters lie in the efficient-EUV light source range, as predicted by simulations.
• Rayleigh Scattering Measurement of Neutral Atom Number Density Downstream of a Hall Thruster under Cold Flow Conditions
  Masataka Iwamoto; Naoji Yamamoto; Taichi Morita; Hideki Nakashima; Kentaro Tomita; Kiichiro Uchino
  TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 60, 5, 327, 330, 2017, [Peer-reviewed]
  English, Scientific journal
• Influence of the gas flow rate on the nonchemical equilibrium N2 arc behavior in a model nozzle circuit breaker
  Yi Wu; Hao Sun; Yasunori Tanaka; Kentaro Tomita; Mingzhe Rong; Fei Yang; Yoshihiko Uesugi; Tatsuo Ishijima; Xiaohua Wang; Ying Feng
  Journal of Physics D: Applied Physics, 49, 42, 425202, Institute of Physics Publishing, 22 Sep. 2016, [Peer-reviewed]
  English, Scientific journal
• Diagnostics of atmospheric-pressure pulsed-dc discharge with metal and liquid anodes by multiple laser-aided methods
  Keiichiro Urabe; Naoki Shirai; Kentaro Tomita; Tsuyoshi Akiyama; Tomoyuki Murakami
  Plasma Sources Science and Technology, 25, 4, 45004, Institute of Physics Publishing, 26 May 2016, [Peer-reviewed]
  English, Scientific journal
• Electrostatic collisionless shock in laser-produced counter-streaming plasmas
  Y. Sakawa; Y. Hara; H. Shimogawara; R. Kumar; Y. Sano; S. Fujioka; K. Tomita; K. Uchino; T. Morita; S. Matsukiyo; R. Yamazak; T. Moritaka; Y. Kuramitsu; R. Crowston; N. Woolsey; B. Albertazzi; M. Koeing; L. Van; Box Som; E. Falize; C. Michaut; P. Barroso; Y. T. Li; X. Pei; H. Wei; J. Y. Zhong; H. Sakagami; H. Takabe
  May 2016
  English
• Radiation Magneto-Hydrodynamics Simulations for Laser- Produced Collisionless Shock Experiment
  A. Ishii; N. Ohnishi; R. Yamazaki; Y. Shoji; S. Tomiya; Y. Sakawa; Y. Hara; H. Shimogawara; S. Matsukiyo; T. Morita; K. Tomita; S. Tanaka; Y. Teraki
  May 2016
  English
• Electron density change of atmospheric-pressure plasmas in helium flow depending on the oxygen/nitrogen ratio of the surrounding atmosphere
  K. Tomita; K. Urabe; N. Shirai; Y. Sato; S. Hassaballa; N. Bolouki; M. Yoneda; T. Shimizu; K. Uchino
  Jpn. J. Appl. Phys., 55, 6, 66101, 66101, Institute of Physics, May 2016, [Peer-reviewed], [Lead author]
  English, Scientific journal, Laser Thomson scattering was applied to an atmospheric-pressure plasma produced in a helium (He) gas flow for measuring the spatial profiles of electron density (ne) and electron temperature (Te). Aside from the He core flow, the shielding gas flow of N2or synthesized air ([Formula: see text]) surrounding the He flow was introduced to evaluate the effect of ambient gas components on the plasma parameters, eliminating the effect of ambient humidity. The neat the discharge center was 2.7 × 10²¹m⁻³for plasma generated with N2/O2shielding gas, 50% higher than that generated with N2shielding.
• Synthesis of photochromic nanoparticles and determination of the mechanism of photochromism
  Shuhei Inoue; Takahiro Kawamoto; Yukihiko Matsumura; Kentaro Tomita; Kiichiro Uchino; Keiji Takata; Hiroshi Kajiyama
  AIP ADVANCES, 6, 5, 55214, May 2016, [Peer-reviewed]
  English, Scientific journal
• Measurement of electron density and electron temperature in decaying arcs containing decomposed gas from polymer
  H. Safwat; K. Tomita
  Engineering Sciences Reports, Kyushu University, 37, 2, 6, 11, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Feb. 2016, [Peer-reviewed]
  English, Scientific journal, Electron density (ne) and electron temperature (Te) in arc discharges generated in the atmospheric air were measured using the laser Thomson scattering (LTS) technique. The arcs were generated using tungsten electrodes with a gap length of 2 mm. At the tip of the cathode electrode, a polymer material-polyoxymethylene (POM) or polytetrafluoroethylene (PTFE)-was inserted to generate the arcs containing the decomposed gas from polymer. LTS results showed that n_e in the arcs varied with the polymer material used. In particular, with POM, the decay speed of n_e was much higher than that with PTFE. The LTS results are qualitatively consistent with the results of previous numerical studies, which indicate that a POM ablation gas can decay the arc conductance more effectively than a PTFE ablation gas.
• Characteristics of extreme ultraviolet emission from high-Z plasmas
  H. Ohashi; T. Higashiguchi; Y. Suzuki; M. Kawasaki; C. Suzuki; K. Tomita; M. Nishikino; S. Fujioka; A. Endo; B. Li; T. Otsuka; P. Dunne; G. O'Sullivan
  8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013), 688, 12079, 2016, [Peer-reviewed]
  English, International conference proceedings
• Collective scattering of an incident monochromatic circularly polarized wave in an unmagnetized non-equilibrium plasma
  S. Matsukiyo; Y. Kuramitsu; K. Tomita
  8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013), 688, 12062, 2016, [Peer-reviewed]
  English, International conference proceedings
• Thomson scattering measurement of a collimated plasma jet generated by a high-power laser system
  T. Ishikawa; Y. Sakawa; T. Morita; Y. Yamaura; Y. Kuramitsu; T. Moritaka; T. Sano; R. Shimoda; K. Tomita; K. Uchino; S. Matsukiyo; A. Mizuta; N. Ohnishi; R. Crowston; N. Woolsey; H. Doyle; G. Gregori; M. Koenig; C. Michaut; A. Pelka; D. Yuan; Y. Li; K. Zhang; J. Zhong; F. Wang; H. Takabe
  8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013), 688, 12098, 2016, [Peer-reviewed]
  English, International conference proceedings
• Spherical shock in the presence of an external magnetic field
  Y. Kuramitsu; S. Matsukiyo; S. Isayama; D. Harada; T. Oyama; R. Fujino; Y. Sakawa; T. Morita; Y. Yamaura; T. Ishikawa; T. Moritaka; T. Sano; K. Tomita; R. Shimoda; Y. Sato; K. Uchino; A. Pelka; R. Crowston; N. Woolsey; G. Gregori; M. Koenig; D. W. Yuan; C. L. Yin; Y. T. Li; K. Zhang; J. Y. Zhong; F. L. Wang; N. Ohnishi; K. Nagamine; H. Yoneda; H. Takabe
  8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013), 688, 12056, 2016, [Peer-reviewed]
  English, International conference proceedings
• Beyond Extreme Ultra Violet (BEUV) Radiation from Spherically symmetrical High-Z plasmas
  Kensuke Yoshida; Shinsuke Fujioka; Takeshi Higashiguchi; Teruyuki Ugomori; Nozomi Tanaka; Masato Kawasaki; Yuhei Suzuki; Chihiro Suzuki; Kentaro Tomita; Ryouichi Hirose; Takeo Eshima; Hayato Ohashi; Masaharu Nishikino; Enda Scally; Hiroaki Nshimura; Hiroshi Azechi; Gerard O'Sullivan
  8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013), 688, 12046, 2016, [Peer-reviewed]
  English, International conference proceedings
• Toward the generation of magnetized collisionless shocks with high-power lasers
  Yoshitaka Shoji; Ryo Yamazaki; Sara Tomita; Yushiro Kawamura; Yutaka Ohira; Satoshi Tomiya; Yoichi Sakawa; Takayoshi Sano; Yukiko Hara; Sarana Kondo; Hiroshi Shimogawara; Shuichi Matsukiyo; Taichi Morita; Kentaro Tomita; Hitoki Yoneda; Kazunori Nagamine; Yasuhiro Kuramitsu; Toseo Moritaka; Naofumi Ohnishi; Takayuki Umeda; Hideaki Takabe
  Plasma and Fusion Research, 11, 2, 3401031, Japan Society of Plasma Science and Nuclear Fusion Research, 2016, [Peer-reviewed]
  English, Scientific journal
• The LTE thermofluid simulation of AR/SF6 gas-blast arcs in a nozzle space in an arc device
  Kosuke Murai; Tomoyuki Nakano; Yasunori Tanaka; Yoshihiko Uesugi; Tatsuo Ishijima; Kentaro Tomita; Katsumi Suzuki; Takanori Iijima; Takeshi Shinkai
  IEEJ Transactions on Power and Energy, 136, 9, 741, 748, Institute of Electrical Engineers of Japan, 2016, [Peer-reviewed]
  English, Scientific journal
• Computational non-chemically equilibrium model on the current zero simulation in a model N2 circuit breaker under the free recovery condition
  Hao Sun; Yasunori Tanaka; Kentaro Tomita; Yi Wu; Mingzhe Rong; Yoshihiko Uesugi; Tatsuo Ishijima
  Journal of Physics D: Applied Physics, 49, 5, 55204, Institute of Physics Publishing, 23 Dec. 2015, [Peer-reviewed]
  English, Scientific journal
• Fundamental investigation technique on gas-blast arc behaviors in decaying and re-ignition processes using power semiconductors
  Yasunori Tanaka; Takahiro Shimizu; Takayasu Fujino; Tomoyuki Nakano; Kentaro Tomita; Katsumi Suzuki
  IEEJ Transactions on Power and Energy, 135, 11, 661, 668, Institute of Electrical Engineers of Japan, 01 Nov. 2015, [Peer-reviewed]
  English, Scientific journal
• Development of a collective Thomson scattering system for laser-produced tin plasmas for extreme-ultraviolet light sources
  K. Tomita; Y. Sato; K. Nishikawa; K. Uchino; T. Yanagida; H. Tomuro; Y. Wada; M. Kunishima; T. Kodama; H. Mizoguchi; A. Sunahara
  Appl. Phys. Express, 8, 12, 126101, 126101, Institute of Physics, Nov. 2015, [Peer-reviewed]
  English, Scientific journal, Spatial profiles of electron density (ne) and electron temperature (Te) of laser-produced Sn plasmas for extreme-ultraviolet (EUV) light sources have been obtained using a new collective Thomson scattering system, which has been optimized for the measurement of the ion feature spectrum. The system has an 18 pm spectral resolution, a 5 ns temporal resolution, a 50 µm spatial resolution, and sufficient stray-light rejection near the probing laser wavelength. With this system, measurements of the laser-produced Sn plasmas in the parameter ranges of 3 × 10²³< ne< 10²⁵m⁻³and 10 < Te< 20 eV have been performed.
• STUDIES OF LASER-PRODUCED ELECTROSTATIC COLLISIONLESS SHOCK USING COLLECTIVE THOMSON SCATTERING ION-TERM MEASUREMENT
  Y. Hara; Y. Sakawa; K. Tomita; Y. Sato; K. Nishikawa; T. Morita; T. Sano; T. Moritaka; H. Takabe
  Sep. 2015
  English
• Thomson scattering diagnostics of SF6 gas-blasted arcs confined by a nozzle under free-recovery conditions
  Kentaro Tomita; Daisuke Gojima; Takahiro Shimizu; Kiichiro Uchino; Tomoyuki Nakano; Yasunori Tanaka; Katsumi Suzuki; Takanori Iijima; Takeshi Shinkai
  Journal of Physics D: Applied Physics, 48, 26, 265201, Institute of Physics Publishing, 08 Jul. 2015, [Peer-reviewed]
  English, Scientific journal
• Development of junction temperature estimation system for light-emitting LED using pulsed-laser Raman scattering
  M. Horiuchi; Y. Yamagata; S. Tsutsumi; K. Tomita; Y. Manabe
  J. Solid State Lighting, 2, 1, 7, Jul. 2015, [Peer-reviewed]
  English, Scientific journal
• Collective Thomson scattering of electrostatic collisionlessshock
  Y. Hara; Y. Sakawa; K. Tomita; Y. Sato; K. Nishikawa; T. Morita; T. Sano; T. Moritaka; H. Takabe
  Apr. 2015
  English
• High Power Laser Experiment of Planar Collisionless Shocks
  M. Nakanotani; S. Matsukiyo; T. Hada; Y. Sakawa; Y. Kuramitsu; T. Morita; K. Tomita; R. Fujino; S. Kubo; T. Sano; T. Moritaka; Y. Hara; R. Yamazaki; H. Takabe
  Apr. 2015
  English
• Density and x-ray emission profile relationships in highly ionized high-Z laser-produced plasmas
  Kensuke Yoshida; Shinsuke Fujioka; Takeshi Higashiguchi; Teruyuki Ugomori; Nozomi Tanaka; Masato Kawasaki; Yuhei Suzuki; Chihiro Suzuki; Kentaro Tomita; Ryoichi Hirose; Takeo Ejima; Hayato Ohashi; Masaharu Nishikino; Atsushi Sunahara; Bowen Li; Padraig Dunne; Gerry O'Sullivan; Tatsuya Yanagida; Hiroshi Azechi; Hiroaki Nishimura
  APPLIED PHYSICS LETTERS, 106, 12, 121109, Mar. 2015, [Peer-reviewed]
  English, Scientific journal
• Development of Thomson Scattering Diagnostics for Cathode-Directed Streamer Discharges in Helium
  N. Bolouki; S. Hassaballa; K. Tomita; K. Uchino
  Engineering sciences reports, Kyushu University, 36, 2, 1, 5, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Feb. 2015, [Peer-reviewed]
  English, Scientific journal, Laser Thomson scattering diagnostics has been developed for the study of the streamer moving toward the cathode in helium near atmospheric pressure. In order to avoid laser perturbation and obtain sufficient intensity of the Thomson scattering signal, two cylindrical lenses were used to optimize the spot size of a probing laser at a focusing point. At a position of 2 mm from the anode (needle electrode), the electron density and electron temperature were successfully measured to be ~ 10^18 m^-3 and ~ 2 eV, respectively, in the initial stage of the primary streamer.
• Evaluation on Current Interruption Ability of CO2 and SF6 using Current and Voltage Application Highly Controlled by Power Semiconductors
  Tomoyuki Nakano; Kosuke Murai; Yasunori Tanaka; Yoshihiko Uesugi; Tatsuo Ishijima; Tatsuro Shiraishi; Takahiro Shimizu; Kentaro Tomita; Katsumi Suzuki; Takeshi Shinkai
  2015 3RD INTERNATIONAL CONFERENCE ON ELECTRIC POWER EQUIPMENT - SWITCHING TECHNOLOGY (ICEPE-ST), 307, 312, 2015, [Peer-reviewed]
  English, International conference proceedings
• The LTF, Simulation on Decaying Arc Plasmas in Various Arc Quenching Gases in a Model Circuit Breaker
  Kosuke Murai; Tomoyuki Nakano; Yasunori Tanaka; Yoshihiko Uesugi; Tatsuo Ishijima; Tatsuro Shiraishi; Takahiro Shimizu; Kentaro Tomita; Katsumi Suzuki; Takayasu Fujino
  2015 3RD INTERNATIONAL CONFERENCE ON ELECTRIC POWER EQUIPMENT - SWITCHING TECHNOLOGY (ICEPE-ST), 146, 151, 2015, [Peer-reviewed]
  English, International conference proceedings
• Temporal evolution of electron density and electron temperature profiles in a non-thermal atmospheric-pressure plasma measured by laser Thomson scattering
  Nima Bolouki; Kentaro Tomita; Safwat Hassaballa; Yukihiko Yamagata; Kiichiro Uchino
  JAPANESE JOURNAL OF APPLIED PHYSICS, 54, 1, 16101, Jan. 2015, [Peer-reviewed]
  English, Scientific journal
• Experimental Investigation on Decaying Arc Behaviors in Alternative Gas Flow using Semiconductors
  Y.,Tanaka; T.,Nakano; K.,Tomita; Fujino,Takayasu; K.,Suzuki
  IEEJ 9th International Workshop on High Voltage Engineering, ED-14-084, SP-14-040, HV-14-09, Nov. 2014
  English, International conference proceedings
• Measurements of Electron Density and Electron Temperature of Arc Discharge Plasmas Containing Metallic Vapors Using Laser Thomson Scattering
  Kentaro Tomita; Shinya Yoshitake; Kiichiro Uchino; Daigo Takenaka; Hiroaki Toda; Masayuki Hikita; Katsumi Suzuki
  ELECTRICAL ENGINEERING IN JAPAN, 188, 4, 1, 8, Sep. 2014, [Peer-reviewed]
  English, Scientific journal
• Experimental study on jet formation and propagation by use of Gekko-XII laser system
  Taichi MORITA; Youichi Sakawa; Kentaro Tomita; Robert Crowston; Ryosuke Fujino; Daisuke Harada; Shogo Isayama; Taishi Ishikawa; Kai Zhang; Michel Koenig; Yasuhiro Kuramitsu; Yutong Li; Shuichi Matsukiyo; Claire Michaut; Toseo Moritaka; Kazuyoshi Nagamine; Tatsuya Oyama; Alexander Pelka; Takayoshi Sano; Yuta Sato; Ryo Shimoda; Tomoya Wadagaki; Nigel Woolsey; Yuta Yamaura; Chuanlei Yin; Hitoki Yoneda; Dawei Yuan; Roman Yurchak; Zhang Zhe; Jiayong Zhong; Hideaki Takabe
  May 2014
  English
• Collisionless shock experiments using large-scale lasers
  Y. Sakawa; T Morita; Y. Yamaura; T. Ishikawa; K. Tomita; R. Crowston; R. Fujino; G. Gregori; C. Huntington; D. Harada; S. Isayama; N. Kugland; Z. Kai; M. Koenig; Y. Kuramitsu; Y- T. Li; S. Matsukiyo; C. Michaut; T. Moritaka; K. Nagamine; T. Oyama; H. S. Park; A. Pelka; B. Remington; T. Sano; Y. Sato; R. Shimoda; A. Spitkovsky; T. Wadagaki; N. Woolsey; C. Yin; H. Yoneda; D. Yuan; R. Yurchak; Z. Zhang; J. Zhong; H. Takabe
  May 2014
  English
• Temperature measurement of junction of light-emitting LED using pulsed-laser Raman scattering
  山形 幸彦; 堀内 誠; 富田 健太郎; 真鍋 由雄
  Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2014, 98, 98, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2014
  集積化，大電流動作された照明用LEDでは，ジャンクション部の温度上昇がもたらす効率及び寿命の著しい低下，動作の不安定化が大きな課題である．そのため照明用LED開発では，発光中LEDのジャンクション部の温度測定を基にしたデバイス全体の放熱設計が最重要である．しかしながら，その直接測定はできておらず，標準的な温度計測技術の開発が切望されている．本研究ではパルスレーザーラマン散乱法を用いて，外乱光に強く，リモート計測可能な発光中LEDの温度計測システムを開発した．今回，GaN-E₂^Hのラマンシフトの温度依存性を観測し，発光中LEDのジャンクション部の温度計測に成功したので報告する．
• Thomson scattering diagnostics of atmospheric plasmas in contact with ionic liquids
  Kentaro Tomita; Kazuhiko Nagai; Takahiro Shimizu; Nima Bolouki; Yukihiko Yamagata; Kiichiro Uchino; Toshiro Kaneko
  Applied Physics Express, 7, 6, 66101, Japan Society of Applied Physics, 2014, [Peer-reviewed]
  English, Scientific journal
• Efficient extreme ultraviolet emission from one-dimensional spherical plasmas produced by multiple lasers
  Kensuke Yoshida; Shinsuke Fujioka; Takeshi Higashiguchi; Teruyuki Ugomori; Nozomi Tanaka; Hayato Ohashi; Masato Kawasaki; Yuhei Suzuki; Chihiro Suzuki; Kentaro Tomita; Ryoichi Hirose; Takeo Ejima; Masaharu Nishikino; Atsushi Sunahara; Enda Scally; Bowen Li; Tatsuya Yanagida; Hiroaki Nishimura; Hiroshi Azechi; Gerry O'Sullivan
  Applied Physics Express, 7, 8, 86202, Japan Society of Applied Physics, 2014, [Peer-reviewed]
  English, Scientific journal
• Thomson scattering diagnostics of decay processes of Ar/SF6 gas-blast arcs confined by a nozzle
  Kentaro Tomita; Daisuke Gojima; Kazuhiko Nagai; Kiichiro Uchino; Ryo Kamimae; Yasunori Tanaka; Katsumi Suzuki; Takanori Iijima; Toshiyuki Uchii; Takeshi Shinkai
  Journal of Physics D: Applied Physics, 46, 38, 382001, 25 Sep. 2013, [Peer-reviewed]
  English, Scientific journal
• Diagnostics of VHF argon plasmas by laser Thomson scattering
  W. Chen; K. Ogiwara; K. Koge; K. Tomita; K. Uchino; Y. Kawai
  Plasma and Fusion Research, 8, 1306114, Sep. 2013, [Peer-reviewed]
  English, Scientific journal
• Investigation of VHF argon plasma at high pressure by balanced power feeding using laser Thomson scattering
  W. Chen; K. Ogiwara; K. Koge; K. Tomita; K. Uchino; Y. Kawai
  Engineering Sciences Reports, Kyushu University, 35, 1, 6, 11, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Sep. 2013, [Peer-reviewed]
  English, Scientific journal, The dependences of the VHF plasma parameters on the gas pressure and power were examined by using the Laser Thomson scattering method, where the VHF plasma was produced in the high pressure region by the balanced power feeding method. It was found that the balanced power feeding method provides a high electron density plasma with low electron temperature at high pressures. This characteristics were confirmed by calculations using a 2-dimensional simulation code.
• Thomson scattering measurement of a shock in laser-produced counter-streaming plasmas
  T. Morita; Y. Sakawa; K. Tomita; T. Ide; Y. Kuramitsu; K. Nishio; K. Nakayama; K. Inoue; T. Moritaka; H. Ide; M. Kuwada; K. Tsubouchi; K. Uchino; H. Takabe
  PHYSICS OF PLASMAS, 20, 9, 92115, Sep. 2013, [Peer-reviewed]
  English, Scientific journal
• Cosmic shocks and magnetic fields: an experiment at GEKKO
  Rob Crowston; Nigel Woolsey; Hugo Doyle; Jena Meinecke; Brian Reville; Youichi Sakawa; Yasuhiro Kuramitsu; Hideaki Takabe; Taichi Morita; Takayoshi Sano; Toseo Moritaka; Yuta Yamaura; Taishi Ishikawa; Hitoki Yoneda; Kazunori Nagamine; Michel Koenig; Alexander Pelka; Jean-Michel Boudenne; Claire Michaut; Kentaro Tomita; Kazuya Inoue; Ryo Shimoda; Jiayong Zhong; Kai Zhang; Feilu Wang; Yutong Li; David Yuan; Francesco Miniati; Gianluca Gregori
  Aug. 2013
  English
• Laboratory astrophysical experiments using Gekko XII laser system
  Y. Sakawa; Y. Kuramitsu; T. Morita; T. Ishikawa; Y. Yamaura; T. Moritaka; T. Sano; H.Takabe; R. Shimoda; K. Tomita; K. Uchino; S. Matsukiyo; A. Mizuta; N. Ohnishi; R. Crowston; N. Woolsey; H. Doyle; G. Gregori; A. Ravasio; A. Pelka; M. Koenig; C. Michaut; D. Yuan; Y. Li; K. Zhang; J. Zhong; F. Wang; A. Spitkovsky; N. L. Kugland; J. S. Ross; H.-S. Park; B. Remington
  Aug. 2013
  English
• Material dependence of shock waves in laser-produced Counter-streaming plasmas
  Y Yamaura; Y. Sakawa; Y Kuramitsu; T Morita; T. Ishikawa; T. Moritaka; T. Sano; R. Shimoda; K. Tomita; K. Uchino; S. Matsukiyo; A. Mizuta; N. Ohnishi; R. Crowston; N. Woolsey; H. Doyle; G. Gregori; A. Ravasio; A. Pelka; M. Koenig; C.Michaut; D. Yuan; Y. Li; K. Zhang; J. Zhong; F. Wang; H.Takabe
  Aug. 2013
  English
• Collective Thomson Scattering diagnostics of Counter-Streaming Plasmas Produced by High-Power Laser Systems
  Kentaro TOMITA; Youichi SAKAWA; Taichi MORITA; Yasuhiro KURAMITSU; Toseo MORITAKA; Ryo SHIMODA; Kiichiro UCHINO; Hideaki TAKABE
  Aug. 2013
  English
• A collective laser Thomson scattering system for diagnostics of laser-produced plasmas for extreme ultraviolet light sources
  K. Tomita; K. Nakayama; K. Inoue; A. Sunahara; K. Uchino
  Appl. Phys. Express, 6, 76101, Jun. 2013, [Peer-reviewed]
  English, Scientific journal
• Measurements of Electron Density and Electron Temperature in a Decay Process of Ar/SF₆ Gas Arc by Using Thomson Scattering
  合嶋 大輔; 永井 和彦; 富田 健太郎; 内野 喜一郎; 田中 康規; 鈴木 克己; 飯島 崇文; 内井 敏之; 新海 健
  Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2013, 451, 451, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2013
  電力用ガス遮断器内アーク現象の定量的把握を目指し、ArガスおよびAr/SF₆混合ガス中において、ガス吹き付けノズル内の長ギャップ電極間で生成されるアークの減衰過程における電子密度・電子温度の時間空間変化を、レーザートムソン散乱法により計測した。放電1回の計測から減衰アークの局所的な情報を得ることができ、SF₆ガスを混入した場合は、Ar(100%)ガスの場合と比較し、アーク半径が小さくなり、かつ電子密度の時間減衰が早くなることが確認された。
• Thomson scattering diagnostics in the plasma of an ion thruster
  N. Yamamoto; Y. Hiraoka; K. Sugita; T. Kurita; K. Tomita; K Uchino; H. Nakashima
  Trans. Jpn. Soc. for Aeronautical and Space Sci., Aerospace Technol. Jpn., 10, 28, Pb79, Pb_83, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, Aug. 2012, [Peer-reviewed]
  English, Scientific journal, In order to validate the grid erosion evaluation code for the lifetime validation of ion thrusters, the electron number density/temperature in the vicinity of a screen gird in a 30 W class microwave discharge ion thruster were measured by means of laser Thomson scattering (LTS) technique. A photon counting method and a triple grating spectrometer were used against a small Thomson scattering signal and a strong stray laser light. Observed Thomson scattering spectrum tells that the electron energy distribution function was Maxwellian. From this spectrum and the Rayleigh scattering calibration using nitrogen gas, electron number density and electron temperature were calculated to be (3.8±0.2)×10¹⁷m^-3 and 6.2±0.1 eV, respectively at incident microwave power of 8 W and krypton mass flow rate of 6.2 μg/s. The ion saturation currents estimated from the LTS measurement are in good agreement with ion beam currents through the screen grid for several conditions. These results show that LTS technique is a useful non-intrusive tool for measuring plasma property in the vicinity of the screen grid.
• Measurement of xenon plasma properties in an ion thruster using laser Thomson scattering technique
  N. Yamamoto; K. Tomita; K. Sugita; T. Kurita; H. Nakashima; K. Uchino
  REVIEW OF SCIENTIFIC INSTRUMENTS, 83, 7, 73106, Jul. 2012, [Peer-reviewed]
  English, Scientific journal
• LABORATORY EXPERIMENTS TO STUDY COLLISIONLESS SHOCKS
  Y. Sakawa; Y. Kuramitsu; T. Morita; T. Ide; K. Nishio; H. Ide; K. Tsubouchi; K. Tomita; K. Uchino; N. Woolsey; C. Murphy; G. Gregori; A. Ravasio; A. Pelka; M. Koenig; A. Spitkovsky; N. L. Kugland; J. S. Ross; H.-S. Park; B. Remington; H.Takabe
  May 2012, [Invited]
  English
• Electron scale magnetic reconnection in a laser produced plasma
  Y. Kuramitsu; T. Moritaka; Y. Sakawa; T. Morita; T. Ide; K. Nishio; C. D. Gregory; J. N. Waugh; B. Loupias; G. Gregori; M. Koenig; N. Woolsey; T. Sano; K. Tomita; K. Uchino; M. Hoshino; H. Takabe
  May 2012
  English
• Two-dimensional Thomson scattering diagnostics of pulsed discharges produced at atmospheric pressure
  K. Tomita; N. Bolouki; H. Shirozono; Y. Yamagata; K. Uchino; K. Takaki
  JOURNAL OF INSTRUMENTATION, 7, C02057, Feb. 2012, [Peer-reviewed]
  English, Scientific journal
• Studies of non-thermel plasmas produced in atmospheric pressure using collective Thomson scattering.
  Nima Bolouki
  Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2012, 508, 508, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2012
  大気圧非熱平衡プラズマは、大気中での生成が可能であることや、ラジカル生成が容易であることなどから、オゾン生成や排ガス処理など、多くの応用例のある有用なプラズマである。しかし、プラズマ形成するパルスマイクロ放電は、微小、短命であるため、プラズマ内部の状態は明らかにされていない。本研究では、大気圧非熱平衡プラズマを形成するひとつのパルスマイクロ放電内の電子密度や電子温度の時間空間分解計測を、レーザートムソン散乱法を用いて行っている。測定対象としたのは、針対半球電極間で生成した容量連結型放電であり、これまでに、再結合過程における電子密度・電子温度の計測を達成した。
• Diagnostics of laser-produced plasmas for EUV light sources using collective Thomson scattering.
  井上 和哉; 下田 諒; 富田 健太郎; 内野 喜一郎
  Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2012, 509, 509, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2012
  半導体集積回路の高集積化は、光リソグラフィ光源の短波長化で実現されてきた。今後更なる高集積化の為に、レーザー生成プラズマ（LPP）方式や放電生成プラズマ（DPP）方式を用いた、波長13.5nmの極端紫外光（EUV）の実用化が期待されているが、発光強度、効率が目標値に達していない。EUVを高効率化するには、プラズマの電子密度・電子温度を制御する必要があるが、これらのEUVプラズマパラメータを診断する方法がないのが現状である。本研究では、レーザー生成EUV光源プラズマにレーザートムソン散乱法を適用し、プラズマの電子密度 （ne）・電子温度 （Te）・平均イオン価数（Z）の計測を確立し、EUV光源実用化へ寄与することを目的としている。
• Measurements of Electron Density and Electron Temperature of Arc Discharges Containing Metallic Vapors.
  Yoshitake Shinya; Tomita Kentaro
  Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2011, 310, 310, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2011
  電力用ガス遮断器は、系統事故時に発生する事故電流等を瞬時に遮断し、系統に接続されている機器の損傷や破壊から保護するために用いられている。遮断器の小型化・高信頼化のためには、アーク放電の基礎特性を把握することが重要である。特に、電流零点近傍における電子密度は、遮断性能を決定づける重要なパラメータである。しかし、アークが消弧する際に、電極などで用いられている金属による蒸気混入がアーク放電の電子密度・電子温度にどう関与するかを実験的に求めた報告例は乏しい。本研究では、大気中アーク放電に対してトムソン散乱測定法を適用し、金属蒸気混入がアーク放電の電子密度・電子温度に及ぼす影響を調査、比較した。
• Spectroscopic Studies of Micro Discharges for Efficient PDP
  Mikami Genichiro; Uchino Kiichiro; Tomita Kentaro; Hasui Yuya; Tanaka Hiroshi
  Record of Joint Conference of Electrical and Electronics Engineers in Kyushu, 2011, 598, 598, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2011
  プラズマディスプレイパネル(PDP)は、微小なセル内の放電により紫外線を発生させ、その紫外線をセル壁面に塗布された蛍光体で可視光に変換し、画像を表示するディスプレイである。これは蛍光灯と同様の発光形態であるがPDPの発光効率は蛍光灯の発光効率に比べ1/10以下と非常に低く、そこに大きな効率改善の余地がある。それに関し、維持電極の幅を従来の電極よりも狭くして放電長を制限することにより高Xe分圧下において効率が良くなることが報告されている。そこで、放電の構造が発光効率にどのように関わるかを明らかにするため、高発光効率PDPマイクロ放電に対し、分光計測を行った。その経過について、報告する。
• Relationship between Ba atom emission and electrode temperature in a low-pressure fluorescent lamp
  Yukihiko Yamagata; Makoto Kai; Sho Naito; Kentaro Tomita; Kiichiro Uchino; Yoshio Manabe
  THIN SOLID FILMS, 518, 13, 3449, 3452, Apr. 2010, [Peer-reviewed]
  English, Scientific journal
• Thomson-Scattering Diagnostics of Plasmas Produced in a Miniature Microwave Discharge Ion Engine
  Tomita Kentaro; Yamamoto Naoji; Yamasaki Naoto; Tsuru Teppei; Uchino Kiichiro; Nakashima Hideki
  JOURNAL OF PROPULSION AND POWER, 26, 2, 381, 384, Mar. 2010, [Peer-reviewed]
  English, Scientific journal
• Plasma Properties in a Miniature Microwave Discharge Ion Thruster
  EZAKI Toru; YAMAMOTO Naoji; TSURU Teppei; KOTANI Yusuke; NAKASHIMA Hideki; YAMASAKI Naoto; TOMITA Kentaro; UCHINO Kiichiro
  TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN, 8, 27, Pb_55, Pb_59, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2010
  English, In order to improve the thrust performance of a 1-mN-class miniature microwave discharge ion thruster, we investigate the dependence of inner plasma properties inside the thruster on operational conditions, krypton mass flow rate, incident microwave power and magnet field strength by laser Thomson scattering (LTS) technique. With an increase in mass flow rate, the electron temperature decreases and the electron number density increases at an incident microwave power of 16 W and the number of magnets of twelve. These results indicate that there is an optimum mass flow rate, which is 0.6 sccm in this condition. The electron number density and temperature increase with incident microwave power and is saturated at 8 W for a mass flow rate of 0.4 sccm and the number of magnets of twelve. With an increase in magnetic field strength, the electron temperature and the electron density suddenly jump from 9.8×10¹⁷ m^-3 and 5.2 eV to 1.7×10¹⁸ m^-3 and 7.3 eV at the number of magnets of thirteen at a mass flow rate of 0.4 sccm and incident microwave power of 16 W.
• Measurements of electron density and temperature in a miniature microwave discharge ion thruster using laser Thomson scattering technique
  N. Yamamoto; K. Tomita; N. Yamasaki; T. Tsuru; T. Ezaki; Y. Kotani; K. Uchino; H. Nakashima
  Plasma Sources Science and Technology, 19, 4, 45009, 2010, [Peer-reviewed]
  English, Scientific journal
• Measurements of distributions of Ba atom density and electrode temperature in low-pressure fluorescent lamp
  M. Naka; M. Kai; Y. Egashira; K. Tomita; Y. Manabe; Y. Yamagata; K. Uchino
  J. Plasma and Fusion Research SERIES, 8, 1308, 1312, Sep. 2009, [Peer-reviewed]
  English, Scientific journal
• Laser Thomson scattering diagnostics of dielectric barrier discharge plasmas
  Y. Sonoda; S. Nishimoto; K. Tomita; S. Hassaballa; Y. Yamagata; K. Uchino
  J. Plasma and Fusion Research SERIES, 8, 696, 699, Sep. 2009, [Peer-reviewed]
  English, Scientific journal
• Collective Thomson scattering diagnostics of EUV plasmas
  K. Tomita; T. Kagawa; K. Uchino; S. Katsuki; H. Akiyama
  J. Plasma and Fusion Research SERIES, 8, 488, 491, Sep. 2009, [Peer-reviewed]
  English, Scientific journal
• Laser Thomson scattering and optical emission studies of striated PDP micro-discharge plasmas
  S Hassaballa; Y Sonoda; K Tomita; YK Kim; K Uchino
  JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 13, 8, 639, 645, Aug. 2005, [Peer-reviewed]
  English, Scientific journal
• Laser Thomson scattering measurements of electron density and temperature profiles of a striated plasma in a plasma display panel (PDP)-like discharge
  S Hassaballa; K Tomita; YK Kim; K Uchino; H Hatanaka; YM Kim; CH Park; K Muraoka
  JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 44, 12-15, L442, L444, 2005, [Peer-reviewed]
  English, Scientific journal
• Laser Thomson Scattering and Optical Emission Studies of PDP
  Hassaballa Safwat; Tomita Kentaro; Kim Young Kee; Uchino Kiichiro
  九州大学大学院総合理工学報告, 26, 3, 327, 332, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Dec. 2004
  English, Properties of a plasma display panel (PDP) like discharge were examined by emission and laser Thomson scattering (LTS) measurements. Emission measurements were performed using an intensified CCD camera. By varying several external parameters such as amplitude of the input voltage, gas composition and pressure, the influence of these parameters on the discharge behavior was studied. Results of emission measurements showed that they were in good agreement with similar emission measurements on real PDP cells. LTS measurements were performed for the discharge at a pressure of 100 Torr. The results yielded precise profiles of electron density and electron temperature of the striated PDP-like plasma for the first time.
• Two-dimensional structure of PDP micro-discharge plasmas obtained using laser Thomson scattering
  S Hassaballa; M Yakushiji; YK Kim; K Tomita; K Uchino; K Muraoka
  IEEE TRANSACTIONS ON PLASMA SCIENCE, 32, 1, 127, 134, Feb. 2004, [Peer-reviewed]
  English, Scientific journal
• Thomson scattering diagnostics of glow discharge plasmas produced in Raman active gases
  S Narishige; S Kitamura; S Sakemi; K Tomita; K Uchino; K Muraoka; T Sakoda
  JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 41, 11A, L1259, L1262, Nov. 2002, [Peer-reviewed]
  English, Scientific journal

• 半導体リソグラフィー用EUV-BEUV光源のイオンデブリの価数分離エネルギースペクトル—Charge-separated ionic debris spectra in EUV-BEUV sources for semiconductor lithography—フォトニクス・ワークショップ in 九州 : 福岡
  東口 武史; 中山 勇冬; 新沼 大登; 久米 真樹; 杉浦 使; 森田 大樹; 富田 健太郎; 砂原 淳; 難波 慎一; 江島 丈雄, レーザー学会研究会報告 = Reports the on topical meeting of the Laser Society of Japan, RTM22, 26-31, 11, 16, 05 Sep. 2022
  [吹田] : レーザー学会研究委員会, Japanese
• レーザー生成プラズマ極端紫外光源から発生する高速イオンのエネルギースペクトル—Energy spectra of fast ions from a laser-produced plasma EUV source—放電・プラズマ・パルスパワー研究会・放電・プラズマ・パルスパワー一般
  東口 武史; 中山 勇冬; 新沼 大登; 久米 真樹; 森田 大樹; 砂原 淳; 富田 健太郎; 江 偉華; 難波 慎一; 江島 丈雄, 電気学会研究会資料. EPP = The papers of technical meeting, IEE Japan / [放電・プラズマ・パルスパワー研究会] [編], 2022, 60-65, 1, 6, 20 May 2022
  東京 : 電気学会, Japanese
• Energy spectra of fast ions from a laser-produced plasma EUV source
  東口武史; 中山勇冬; 新沼大登; 久米真樹; 森田大樹; 砂原淳; 富田健太郎; JIANG Weihua; 難波慎一; 江島丈雄, 電気学会研究会資料(Web), EPP-22-060-065, 2022
• Charge-separated ionic debris spectra in EUV-BEUV sources for semiconductor lithography
  東口武史; 中山勇冬; 新沼大登; 久米真樹; 杉浦使; 森田大樹; 富田健太郎; 砂原淳; 難波慎一; 江島丈雄, レーザー学会研究会報告, 567th, 2022
• Experiments of generation of collisionless shocks propagating into magnetized plasma
  山崎了; 田中周太; 相原研人; 佐藤雄飛; 塩田珠里; 高田敦也; 松井啓一郎; 佐野孝好; 太田雅人; 江頭俊輔; 倉本織羽乃; 松本雄志郎; 蔵満康浩; 南卓海; 境健太郎; 西本貴博; 岩崎滉; 松清修一; 森田太智; 松尾涼人; 児島拓仁; 枝本雅史; 富田健太郎; 竹崎太智; 小口拓哉; 星野真弘; 大平豊; 梅田隆行; 石井彩子; 大西直文; 冨田沙羅; 坂和洋一, 衝撃波シンポジウム講演論文集(CD-ROM), 2021, 2022
• レーザーアブレーションプラズマが駆動する磁気リコネクション研究(2019A-MORITA)
  森田太智; 高木麻理子; 西岡裕輝; 枝本雅史; 坂和洋一; 富田健太郎; 佐野孝好; 蔵満康浩; 山崎了; 田中周太; 松清修一; 大平豊; 太田雅人; 江頭俊輔; 泉智大; 境健太郎; 角地真; 瀬井柊人; 石坂夏槻; 杉山慧; 樋口琢己; 村上洋大, 大阪大学レーザー科学研究所共同利用・共同研究成果報告書(Web), 2019, 2020
• 高出力レーザーを用いた磁気リコネクション実験における局所プラズマ・磁場計測
  森田太智; 枝本雅史; 西岡裕輝; 佐野孝好; 太田雅人; 江頭俊輔; 泉智大; 松清修一; 堀江由実; 樋口琢海; 山崎了; 田中周太; 遠田裕史; 宮田親; 角地真; 瀬井柊人; 石坂夏規; 冨田沙羅; 河村璃子; 杉山慧; 鈴木大介; 高山紗良; 富田健太郎; 蔵満康浩; 境健太郎; 南卓海; 坂和洋一, 日本物理学会講演概要集(CD-ROM), 74, 1, ROMBUNNO.17aK309‐10, 22 Mar. 2019
  Japanese
• レーザー生成対向プラズマ中における磁気リコネクション
  森田太智; 長島圭祐; 枝本雅史; 板谷佑太朗; 佐野孝好; KUMAR R; 太田雅人; 江頭俊輔; 山崎了; 田中周太; 冨谷聡志; 遠田裕史; 宮田親; 角地真; 瀬井柊人; 石坂夏規; 冨田沙羅; 富田健太郎; 蔵満康浩; 松清修一; 坂和洋一, 日本物理学会講演概要集(CD-ROM), 73, 2, ROMBUNNO.9aC102‐6, 21 Sep. 2018
  Japanese
• 高出力レーザーと外部磁場を用いた磁気リコネクション実験
  森田太智; 枝本雅史; 富田健太郎; 板谷佑太朗; 松清修一; 佐野孝好; 山崎了; 坂和洋一, 日本物理学会講演概要集(CD-ROM), 73, 1, ROMBUNNO.25aK609‐3, 23 Mar. 2018
  Japanese
• 磁気リコネクション実験
  坂和洋一; 江頭俊輔; 太田雅人; KUMAR Rajesh; LAW K. F. F; 南卓海; 藤田泰彦; 上林大介; 堺健太郎; 佐野孝好; 森田太智; BOLOUKI Nima; 金崎真聡; 福田祐仁; 松尾一輝; MORACE A; 藤岡慎介; 余語覚文; 乗松孝好; 羽原英明; 蔵満康浩; 尾崎典雅; 富田健太郎; 松清修一; 星野真弘; 山崎了; 田中周太; 米田仁紀; 森高外征雄; KOENIG Michel; CASNER Alexis; MICHAUT Claire, 大阪大学レーザー科学研究所共同利用・共同研究成果報告書(CD-ROM), 2017, ROMBUNNO.1‐17, Mar. 2018
  Japanese
• プラズマ衝撃波のマルチスケール構造の精密測定
  松清修一; 香月のどか; 初山凌介; 堀江由実; 坂和洋一; 佐野孝好; 森田太智; 富田健太郎; 枝本雅史; 太田雅人; 江頭俊輔; KUMAR Rajesh; 山崎了; BOLOUKI Nima; 蔵満康浩; 冨田沙羅; 田中周太, 大阪大学レーザー科学研究所共同利用・共同研究成果報告書(CD-ROM), 2017, ROMBUNNO.1‐3, Mar. 2018
  Japanese
• 磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験
  山崎了; 冨谷聡志; 遠田裕史; 宮田親; 安部大晟; 石坂夏規; 角地真; 瀬井柊人; 冨田沙羅; 坂和洋一; 佐野孝好; 江頭俊輔; 太田雅人; KUMAR Rajesh; 蔵満康浩; 松清修一; 森田太智; 富田健太郎; 枝本雅史; 小沼杏奈; 浅井晴貴; 飯田浩祐; 米田仁紀; 田中周太; 大西直文; 井上剛志; 梅田隆行; 高部英明; 星野真弘; 大平豊; 石井彩子; 寺木悠人, 大阪大学レーザー科学研究所共同利用・共同研究成果報告書(CD-ROM), 2017, ROMBUNNO.1‐1, Mar. 2018
  Japanese
• 高出力レーザーを用いた磁気リコネクション実験
  森田太智; 長島圭祐; 枝本雅史; 板谷佑太朗; 佐野孝好; KUMAR Rajesh; 太田雅人; 江頭俊輔; 山崎了; 田中周太; 冨谷聡志; 遠田裕史; 宮田親; 角地真; 瀬井柊人; 石坂夏槻; 冨田沙羅; 富田健太郎; 蔵満康浩; 松清修一; 坂和洋一, プラズマ・核融合学会年会(Web), 35th, ROMBUNNO.S7‐3 (WEB ONLY), 2018
  Japanese
• Fundamental studies on switching arcs -Experimental and numerical approaches
  Yasunori Tanaka; Tomoyuki Nakano; Sun Hao; Kentaro Tomita; Yuki Inada; Akiko Kumada; Kunihiko Hidaka; Takayasu Fujino; Katsumi Suzuki; Takeshi Shinkai, ICEPE-ST 2017 - 4th International Conference on Electric Power Equipment- Switching Technology, 2017-, 1, 10, 12 Dec. 2017
  Institute of Electrical and Electronics Engineers Inc., English
• Fundamental study on re-ignition process for CO2-blast arcs in a model circuit breaker using synthetic tests highly controlled by power semiconductors
  Tomoyuki Nakano; Yu Tabata; Yasunori Tanaka; Yoshihiko Uesugi; Tatsuo Ishijima; Kentaro Tomita; Yuki Inada; Katsumi Suzuki; Takeshi Shinkai, ICEPE-ST 2017 - 4th International Conference on Electric Power Equipment- Switching Technology, 2017-, 263, 267, 12 Dec. 2017
  Institute of Electrical and Electronics Engineers Inc., English
• パワー半導体スイッチを利用した合成試験によるCO₂ガスのアーク消弧能力評価 (放電 静止器 開閉保護 合同研究会 アークプラズマ・電気接点とその応用)
  中野 智之; 田畑 裕; 田中 康規; 上杉 喜彦; 石島 達夫; 富田 健太郎; 稲田 優貴; 鈴木 克巳; 新海 健, 電気学会研究会資料. ED = The papers of technical meeting on electrical discharges, IEE Japan, 2017, 68, 11, 16, 19 Jul. 2017
  電気学会, Japanese
• Measurements of Electron Density and Electron Temperature of Atmospheric Pressure Plasmas Using Thomson Scattering
  富田 健太郎; 内野 喜一郎, プラズマ・核融合学会誌 = Journal of plasma and fusion research, 93, 5, 232, 235, May 2017
  プラズマ・核融合学会編集委員会, Japanese
• 磁気リコネクション実験
  坂和洋一; 下河原浩志; KUMAR Rajesh; 松尾一輝; 佐野孝好; 藤岡慎介; 乗松孝好; 森田太智; 板谷佑太朗; 富田健太郎; 築山晶一; 深田来夢; 内野喜一郎; 松清修一; 香月のどか; 星野真弘; 山崎了; 正治圭崇; 冨田沙羅; 冨谷聡志; 小林瑛史; 野上雅弘; 遠田裕史; 宮田親; 木坂将大; 田中周太; 小沼杏奈; 米田仁紀; 森高外征雄; 高嶺愛子; KOENIG Michel; ALBERTAZZI Bruno; MICHEL Thibault; RIGON Gabriel; CASNER Alexis; MICHAUT Claire; BARROSO Patrice, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2016, 20‐21, Mar. 2017
  Japanese
• 磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験
  山崎了; 正治圭崇; 冨谷聡志; 遠田裕史; 宮田親; 大平豊; 冨田沙羅; 小林瑛史; 野上雅弘; 木坂将大; 坂和洋一; 佐野孝好; KUMAR Rajesh; 下河原浩志; 松清修一; 森田太智; 富田健太郎; 香月のどか; 小沼杏奈; 米田仁紀; 田中周太; 大西直文; 石井彩子; 蔵満康浩; 梅田隆行; 高部英明; 星野真弘; 森高外征雄; 高峰愛子; 寺木悠人; 井上剛志, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2016, 9‐10, Mar. 2017
  Japanese
• プラズマ衝撃波のマルチスケール構造の精密測定
  松清修一; 香月のどか; 坂和洋一; 佐野孝好; 下河原浩志; KUMAR Rajesh; 富田健太郎; 森田太智; 山崎了; 正治圭崇; 冨谷聡志; 遠田裕史; 宮田親; 冨田沙羅; 小林瑛史; 野上雅弘; 木坂将大; 森高外征雄; 蔵満康浩; 羽田亨, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2016, 14‐15, Mar. 2017
  Japanese
• Non-equilibrium studies in switching arc plasmas in Japan
  Y. Tanaka; K. Tomita; Y. Inada; A. Kumada; K. Hidaka; T. Fujino; K. Suzuki; T. Shinkaig, 22nd Symposium on Physics of Switching Arc, 2017-, 225, 233, 2017
  Brno University of Technology, English
• 高出力レーザーを用いたプラズマ中衝撃波における磁場増幅モデル実験とその解析 II
  下河原浩志; 坂和洋一; RAJESH Kumar; 森田太智; 富田健太郎; 松清修一; 山崎了; 蔵満康浩; 佐野孝好; 大西直文; 水田晃; 高部英明; 森高外征雄, 日本物理学会講演概要集(CD-ROM), 71, 2, ROMBUNNO.16aKC‐4, 704, 23 Sep. 2016
  

  我々は、高出力レーザーを用いた宇宙プラズマ現象の模擬実験を行う事で、宇宙空間での計測の難しい微視的な物理を明らかにすることを目的として研究を行っている。宇宙空間において超新星残骸(SNR)などで観測される無衝突衝撃波は宇宙線加速や磁場増幅に重要な役割を果たすことが、天体観測から明らかになっている。SNRでの磁場増幅機構の1つとして、非一様な媒質中に無衝突衝撃波が伝搬し、励起されたリヒトマイヤー・メシュコフ不安定性（RMI）による磁場増幅が、理論研究やシミュレーションから示されている。今回は、RMIのモデル実験を行い、プラズマの温度・密度の時間発展の解析を進めた。

  , The Physical Society of Japan, Japanese
• 流動型液体電極を有する大気圧プラズマの特性評価と金属電極放電との比較
  白井直機; 白井直機; 占部継一郎; 富田健太郎; 秋山毅志; 村上朝之, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 77th, ROMBUNNO.16p‐P2‐4, 01 Sep. 2016
  Japanese
• Arc Re-ignition Processes by Application of Quasi-Transient Recovery Voltage in Different Gas Flow in a Nozzle
  中野 智之; 村井 康佑; 田中 康規; 上杉 喜彦; 石島 達夫; 白石 竜郎; 清水 陽大; 富田 健太郎; 鈴木 克巳; 新海 健, 電気学会研究会資料. SP = The papers of technical meeting on switching and protecting engineering, IEE Japan, 2016, 1, 89, 94, 13 Jun. 2016
  電気学会, Japanese
• 大型レーザー生成プラズマ中衝撃波における磁場増幅のモデル実験
  下河原浩志; 坂和洋一; 原由紀子; KUMAR Rajesh; 森田太智; 富田健太郎; 松清修一; 山崎了; 蔵満康浩; 森高外征雄; 佐野孝好; 大西直文; 水田晃; 高部英明, 日本物理学会講演概要集(CD-ROM), 71, 1, ROMBUNNO.22AAE‐12, 976, 22 Mar. 2016
  The Physical Society of Japan (JPS), Japanese
• プラズマ衝撃波のマルチスケール構造の精密測定
  松清修一; 潮崎幸太; 香月のどか; 椎葉星哉; 坂和洋一; 佐野孝好; 原由希子; 下河原浩志; 富田健太郎; 森田太智; 山崎了; 蔵満康浩; 森高外征雄; 高部英明; 羽田亨, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2015, 22, 23, Mar. 2016
  Japanese
• 無衝突衝撃波研究のための新規協同トムソン散乱システムの開発
  富田健太郎; 坂和洋一; 蔵満康浩; 佐藤祐太; 原由希子; 森田太智; 松清修一; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2015, 16, 17, Mar. 2016
  Japanese
• 磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験
  山崎了; 正治圭崇; 冨谷聡志; 冨田沙羅; 大平豊; 坂和洋一; 佐野孝好; 原由希子; 下河原浩志; 松清修一; 森田太智; 富田健太郎; 米田仁紀; 蔵満康浩; 森高外征雄; 大西直文; 石井彩子; 梅田隆行; 高部英明; 田中周太; 寺木悠人; 井上剛志, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2015, 26, 27, Mar. 2016
  Japanese
• 超音速対向プラズマ流による無衝突衝撃波の生成
  坂和洋一; 原由希子; 下河原浩志; KUMAR Rajesh; 佐野孝好; 藤岡慎介; 乗松孝好; 森田太智; 齋藤直哉; 川島諒祐; 枝本雅史; 三浦智之; 板谷佑太朗; 富田健太郎; 佐藤裕太; 川原拓也; BOLOUKI Nima; 内野喜一郎; 松清修一; 潮崎幸太; 椎葉星哉; 香月のどか; 蔵満康浩; 森高外征雄; PENG Cheng‐Wei; HUANG Tzu‐Yao; CHEN Chia‐Heng; 山崎了; 正治圭崇; 冨田沙羅; 冨谷聡志; 大平豊; 前田はるか; 田中周太; 寺木悠人; 小沼杏奈; 米田仁紀; KOENIG Michel; ALBERTAZZI Bruno; FALIZE Emeric, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2015, 20, 21, Mar. 2016
  Japanese
• 磁化プラズマ中を伝播する無衝突衝撃波の生成実験:2015年度の実験結果
  山崎了; 正治圭崇; 冨谷聡志; 冨田沙羅; 大平豊; 坂和洋一; 佐野孝好; 原由希子; 下河原浩志; 松清修一; 森田太智; 富田健太郎; 高部英明; 米田仁紀; 田中周太; 寺木悠人, 日本天文学会年会講演予稿集, 2016, 273, 20 Feb. 2016
  Japanese
• The LTE Thermofluid Simulation of Decaying Arcs in Various Gas Flow in a Nozzle Space and Experimental Study
  村井 康佑; 中野 智之; 田中 康規; 上杉 喜彦; 石島 達夫; 白石 竜朗; 清水 陽大; 富田 健太郎; 鈴木 克巳; 藤野 貴康, 電気学会研究会資料. SA, 2015, 56, 31, 36, 08 Jul. 2015
  電気学会, Japanese
• Numerical Simulations of Arc Properties in a Nozzle using Various Alternative Gases
  垂石 早紀; 矢田部 優樹; 藤野 貴康; 田中 康規; 富田 健太郎; 鈴木 克己, 電気学会研究会資料. SA, 2015, 56, 25, 30, 08 Jul. 2015
  電気学会, Japanese
• Fundamental Evaluation on Current Interruption Ability of Various Gases using quasi-TRV Application Controlled by Power Semiconductors
  中野 智之; 田中 康規; 上杉 喜彦; 石島 達夫; 白石 竜郎; 清水 陽大; 富田 健太郎; 鈴木 克己, 電気学会研究会資料. SA, 2015, 56, 79, 84, 08 Jul. 2015
  電気学会, Japanese
• 大型レーザーによって生成された無衝突衝撃波の協同トムソン散乱計測
  原由希子; 坂和洋一; 富田健太郎; 佐藤裕太; 西川和孝; 森田太智; 佐野孝好; 高部英明, 日本物理学会講演概要集(CD-ROM), 70, 1, ROMBUNNO.23PBH-5, 892, 24 Mar. 2015
  The Physical Society of Japan (JPS), Japanese
• 激光XII号レーザーを用いたEUV‐BEUV光源プラズマデータベースの構築
  大橋隼人; 藤岡慎介; 松隈啓; 吉田健祐; 細田達矢; 東口武史; 笹沼淳史; 原広行; 富田健太郎; 佐藤祐太; 江島丈雄; 鈴木千尋; 砂原淳; 錦野将元, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2014, 11, 12, Mar. 2015
  Japanese
• 磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験
  山崎了; 正治圭崇; 河村有志郎; 冨田沙羅; 大平豊; 坂和洋一; 高部英明; 佐野孝好; 森高外征雄; 原由希子; 近藤さらな; 松清修一; 森田太智; 富田健太郎; 米田仁紀; 長嶺和慶; 蔵満康浩; 大西直文; 梅田隆行, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2014, 21, 22, Mar. 2015
  Japanese
• 協同的トムソン散乱法による無衝突衝撃波の研究
  富田健太郎; 坂和洋一; 蔵満康浩; 西川和孝; 佐藤祐太; 原由希子; 森田太智; 松清修一; 中野谷賢; 藤野亮佑; 内野喜一郎; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2014, 41, 42, Mar. 2015
  Japanese
• レーザー生成プラズマと外部磁場を用いた磁場リコネクションの研究
  森高外征雄; 坂和洋一; 佐野孝好; 原由希子; 近藤さらな; 蔵満康浩; 森田太智; 松清修一; 富田健太郎; 藤野亮佑; 山崎了; 正治圭崇; 冨田沙羅; 河村有志郎; CROWSTON R; 長嶺和慶; 米田仁紀; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2014, 37, 38, Mar. 2015
  Japanese
• 超音速対向プラズマ流による無衝突衝撃波の生成
  坂和洋一; 原由希子; 近藤さらな; 森田太智; 蔵満康浩; 佐野孝好; 森高外征雄; 西川和孝; 佐藤裕太; 富田健太郎; 内野喜一郎; 中野谷賢; 藤野亮佑; 久保聡一朗; 松清修一; 齋藤直哉; 正治圭崇; 河村有志郎; 冨田沙羅; 山崎了; 長峰和慶; 米田仁紀; 大西直文; ZHU Baojun; LI Yanfei; LI Yutong; PEI Xiaoxing; WEI Huigang; ZHONG J; CHU Hsu‐Hsin; CROWSTON R; WOOSLEY N; KOENIG M; BARROSO Patrice; MICHAUT C; ZHANG Z; 乗松孝好; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2014, 39, 40, Mar. 2015
  Japanese
• Laboratory astrophysics experiments using large-scale laser systems: Collisionless shock generation
  坂和洋一; PARK H.-S.; GREGORI G.; SPITKOVSKY A.; FIUZA F.; HUNTINGTON C.; ROSS J. S.; RYUTOV D. D.; POLLOCK B. B.; REMINGTON B.; WEBER S. V.; TURNBULL D. P.; MEINECKE J.; LEVY M. C.; ZYLSTRA A. B.; LI C. K.; RINDERKNECHT H.; ZYLSTRA A.; PETRASSO R.; KUGLAND N. L.; DRAKE R. P.; KURANZ C.; FROULA D. H.; REGAN S.; ROSENBERG M.; LAMB D.; TZEFERACOS P.; WOOLSEY N.; KOENIG M.; 原由希子; 下河原浩志; 森田太智; 富田健太郎; 松清修一; 山崎了; 蔵満康浩; 森高外征雄; 加藤恒彦; 佐野孝好; 高部英明, プラズマ・核融合学会年会(Web), 32nd, 2015
• 協同的トムソン散乱法を用いたSF₆ガス吹付けアークの減衰過程研究 (放電 静止器 開閉保護合同研究会・アークプラズマ・電気接点とその応用)
  富田 健太郎; 清水 陽大; 内野 喜一郎; 中野 智之; 田中 康規; 鈴木 克己; 飯島 崇文; 内井 敏之; 新海 健, 電気学会研究会資料. SA, 2014, 45, 7, 11, 09 Jun. 2014
  電気学会, Japanese
• A Fundamental Investigation on a Decaying Gas-Blast Arcs in a Nozzle using Power Semiconductors
  田中 康規; 中野 智之; 石島 達夫; 上杉 喜彦; 清水 陽大; 富田 健太郎; 内野 喜一郎; 鈴木 克巳; 飯島 崇文; 新海 健, 電気学会研究会資料. SA, 2014, 45, 1, 6, 09 Jun. 2014
  電気学会, Japanese
• 高出力レーザー生成無衝突衝撃波のトムソン散乱計測
  坂和洋一; 山浦裕太; 森田太智; 石川大志; 和田垣智也; 佐野孝好; 森高外征雄; ZHANG Z; 佐藤裕太; 下田諒; 富田健太郎; 内野喜一郎; 諌山翔伍; 藤野亮佑; 大山達也; 原田大輔; 松清修一; 長峰和慶; 米田仁紀; 大西直文; 水田晃; YUAN D., LI Y; ZHANG K; ZHONG J; CROWSTON R; WOOLSEY N; PELKA A; KOENIG M; YURCHAK R; MICHAUT C; BARROSO P; 蔵満康浩; 高部英明, 日本物理学会講演概要集, 69, 1, 272, 272, 05 Mar. 2014
  The Physical Society of Japan (JPS), Japanese
• 球対称プラズマを用いたBEUV光源データベースの構築
  吉田健祐; 藤岡慎介; 東口武史; 鵜篭照之; 田中のぞみ; 川崎将人; 鈴木悠平; 大橋隼人; 鈴木千尋; 富田健太郎; 廣瀬僚一; 江島丈雄; 錦野将元; SCALLY Enda; O’SULLIVAN Gerard; 西村博明; 疇地宏, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 61st, ROMBUNNO.18P-F1-12, 03 Mar. 2014
  Japanese
• 激光XII号レーザーを用いたEUV‐BEUV光源プラズマデータベースの構築
  東口武史; 藤岡慎介; 鵜篭輝之; 吉田健祐; 田中のぞみ; 鈴木悠平; 川崎将人; 大橋隼人; 江島丈雄; 廣瀬僚一; 鈴木千尋; 富田健太郎; 砂原淳; 錦野将元, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2013, 47, 48, Mar. 2014
  Japanese
• 協同的トムソン散乱法による無衝突衝撃波の研究
  富田健太郎; 坂和洋一; 蔵満康浩; 森田太智; 下田諒, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2013, 9, 10, Mar. 2014
  Japanese
• レーザー生成プラズマと外部磁場を用いた磁気リコネクションの研究
  森高外征雄; 坂和洋一; 蔵満康浩; 森田太智; 石川大志; 山浦佑太; 富田健太郎; 佐野孝好; 和田垣智也; 松清修一; 山崎了; 星野真弘; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2013, 29, 30, Mar. 2014
  Japanese
• レーザー生成プラズマ中における磁場の計測
  森田太智; 坂和洋一; 坂和洋一; 石川大志; 山浦祐太; 佐野孝好; 森高外征雄; 富田健太郎; 下田諒; 佐藤裕太; 松清修一; 諌山翔伍; 原田大輔; 大山達也; 藤野亮佑; 蔵満康浩; 米田仁紀; 長嶺和慶; KOENIG Michel; YURCHAK Roman; MICHAUT Claire; WOOLSEY Nigel; CROWSTON Robert; PELKA Alexander; LI Yutong; YUAN Dawei; YIN Chuanlei; ZHONG Jiayong; ZHANG Kai; 高部英明; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2013, 23, 24, Mar. 2014
  Japanese
• 超音速対向プラズマ流による無衝突衝撃波の生成
  坂和洋一; 森田太智; 山浦裕太; 石川大志; 和田垣智也; 蔵満康浩; 佐野孝好; 森高外征雄; 下田諒; 佐藤裕太; 富田健太郎; 内野喜一郎; 諌山翔伍; 藤野亮佑; 大山達也; 原田大輔; 松清修一; 長峰和慶; 米田仁紀; 大西直文; 水田晃; ZHANG Z; 乗松孝好; YIN C; YUAN D., LI Y; ZHANG K; ZHONG J; CROWSTON R; WOOLSEY N; PELKA A; YURCHAK R; KOENIG M; BOUDENNE J; MICHAUT C; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2013, 27, 28, Mar. 2014
  Japanese
• 大型レーザーを用いた無衝突衝撃波生成実験
  坂和洋一; 蔵満康浩; 森田太智; 富田健太郎; 高部英明, レーザー学会研究会報告, 456th, 31, 37, 08 Jan. 2014
  Japanese
• 球対称プラズマを用いたBEUV光源データベースの構築
  吉田健祐; 藤岡慎介; 東口武史; 鵜篭照之; 田中のぞみ; 川崎将人; 鈴木悠平; 鈴木千尋; 富田健太郎; 廣瀬僚一; 江島丈雄; 大橋隼人; 錦野将元; SCALLY Enda; O’SULLIVAN Gerard; 西村博明; 疇地宏, レーザー学会研究会報告, 450th, 19, 24, 22 Oct. 2013
  Japanese
• Diagnostics of High-Z Light Source Plasmas
  TOMITA Kentaro; UCHINO Kiichiro, プラズマ・核融合学会誌, 89, 10, 664, 668, Oct. 2013
  多価電離プラズマ光源の一つである,レーザー生成方式極端紫外(EUV)光源プラズマのための,協同的トムソン散乱計測システムの開発を行っている.システム構築のために,まずはレーザー生成炭素プラズマのイオン項スペクトルを計測することで,その電子密度,電子温度,イオン温度,平均イオン価数の局所値を求めた.計測用レーザーにはNd:YAGレーザー第2高調波(波長532nm)を使用した.この時,イオン項のスペクトル幅は0.3nm程度と予想される.イオン項スペクトル計測のために,高い波長分解能と迷光除去性能を有する,差分散型トリプル分光器を作製した.本計測システムを用いて,EUV光源プラズマと同様の電子密度(10^<24>-10^<25>m^<-3>),電子温度(30-50eV)の炭素プラズマに対して,トムソン散乱計測が可能なことを示した.炭素プラズマの計測結果を基に,実際のEUV光源で使用されるスズプラズマのための新たな分光器の開発を行っている., プラズマ・核融合学会, Japanese
• Collective Thomson scattering measurements of Laser-produced Sn plasmas for EUV light sources
  SHIMODA Ryo; NISHIKAWA Kazutaka; TOMITA Kentaro; UCHINO Kiichiro, 電気学会研究会資料. PST, プラズマ研究会, 2013, 104, 21, 24, 05 Sep. 2013
  Japanese
• 球対称BEUV放射プラズマの電子密度計測
  鵜篭照之; 藤岡慎介; 吉田健祐; 田中のぞみ; 西村博明; 東口武史; 鈴木悠平; 川崎将人; 江島丈雄; 廣瀬僚一; 富田健太郎; 鈴木千尋; 大橋隼人; 錦野将元; 疇地宏, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 74th, ROMBUNNO.18P-A13-12, 31 Aug. 2013
  Japanese
• 球対称ガドリニウムプラズマからのB‐EUV放射特性とスペクトル特性
  吉田健祐; 藤岡慎介; 東口武史; 鵜篭照之; 田中のぞみ; 川崎将人; 鈴木悠平; 鈴木千尋; 富田健太郎; 廣瀬僚一; 江島丈雄; 大橋隼人; 錦野将元; 西村博明; 疇地宏, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 74th, ROMBUNNO.18P-A13-13, 31 Aug. 2013
  Japanese
• Results of laser experiments for collisionless shocks
  Sakawa Y.; Kuramitsu Y.; Morita T.; Yamaura Y.; Ishikawa T.; Sano Y.; Moritaka T.; Inoue K.; Shimoda R.; Tomita K.; Uchino K.; Nagamine K.; Yoneda H.; Matsukiyo S.; Onishi N.; Mizuta A.; Norimatsu T.; Nishida A.; Kodama; Yuan D.; Li Y.; Zhang K.; Wang F.; Zhong J.; Crowston R.; Woolsey N.; Doyle H.; Gregori G.; Pelka A.; Koenig M.; Boudenne J.; Michaut C.; Spitkovsky A.; Kugland N.L.; Ross J.S.; Park H.-S.; Remington B.; Takabe H., Meeting abstracts of the Physical Society of Japan, 68, 2, 202, 202, 26 Aug. 2013
  The Physical Society of Japan (JPS), Japanese
• 無衝突衝撃波のレーザー模擬実験の成果
  坂和洋一; 蔵満康浩; 森田太智; 山浦裕太; 石川大志; 佐野孝好; 森高外征雄; 井上和哉; 下田諒; 富田健太郎; 内野喜一郎; 長峰和慶; 米田仁紀; 松清修一; 大西直文; 水田晃; 乗松孝好; 西田明憲; 兒玉了祐; YUAN D., LI Y; ZHANG K; WANG F; ZHONG J; CROWSTON R; WOOLSEY N; DOYLE H; GREGORI G; PELKA A; KOENIG M; BOUDENNE J; MICHAUT C; SPITKOVSKY A; KUGLAND N.L; ROSS J.S; PARK H.‐S; REMINGTON B; 高部英明, 日本物理学会講演概要集, 68, 2, 121, 26 Aug. 2013
  Japanese
• 高出力レーザー生成プラズマ及び衝撃波のターゲット材質依存性について
  山浦佑太; 坂和洋一; 蔵満康浩; 森田太智; 石川大志; 森高外征雄; 佐野孝好; 下田亮; 富田健太郎; 内野喜一郎; 松清修一; 水田晃; 大西直文; CROWSTON R; WOOLSEY N; DOYLE H; GREGORI G; RAVASIO A; PELKA A; KOENIG M; MICHAUT C; YUAN D., LI Y; ZHANG K; ZHONG J; WANG F; 高部英明, 日本物理学会講演概要集, 68, 2, 211, 211, 26 Aug. 2013
  The Physical Society of Japan (JPS), Japanese
• 高出力レーザーを用いたプラズマジェットのコリメーション現象の研究
  石川大志; 坂和洋一; 蔵満康浩; 森田太智; 山浦祐太; 森高外征雄; 佐藤孝好; 下田亮; 富田健太郎; 内野喜一郎; 松清修一; 水田晃; 大西直文; CROWSTON R; WOOLSEY N; DOYLC H; GREGORI G; RAVASIO A; PELKA A; KOENIG M; MICHAUT C; YUAN D., LI Y; ZHANG K; ZHONG J; WANG F; 高部英明, 日本物理学会講演概要集, 68, 2, 211, 211, 26 Aug. 2013
  The Physical Society of Japan (JPS), Japanese
• Observation of Dynamic Behavior of Ar/SF_6 Gas-Blast Arc Confined by a Nozzle under Free Recovery Condition using a High Speed Video Camera
  TANAKA Yasunori; KAMIMAE Ryo; ISHIJIMA Tatsuo; UESUGI Yoshihiko; TOMITA Kentaro; UCHINO Kiichiro; SUZUKI Katsumi; IIJIMA Takanori; SHINKAI Takeshi, 電気学会研究会資料. ED, 放電研究会, 2013, 64, 23, 28, 24 Jun. 2013
  Japanese
• Measurements of Electron Density and Electron Temperature in a Decay Process of Ar/SF_6 Gas-Blasted Arc Confined by a Nozzle by Using Collective Thomson Scattering
  TOMITA Kentaro; GOJIMA Daisuke; NAGAI Kazuhiko; UCHINO Kiichiro; KAMIMAE Ryo; TANAKA Yasunori; SUZUKI Katsumi, 電気学会研究会資料. ED, 放電研究会, 2013, 64, 47, 51, 24 Jun. 2013
  Japanese
• 29pEA-1 Experimental study on high Mach number collisionless shocks
  Kuramitsu Y.; Sakawa Y.; Morita T.; Moritaka T.; Sano T.; Tomita K.; Uchino K.; Matsukiyo S.; Mizuta A.; Ohnishi N.; Takabe H., Meeting abstracts of the Physical Society of Japan, 68, 1, 307, 307, 26 Mar. 2013
  The Physical Society of Japan (JPS), Japanese
• 29pEA-2 Thomson scattering measurement of collisionless shocks
  Sakawa Y.; Kuramitsu Y.; Morita T.; Yamaura Y.; Ishikawa T.; Tomita K.; Inoue K.; Shimoda R.; Uchino K.; Moritaka T.; Sano T.; Takabe H., Meeting abstracts of the Physical Society of Japan, 68, 1, 307, 307, 26 Mar. 2013
  The Physical Society of Japan (JPS), Japanese
• 高マッハ数無衝突衝撃波の実験的研究
  蔵満康浩; 坂和洋一; 森田太智; 森高外征雄; 佐野孝好; 富田健太郎; 内野喜一郎; 松清修一; 水田晃; 大西直文; 高部英明, 日本物理学会講演概要集, 68, 1, 307, 05 Mar. 2013
  Japanese
• 無衝突衝撃波のトムソン散乱計測
  坂和洋一; 蔵満康浩; 森田太智; 山浦佑太; 石川大志; 富田健太郎; 井上和哉; 下田諒; 内野喜一郎; 森高外征雄; 佐野孝好; 高部英明, 日本物理学会講演概要集, 68, 1, 307, 05 Mar. 2013
  Japanese
• 協同的トムソン散乱法による無衝突衝撃波の研究
  富田健太郎; 坂和洋一; 蔵満康浩; 森田太智; 井上和哉; 井手張良; 坪内邦男, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2012, 11, 12, Mar. 2013
  Japanese
• 高出力レーザーによって生成された高速対向プラズマ流による無衝突衝撃波の生成
  坂和洋一; 蔵満康浩; 森田太智; 山浦裕太; 石川大志; 佐野孝好; 森高外征雄; 井上和哉; 下田諒; 富田健太郎; 内野喜一郎; 長峰和慶; 米田仁紀; 松清修一; 大西直文; 水田晃; 乗松孝好; 西田明憲; 兒玉了祐; YUAN D., LI Y; ZHANG K; WANG F; ZHONG J; CROWSTON R; WOOSLEY N; DOYLE H; GREGORI G; PELKA A; KOENIG M; BOUDENNE J; MICHAUT C; 高部英明, 大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書, 2012, 24, 25, Mar. 2013
  Japanese
• Measurements of electron density and electron temperature of arc discharge plasmas containing metallic vapors using laser thomson scattering
  Kentaro Tomita; Shinya Yoshitake; Kiichiro Uchino; Daigo Takenaka; Hiroaki Toda; Masayuki Hikita; Katsumi Suzuki, IEEJ Transactions on Fundamentals and Materials, 133, 9, 458, 464, 2013
  Japanese
• 電子の運動論効果による磁気リコネクション
  蔵満康浩; 坂和洋一; 森田太智; 森高外征雄; 富田健太郎; 内野喜一郎; 星野真弘; 高部英明, 日本物理学会講演概要集, 67, 2, 206, 24 Aug. 2012
  Japanese
• Studies of Arc Discharges in Gas Circuit Breakers using Collective Thomson Scattering
  TOMITA Kentaro; GOJIMA Daisuke; UCHINO Kiichiro; HIKITA Masayuki; TAKENAKA Daigo; TODA Hiroaki; SUZUKI Katsumi; UCHII Toshiyuki, 電気学会研究会資料. SA, 静止器研究会, 2012, 54, 53, 58, 25 Jun. 2012
  Japanese
• 26pYC-9 High Mach-number shock-shock interaction in laser-produced plaamas
  Morita Taichi; Nihida Akinori; Norimatsu Takayoshi; Tomita Kentaro; Uchino Kiichiro; Namiki Tomonori; Yoneda Hitoki; Takabe Hideaki; Sakawa Youichi; Kuramitsu Yasuhiro; Ide Takao; Nishio Kento; Kuwada Misa; Ide Harunaga; Tsubouchi Kunio; Shimazaki Seiichi, Meeting Abstracts of the Physical Society of Japan, 67, 0, 276, 276, 2012
  The Physical Society of Japan, Japanese
• Thomson Scattering Measurements of Arc Discharge Plasmas Containing Metallic Vapor
  TAKENAKA Daigo; HIKITA Masayuki; YOSHITAKE Shinya; TOMITA Kentarou; UCHINO Kiichirou; TODA Hiroaki; SUZUKI Katsumi, 電気学会研究会資料. SP, 開閉保護研究会, 2011, 19, 173, 177, 10 Nov. 2011
  Japanese
• Collective Thomson Scattering Diagnostics of Laser Produced Plasmas
  TOMITA K.; UCHINO K., レーザー学会研究会報告 = Reports on the Topical meeting of the Laser Society of Japan, 418, 51, 54, 12 Sep. 2011
  Japanese
• Measurements of electron density and electron temperature of arc discharges containing metallic vapors using Thomson scattering
  TAKENAKA Daigo; TODA Hiroaki; HIKITA Masayuki; YOSHITAKE Shinya; TOMITA Kentarou; UCHINO Kiichirou; SUZUKI Katsumi, 電気学会研究会資料. ED, 放電研究会, 2011, 55, 19, 23, 04 Jul. 2011
  Japanese
• Thomson scattering diagnostics of micro-plasmas for plasma display panel
  Kiichiro Uchino; Yasushi Sonoda; Kentaro Tomita, Proceedings of International Meeting on Information Display, 275, 276, 01 Dec. 2010
• Thomson Scattering Diagnostics of Discharge Plasmas
  Kiichiro Uchino; Kentaro Tomita, Industrial Plasma Technology: Applications from Environmental to Energy Technologies, 385, 397, 07 Oct. 2010
  Wiley-VCH, English
• Measurement of Electron Temperature and Electronic Density of the Atmosphere Arc with Collective Thomson Scattering Measuring System
  TAKENAKA Daigo; TODA Hiroaki; HIKITA Masayuki; SUZUKI Katsumi; TOMITA Kentarou; UCHINO Kiichirou, 電気学会研究会資料. ED, 放電研究会, 2010, 34, 15, 18, 28 Jun. 2010
  Japanese
• Thomson scattering diagnostics of high pressure plasmas and plasma disturbances by lasers
  Kentaro Tomita; Safwat Hassaballa; Kiichiro Uchino, IEEJ Transactions on Fundamentals and Materials, 130, 12, 8, 1104, 2010
  Japanese
• Thomson Scattering with Measuring the Conductance Decaying Process System of Arc Plasma in Gas Circuit Breaker
  TAKENAKA Daigo; HARADA Katuhiko; OHTSUKA Shinya; HIKITA Masayuki; TODA Hiroaki; IKEDA Hisatoshi; SUZUKI Katsumi; UCHINO Kiichirou; TOMITA Kentarou, 電気学会研究会資料. ED, 放電研究会, 2009, 152, 19, 23, 19 Nov. 2009
  Japanese
• Dependence of electron temperature and number density on magnetic field strength in an ion thruster by laser Thomson scattering
  江崎 徹; 小谷優介; 鶴哲平; 山本直嗣; 中島秀紀; 富田健太郎; 山崎尚人; 内野喜一郎, プラズマ応用科学, 17, 1, 21, 26, 2009
  プラズマ応用科学会, Japanese
• Plasma property measurement in a miniature microwave discharge ion thruster by laser Thomson scattering
  Naoji Yamamoto; Shmya Kondo; Teppei Tsuru; Hideki Nakashima; Amane Majima; Naoto Yamasaki; Kentaro Tomita; Knchiro Uchino, 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 01 Dec. 2008
• Diagnostics of PDP Micro-discharge Plasmas Using Infrared Laser Thomson Scattering
  SONODA Yasushi; AKUNE Akihiko; TOMITA Kentaro; SAFWAT Hassaballa; UCHINO Kiichiro; ISHII Keiji; HIRANO Yoshikuni; MURAKAMI Yukio, IEICE technical report, 107, 453, 117, 120, 17 Jan. 2008
  In order to avoid laser perturbations for Xe containing discharges, the laser Thomson scattering (LTS) system having an infrared laser at a wavelength of 1064nm as a light source has been developed. The basic behavior of electrons in the Ne/Xe discharges was investigated by using the infrared LTS system. Furthermore, it was demonstrated that the measurement of the electron energy distribution function was possible up to the electron energy corresponding to the excitation energy of the Xe atom., The Institute of Electronics, Information and Communication Engineers, Japanese
• Diagnostics of PDP micro-discharge plasmas using infrared laser Thomson scattering
  園田 靖; 阿久根 明彦; 富田 健太郎, ITE technical report, 32, 4, 117, 120, Jan. 2008
  映像情報メディア学会, Japanese
• Diagnostics of PDP micro-discharge plasmas using infrared laser thomson scattering system
  Y. Sonoda; A. Akune; K. Tomita; S. Hassaballa; K. Uchino; K. Ishii; Y. Hirano; Y. Murakami, IDW '07 - Proceedings of the 14th International Display Workshops, 2, 861, 864, 01 Dec. 2007
• Laser Scattering Diagnostics of Discharge Plasmas
  UCHINO K.; TOMITA K.; SONODA Y., レーザー学会研究会報告 = Reports on the Topical meeting of the Laser Society of Japan, 365, 43, 47, 14 Sep. 2007
  Japanese
• Characterization of Z-pinch plasmas for EUV light sources
  S. Katsuki; H. Imamura; S. Akiyoshi; T. Namihira; T. Sakugawa; H. Akiyama; K. Tomita; K. Uchino, Digest of Technical Papers-IEEE International Pulsed Power Conference, 864, 867, 2007
  English

• Increment of EUV radiation and reduction of ion energy of laser-produced Sn EUV-light-source plasmas by controlling initial plasma structure using multiple prepulse laser irradiations
  Kentaro Tomita; Yiming Pan; Hirokazu Hosoda; Shinji Nagai; Atsushi Sunahara; Katsunobu Nishihara
  2025 EUVL and Source Workshop, 24 Jun. 2025, English, Invited oral presentation
  24 Jun. 2025 - 26 Jun. 2025, [Invited]
• プラズマの理解に基づくEUV発光制御 – EUV発生に適したレーザー条件とは?
  富田健太郎
  OPICセミナー2025, 26 Mar. 2025, Japanese, Invited oral presentation
  26 Mar. 2025 - 28 Mar. 2025, [Invited]
• EUV光源の温度・密度・流れ場観測と 高出力化に向けた展望
  富田 健太郎
  最先端ナノエレクトロニクス技術調査専門委員会, 29 Nov. 2024, Japanese, Invited oral presentation
  29 Nov. 2024, [Invited]
• 産業応用プラズマを対象としたトムソン散乱計測の実際 – 分光器設計からスペクトル解析まで
  富田 健太郎
  第５回・可知化センシングユニットセミナー, 17 Jul. 2024, Japanese, Invited oral presentation
  17 Jul. 2024, [Invited]
• 分光学的手法によるプラズマの電子状態計測－EUV露光光源用プラズマを題材に－
  富田 健太郎
  第34回 プラズマエレクトロニクス講習会 ～プラズマプロセスの基礎と先端応用技術～, 17 Nov. 2023, Japanese, Invited oral presentation
  17 Nov. 2023, [Invited]
• Measurements of electron density, electron temperature, and velocity field in laser-produced EUV source plasmas using collective Thomson scattering
  Kentaro Tomita; Yiming Pan; Atsushi Sunahara; Katsunobu Nishihara
  The 7th Asia-Pacific Conference on Plasma Physics (AAPPS-DPP2023), 15 Nov. 2023, Invited oral presentation
  12 Nov. 2023 - 17 Nov. 2023, [Invited]
• EUVプラズマの診断や制御のための計測技術
  富田 健太郎
  情報機構セミナー, 31 May 2023, Japanese, Invited oral presentation
  [Invited]
• トムソン散乱法を用いたレーザー生成EUV光源内部の流れ場計測 -流れが発光効率改善に与える影響を考える
  富田; 健太郎; 潘; 奕明; 砂原; 淳; 西原 功修
  一般社団法人レーザー学会学術講演会第43回年次大会, 20 Jan. 2023, Japanese, Invited oral presentation
  18 Jan. 2023 - 20 Jan. 2023, [Invited]
• レーザートムソン散乱による軟X線，EUV光源用プラズマ源の時空間分解計測
  富田 健太郎
  第39回 プラズマ・核融合学会 年会, 22 Nov. 2022, Japanese, Invited oral presentation
  22 Nov. 2022 - 25 Nov. 2022
• Observation of Plasma Inflow in Laser-Produced Sn EUV Sources Contributing to Increment of EUV Light Output Using Thomson Scattering Technique
  Kentaro Tomita
  2022 Source Workshop, 25 Oct. 2022, Invited oral presentation
  22 Oct. 2022 - 27 Oct. 2022, [Invited]
• Observation of two-dimensional plasma flows toward higher temperature regions in laser produced tin plasmas for extreme ultraviolet (EUV) light sources
  Kentaro Tomita; Yiming Pan; Atsushi Sunahara; Katsunobu Nishihara
  14th International Symposium on Advanced Plasma Science and its Applications for Nitrides and Nanomaterials (ISPlasma2022), 07 Mar. 2022, Invited oral presentation
  06 Mar. 2022 - 10 Mar. 2022, [Invited]
• Thomson scattering studies of atmospheric-air streamer discharges and Extreme-ultraviolet (EUV) light sources
  Kentaro Tomita
  The 39th Symposium on Plasma Processing (SPP-39), 24 Jan. 2022, Invited oral presentation
  24 Jan. 2022 - 26 Jan. 2022, [Invited]
• Recent progress of laser Thomson scattering studies for industrial plasmas -Measurements of EEDF of air-streamer discharge and 2D velocity field in laser produced EUV sources-
  Kentaro Tomita
  The 12th Asia-Pacific International Symposium on the Basics and Applications of Plasma Technology (APSPT-12), 10 Dec. 2021, Invited oral presentation
  09 Dec. 2021 - 11 Dec. 2021, [Invited]
• Recent Studies of Industrial Plasmas using Laser Scattering
  Kentaro Tomita
  日本物理学会 2021年秋季大会, 22 Sep. 2021, Japanese, Invited oral presentation
  20 Sep. 2021 - 23 Sep. 2021, [Invited]
• Thomson scattering diagnostics of EUV source plasmas and EUV induced hydrogen plasmas
  Kentaro Tomita
  EUV source workshop2020, 05 Nov. 2020, Invited oral presentation
  [Invited]
• Thomson scattering diagnostics of a streamer discharge in atmospheric-pressure air and laser-produced plasmas for light sources
  Kentaro Tomita
  Gaseous Electronics Conference (GEC), 06 Oct. 2020, Invited oral presentation
  [Invited]
• Observation of the whole Thomson scattering spectrum of laser produced plasma for EUV and soft X-ray light sources
  K. Tomita; F. Ito; J. Hotta; K. Uchino
  The 19th LASER AIDED PLASMA DIAGNOSTICS 2019, 22 Sep. 2019, English, Invited oral presentation
  [Invited], [International presentation]

  
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• [プラズマエレクトロニクス賞受賞記念講演] 極端紫外および軟X線光源用多価電離プラズマの協同的トムソン散乱計測 - 点光源を空間分解計測する -
  Kentaro Tomita
  応用物理学会、2018年9月19日、名古屋国際会議場、愛知, 01 Mar. 2019, English, Invited oral presentation
  [Invited], [International presentation]
• レーザープラズマX線源のプラズマパラメータ計測
  Kentaro Tomita
  物理学会年次大会、領域2シンポジウム、レーザープラズマX線源の物理と応用、九州大学、福岡、2019年、3月15日, 01 Mar. 2019, English, Invited oral presentation
  [Invited], [International presentation]
• In-situ plasma diagnostics using optically-trapped fine particles
  Kentaro Tomita
  International symposium on Frontier of Nano-Materials Based on Advanced Plasma Technologies, MRS-J,Annual meeting, C3-I18-005, 18th, Nov., Kitakyushu, Fukuoka, Japan, 01 Dec. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• optical diagnostics of nano-second pulsed discharges produced in atmosphere
  Kentaro Tomita
  Lecture at the Department of Materials Sciend and Engineering, Feng Chia University, Taiwan, Nov. 17th, 2018, Taichung, Taiwan, 01 Nov. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• Two-dimensional Profiles of Electron Density and Temperature in Laser-produced Sn Plasmas for Extreme-ultraviolet (EUV) light sources
  Kentaro Tomita
  2nd Asia-Pacific Conference on Plasma Physics, Nov. 14th,11.2018, Kanazawa, Japan, 01 Nov. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• Studies of EUV light source plasmas using laser Thomson scattering
  Kentaro Tomita
  Plasma Engineering Forum of MRS-T, Nov. 17th, 2018, Taichung, Taiwan, 01 Nov. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• Introduction to plasma diagnostics”,
  Kentaro Tomita
  Workshop for the Applications of Plasma Technology, Ming Chi University of Technology, New Taipei City, Taiwan, 29th Oct. 2018., 01 Oct. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• 先端計測で明らかとなったEUV露光光源用プラズマの詳細構造 - 中空様密度構造が実現する4%変換効率 -
  Kentaro Tomita
  日本学術振興会第153委員会研究会 テーマ：『高密度プラズマの計測技術 〜高密度プラズマの物理現象の見える化技術〜』, 2018年1月18日, 01 Jan. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• Diagnostics of extreme-ultraviolet (EUV) light source plasmas for next generation semiconductor lithography
  Kentaro Tomita
  International Symposium in 27th Annual Meeting of MRS-J, Yokohama, Japan, 2017.12, 01 Dec. 2017, English, Invited oral presentation
  [Invited], [International presentation]
• Two-dimensional electron density and temperature profiles of EUV light sources with 4.0% CE
  Kentaro Tomita
  International workshop on EUV and Soft X-ray sources (2017 source workshop), Dublin, Ireland, 2017.11, 01 Nov. 2017, English, Invited oral presentation
  [Invited], [International presentation]
• Two-dimensional profiles of electron density and temperature of laser-produced tin microplasmas for extreme-ultraviolet lithography light sources
  Kentaro Tomita
  International Workshop on Microplasmas (IWM2017), Garmisch-Partenkirchen, Germany, 2017.6, 01 Jun. 2017, English, Invited oral presentation
  [Invited], [International presentation]
• レーザー計測で切り拓く実験室宇宙物理研究
  Kentaro Tomita
  レーザー学会学術講演会第37回年次大会, 徳島, 2017年1月9日, 01 Jan. 2017, English, Invited oral presentation
  [Invited], [International presentation]
• Collective Thomson scattering diagnostics for industrial plasmas
  Kentaro Tomita
  Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congress (APPC-AIP), Brisbane, Australia, 2016.12, 01 Dec. 2016, English, Invited oral presentation
  [Invited], [International presentation]
• Correlation of Fundamental Plasma Parameters with EUV Emission Profiles of Laser-produced Sn Plasmas for EUV Lithography Light Sources
  Kentaro Tomita
  International Workshop on EUV and Soft X-Ray Sources (2016 Source Workshop), Amsterdam, The Netherlands, 2016.11, 01 Nov. 2016, English, Invited oral presentation
  [Invited], [International presentation]
• プラズマ診断・計測
  Kentaro Tomita
  第10回プラズマエレクトロニクスインキュベーションホール、2016年8月31日、国立中央青少年交流の家、静岡県, 01 Aug. 2016, English, Invited oral presentation
  [Invited], [International presentation]
• Diagnostics of laser-produced EUV light source plasmas using collective Thomson scattering
  Kentaro Tomita
  The 13th Asia-Pacific Conference on Plasma Science and Technology (APCPST), Shanghai, China, 2016.5, 01 May 2016, English, Invited oral presentation
  [Invited], [International presentation]
• 高気圧プラズマへのトムソン散乱法の適用とレーザー擾乱の検討
  Kentaro Tomita
  日本物理学会第71回年次大会（2016年）, 領域2シンポジウム「プラズマ診断のための能動的光計測の新展開」, 宮城, 2016年3月, 01 Mar. 2016, English, Invited oral presentation
  [Invited], [International presentation]
• 協同的トムソン散乱によるレーザー生成EUV光源プラズマの電子密度・電子温度・イオン価数計測
  Kentaro Tomita
  第36回レーザー学会年次大会, 愛知, 2016.1, 01 Jan. 2016, English, Invited oral presentation
  [Invited], [International presentation]
• Studies of Laser-produced Tin plasmas for EUV Light Sources using Collective Thomson Scattering
  Kentaro Tomita
  2015 International workshop on EUV and Soft X-ray sources, Dublin, Ireland, 2015.11, 01 Nov. 2015, English, Invited oral presentation
  [Invited], [International presentation]
• Collective Thomson scattering diagnostics of laser-produced plasmas with moderate temperature
  Kentaro Tomita
  17th International Symposium on Laser-Aided Plasma Diagnostics, Sapporo, Hokkaido, Japan, 2015.10, 01 Oct. 2015, English, Invited oral presentation
  [Invited], [International presentation]
• Thomson scattering diagnostics of atmospheric pressure plasmas - Pulsed filament discharges and plasma jets -
  Kentaro Tomita
  68th GEC / ICRP-9, Honolulu, Hawaii, USA, 2015.10, 01 Oct. 2015, English, Invited oral presentation
  [Invited], [International presentation]
• 激光 XII 号レーザーへの協同トムソン散乱法の適用
  Kentaro Tomita
  レーザー研シンポジウム2015−平成26年度共同研究成果報告会−, 大阪大学吹田キャンパス銀杏会館、2015.4.8-9, 01 Mar. 2015, English, Invited oral presentation
  [Invited], [International presentation]
• 高気圧プラズマのレーザー散乱計測
  Kentaro Tomita
  静電気学会計測研究委員会、広島国際大学 呉キャンパス 1号館3階1305教室、2014年9月9日, 01 Sep. 2014, English, Invited oral presentation
  [Invited], [International presentation]
• 協同的トムソン散乱法による大気圧減衰アークの電子密度・電子温度測定
  Kentaro Tomita
  電気学会北陸支部シンポジウム, 石川, 2013.3.6., 01 Mar. 2013, English, Invited oral presentation
  [Invited], [International presentation]
• Thomson scattering diagnostics of atmospheric pressure plasmas generated with ionic liquid electrode
  Kentaro Tomita
  The 6th International Conference on Plasma Nano Technology and Science, Gifu, Japan, 2013.2, 01 Feb. 2013, English, Invited oral presentation
  [Invited], [International presentation]
• トムソン散乱法を用いた大気圧フィラメント放電の研究
  Kentaro Tomita
  応用物理学会第11回プラズマエレクトロニクス新領域研究会「光・レーザーによるプラズマ計測の最前線」, 大分, 2012.11, 01 Nov. 2012, English, Invited oral presentation
  [Invited], [International presentation]
• 協同的トムソン散乱によるレーザー生成EUVプラズマ診断
  Kentaro Tomita
  レーザー学会専門委員会「レーザー駆動XUV〜X線の産業応用専門委員会」, 東京, 2012.6.20., 01 Jun. 2012, English, Invited oral presentation
  [Invited], [International presentation]
• レーザー散乱法を用いたプラズマ計測
  Kentaro Tomita
  第8回日本真空学会スパッタリングおよびプラズマプロセスに関する技術交流会, 東京, 2011.12, 01 Dec. 2011, English, Invited oral presentation
  [Invited], [International presentation]
• Thomson scattering diagnostics of a pulsed discharge produced at around atmospheric pressure
  Kentaro Tomita
  15th International symposium of laser-aided plasma diagnostics, Jeju, Korea, 2011.10, 01 Oct. 2011, English, Invited oral presentation
  [Invited], [International presentation]
• Studies of Pulsed Filament Discharges Produced in Near-Atmospheric Pressure Using Laser Thomson Scattering
  Kentaro Tomita
  the 12th international workshop on advanced plasma precessing and diagnostics, Fukuoka, Japan, 2011.1, 01 Jan. 2011, English, Invited oral presentation
  [Invited], [International presentation]
• 「プラズマエレクトロニクスへの要望と期待 ?若手研究者からの声?」第6回プラズマ応用技術の将来ビジョン研究会「プラズマエレクトロニクスの将来研究」
  Kentaro Tomita
  応用物理学会プラズマエレクトロニクス分科会, 東京, 2006.2.6., 01 Feb. 2006, English, Invited oral presentation
  [Invited], [International presentation]

• レーザープロセス工学特論, 2024年, 修士課程, 工学院
• レーザープロセス工学特論, 2024年, 修士課程, 工学院
• レーザープロセス工学特論, 2024年, 博士後期課程, 工学院
• レーザープロセス工学特論, 2024年, 博士後期課程, 工学院
• 応用電子工学, 2024年, 学士課程, 工学部
• プラズマ物理, 2024年, 学士課程, 工学部
• 電磁気学, 2024年, 学士課程, 工学部
• 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育

• プラズマの電子電界加速から活性種生成・反応に至る一連のプロセス解明
  科学研究費助成事業
  Apr. 2024 - Mar. 2029
  小野 亮; 富田 健太郎; 中川 雄介; 稲田 優貴
  日本学術振興会, 学術変革領域研究(A), 東京大学, 24H02248
• 大気圧直流グロー放電生成時に観測される発光の自己組織化メカニズムの解明
  科学研究費助成事業
  01 Apr. 2023 - 31 Mar. 2027
  白井 直機; 佐々木 浩一; 富田 健太郎
  大気圧中で直流電圧駆動の放電プラズマを生成するとある条件において、陽極表面上で自己組織化された発光が観測されるが、その生成因子を実験的アプローチにより調査した。自己組織化パターン形成には、負性ガスである酸素の有無が重要であること、数学的に自己組織化形状が得られる反応拡散系ではある反応物質の密度が増減しながら拡散して模様を形成することを考慮すると、プラズマによるパターン形成は負イオンの有無と電界による輸送が重要であると予想される。2023年度はレーザー光脱離法による負イオン種の同定、レーザー誘起蛍光法による窒素イオン密度の計測、OHラジカルの密度分布・回転温度の計測パターン構造の外部電場制御を行った。その結果パターン構造が生じた際にOH-等の負イオンは確かに観測されるものの、液体陽極の場合と金属陽極の場合で観測される負イオン種の比率が異なっていてもパターン構造が観測されることから負イオンは直接的な生成因子でないことが示唆された。一方、レーザー誘起蛍光法によるOHラジカルの密度ならびに回転温度の空間分布の結果からパターン形成が観測されているときに放電プラズマ領域の温度が高くなっていることが観測された。これは温度の上昇によりプラズマ領域の密度分布が低くなっていることを示唆している。計算シミュレーションや低気圧環境でのプラズマにおいては希ガスのみでも
  パターン形成が得られていることから、大気圧直流放電によるパターン形成においても負イオンよりも温度上昇による密度の低下或いは、空間密度分布の変化が重要である可能性が見出された。
  日本学術振興会, 基盤研究(B), 北海道大学, 23K26083
• 大気圧直流グロー放電生成時に観測される発光の自己組織化メカニズムの解明
  科学研究費助成事業
  01 Apr. 2023 - 31 Mar. 2027
  白井 直機; 佐々木 浩一; 富田 健太郎
  日本学術振興会, 基盤研究(B), 北海道大学, 23H01388
• Collisionless shock generation and particle acceleration using power laser
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2026
  坂和 洋一; 松清 修一; 森田 太智; 富田 健太郎; Morace Alessio; 竹崎 太智; 福田 祐仁; 山崎 了
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Osaka University, 22H00119
• Studies for radiation and paticle motion controls beased on velocity fields measurements of laser-produced plasmas
  Grants-in-Aid for Scientific Research
  Apr. 2023 - Mar. 2026
  富田 健太郎; 砂原 淳; 佐々木 明; 西原 功修
  本研究の目的は、先駆的計測技術（２次元速度場計測が可能な協同トムソン散乱など）を駆使し、レーザー生成プラズマ（laser produced plasma:LPP）の速度場計測を通じ、プラズマ中の流動現象の理解を図ることを主な目的の一つとしている。また、LPPを短波長光源として利用することを前提として、プラズマの流れを制御することで、光出力の制御が可能であるかを、学術的な問いとして掲げている。上記目的や問いに対する答えを得るために、初年度の２０２３年度は、主に２次元速度場計測の堅牢生（ロバスト性）の確認実験を行った。２次元空間速度場の計測は、協同的トムソン散乱計測で得られるイオン項スペクトルのドップラーシフトを用いて行う。ただし、速度場の確定には速度の大きさと方向の２項目を特定しなければならないのに対して、スペクトルのドップラーシフトは、プラズマのドリフト速度方向と計測レーザーの波数ベクトル、そして散乱光の波数ベクトルで決定され、波長シフトという１項目しか情報がない。最終的に、散乱光を２方向から計測、もしくは計測レーザーの波数ベクトルを２種類用意し、２次元空間速度場を得ることができるが、より簡単な計測システムとして、プラズマの軸対称性を仮定することで、どこまで速度場が確定できるかを確認した。プラズマ生成用レーザーに対して垂直に平板ターゲット（炭素）を置き、プラズマを生成した。この場合、プラズマ生成用レーザーを中心軸とした、軸対称のプラズマ移動を仮定することができる。この仮定が成立するとき、プラズマ生成用レーザーから４５度異なる１方向から散乱光を取得する実験系であっても、速度の大きさと方向の２種類を特定できる。実際に実験を行った結果、速度の大きさ、方向の両方について、適切な精度で決定できることが分かった。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23K25844
• Mechanism elucidation of spatio-temporal structure formation of sheath fluctuation using optically trapped fine particles in plasmas
  Grants-in-Aid for Scientific Research
  01 Apr. 2020 - 31 Mar. 2024
  白谷 正治; 小林 達哉; 布村 正太; 石川 健治; 鎌滝 晋礼; 富田 健太郎
  シース電場の時空間構造揺らぎ形成機構の解明とこの電場揺らぎとエッチング形状揺らぎの関係解明を目的とする本研究では、4年間の研究期間において次の2項目について明らかにする。1)光捕捉微粒子を用いた低侵襲・超高感度電場計測法によるシース電場の時空間揺らぎ計測・解析(1-3年目)。2)高アスペクト比構造を用いた入射イオンの振る舞い解析(3-4年目)。2年目（2021年度）は、3次元計測用プラズマ装置の製作を行うとともに、電場計測の定量評価に最も重要である、電場較正を行い、光線光学モデルによる力の計算のとのずれは約3%であり高い精度でレーザー光による力が計算できることが確認できた。次にレーザーパワーをパラメータとして光捕捉微粒子を電極に対して水平方向に100μmごとに移動したところ、微粒子の電極に対して垂直方向（z方向）の位置は、バルクプラズマ方向へ移動した。またレーザーパワーを増加させるとレーザーの垂直方向の力の増加により微粒子のz方向の位置がバルクプラズマ側へシフトし光捕捉力の増加により微粒子が光捕捉から離脱するまでに水平移動させることができる距離が増加した。
  また、力のつり合いから、各微粒子位置における垂直方向と水平方向の電場強度EzとErを評価し、zr平面における電場ベクトルの空間分布を評価することに成功した。
  次に、プラズマ中光捕捉微粒子の位置揺動からプラズマ電場揺動を求めた。電場強度、電場揺動はプラズマ中の位置に強く依存し、水平方向の電場強度が強くなる位置では,水平方向の電場揺動が大きくなる傾向にあることを明らかにした。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Kyushu University, 20H00142
• 協同的トムソン散乱法を用いた多価電離プラズマ生成条件と放射スペクトルの関係解明
  科学研究費助成事業 基盤研究(B)
  01 Apr. 2020 - 31 Mar. 2023
  富田 健太郎
  本申請に至るまでの事前の研究活動により、光源用多価電離プラズマ、特に波長13.5nmを利用する極端紫外光源用プラズマについては、プラズマ状態と光出力が定量的に関連付けられる可能性が見いだされた。ただし計測結果はわずか数例の実験条件しかない（液滴スズドロップレット装置を用いたプラズマ生成に、共同研究先企業の装置が必要だったため、限られたマシンタイムでの計測であった）。
  このような背景のもと、本研究の目的は、様々なプラズマ生成条件にて、微小（1mm以下）・短命（30ns以下）な光源プラズマの物理パラメータ（電子密度や電子温度）の時間及び空間分解計測を行い、プラズマ生成条件と光出力の定量的な関連付けを可能とすること、と位置付けた。計測手法として協同的トムソン散乱法（主としてイオン項スペクトルの計測）を用いる。本研究の学術的独自性・創造性は、計算・シミュレーションを用いず、実験のみで光源プラズマの物理解明に必要な物理量（ne, Te, Ti, Z）の詳細な空間分布・時間変化を明らかにする点である。
  本申請の2年目（2021年度）は、プラズマを生成するための固体ターゲット種を様々に変更し（C, Al）、レーザーパワー密度依存性（10^9-10^11W/cm^2）など、種々の実験条件でトムソン散乱計測を行うことを計画した。トムソン散乱計測では、予定していた炭素、アルミに加え、銅及びスズターゲットでプラズマを生成した。炭素ターゲットについては、電子密度・電子温度に加え、プラズマの流れ（ドリフト速度）の時間・空間変化を、計測した。これらの結果を、1次元アブレーションモデルと比較した。対象とするレーザーパワー密度において、レーザー照射中のプラズマ挙動が得られたのは本研究が初めてであり、モデルと実験の比較が初めて可能となった。現在、結果を論文として投稿する準備を行っている。
  日本学術振興会, 基盤研究(B), 九州大学, 20H01880
• Proposal of Laser-Detonated Shock Tube and Improvement of Heating Prediction Accuracy of Atmospheric Entry Capsule with Precursor Radiation
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  01 Apr. 2019 - 31 Mar. 2022
  葛山 浩; 富田 健太郎
  本研究では、「①超高速突入環境を模擬できるレーザー爆轟式の革新的衝撃波管、②レーザートムソン散乱（LTS）法による先行電子の高精度計測」を提案し、その実用性・性能を評価することを目的としている。本年度（R2年度）は、昨年度（R1年度）末に納入されたTEA-CO2パルスレーザーを用いて、レーザー爆轟波の駆動およびLTS計測を実施する予定であったが、納品直後にパルスレーザーに不具合が発生したため、本年度（R2年度）6月からレーザーはメーカー（海外）に引き取られ、修理及び調整を行っている。コロナ禍の影響もあり、メーカーとのやり取りに非常に時間を要しているが、ようやく返却の目途が見え、現在、次年度（R3年度）7月の再納入を目指してメーカーと調整中である。一方で、爆轟波駆動系、LTS計測系、および同時に実施する自発光・分光計測系の構築はほぼ完了しており、レーザー返却後にすぐに実験ができる状態にある。このように、本年度もレーザー爆轟波の駆動試験は実施できなかったが、爆轟波のLTS計測では非定常計測（一発撮り）が必要となるため、アーク風洞において、LTS計測の一発撮りの試験を行い、計測ノウハウの蓄積を行った。結果は良好であり、密度10^19 m^-3および温度5,000 K程度のアークプラズマ電子を一発撮りすることに成功しており、同様の物理量を持つレーザー爆轟波の先行電子を確実に捕捉できることが示唆された。また、レーザー爆轟波の数値解析において、レーザーカットオフ現象と計算格子依存性を調べ、本実験をシミュレートする際に必要となる格子解像度を明らかにし、次年度の実験を検証するうえで、重要な知見を得た。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Yamaguchi University, 19H02348
• Understanding of anomalous transport in Hall thrusters
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  01 Apr. 2018 - 31 Mar. 2022
  Yamamoto Naoji
  To understand anomalous electron transport in a Hall thruster, plasma turbulence inside the acceleration channel was observed using a E-band microwave interferometer. The dependence of the amplitude of the turbulence on magnetic flux density, and the relations between the turbulence and other plasma perturbations and between the turbulence and the discharge current, were investigated through power spectral density and bi-coherence analysis. The turbulence has a positive relation to the discharge current, leads to anomalous electron transport inside the acceleration channel, and is coupled with ionization instability. Low frequency perturbations (several hundred Hertz) were observed; this low frequency perturbation could be a key to suppressing plasma turbulence. In addition, we showed usefulness of the short pulse width laser (picosecond laser) diagnostics for the measurement inside the Hall thrusters.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Kyushu University, 18H03815
• High-power laser experiment of magnetized collisionless shocks
  Grants-in-Aid for Scientific Research
  01 Apr. 2018 - 31 Mar. 2021
  Yamazaki Ryo
  Using GXII high-power lasers in Osaka university, we generated shock waves in laboratory that are physically identical to supernova blast waves propagating into interstellar medium. In our experiment, we imposed external magnetic field with strength of about 5T, and at the same time we directly derived local plasma density and temperatures via collective Thomson scattering measurement. We firstly obtained upstream plasma at rest that is uniform and completely magnetized. Our experimental platform will help us to simply compare the experimental data with theoretical arguments of shock physics and cosmic-ray acceleration.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Aoyama Gakuin University, 18H01232
• Laboratory astrophysics experiments using large-scale high-intensity laser systems
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  01 Apr. 2015 - 31 Mar. 2019
  Sakawa Youichi
  As generation mechanisms of high-energy charged particles or cosmic rays coming from space, acceleration by collisionless shocks, magnetic reconnection, and wakefield acceleration are strong candidates. We studied collisionless shock generation in external magnetic fields and self-generated magnetic fields by lasers, plasma-driven magnetic reconnection, and incoherent wakefield acceleration using high-power and high-intensity lasers. In the experiments, the element physics of time-evolution of collisionless shock generation and dynamics of plasmas in magnetic reconnection, etc., were clarified. In the future, it is expected that the physics of particle acceleration and the origin of cosmic rays will be approached in laser experiments.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Osaka University, 15H02154
• Development of a New Technology for Controlling the Deceleration Starting Altitude of Magnetohydrodynamic Aerobraking
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  01 Apr. 2015 - 31 Mar. 2018
  Katsurayama Hiroshi; Yamamoto Naoji; Tomita Kentaro
  To clarify the mechanism of the electromagnetic force generation on the magnetohydrodynamic braking in rarefied atmospheres, we conducted an arc wind tunnel experiment and its numerical simulation. Our previous analytical study has predicted that an insulating boundary in a flow is necessary to activate magnetohydrodynamic braking in a rarefied flow. To validate this analytical prediction, we investigated the dependency of the total drag on the insulating boundary location by varying the arc plume boundary location. As a result, the measured and computed total drags increase by applying the magnetic field. The computation is consistent with the analytical prediction because the total drag increases by moving the insulating boundary to the test model. However, the measured electromagnetic drag increase is insensitive to the insulating boundary location because the flow is denser than expected.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Yamaguchi University, 15H04200
• development of ionic charge, electron density, and electron temperature measurement system for soft-X ray light sources
  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)
  01 Apr. 2015 - 31 Mar. 2018
  Tomita Kentaro
  Soft X-ray light source have been used for various applications, such as extreme-ultraviolet(EUV) light sources (wavelength 13.5 nm) for next-generation semiconductor lithography system and water-window light sources (wavelength 2.3-4.4 nm), Laser-produced plasma is an attractive candidate for the Sof X-ray light source, because the plasma can be easily produced by table-top laser system. In order to optimize the plasma as the soft-X-ray light sources, to measure and control fundamental plasma parameters, such as averaged ionic charge state (Z), electron density (ne), and electron temperature (Te) are prerequisite. We have developed a new measurement system to obtain these plasma parameters. In our system, both ion and electron feature spectra of collective Thomson scattering have been observed simultaneously. From these spectra, it is possible to determine Z, ne, and Te.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (A), Kyushu University, 15H05472
• Collisionless shock generation using large-scale laser systems
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  01 Apr. 2012 - 31 Mar. 2015
  SAKAWA Youichi; YONEDA Hitoki; TAKABE Hideaki; MORITAKA Toseo; TOMITA Kentaro; MORITA Taichi
  Collisionless shock experiments were conducted using supersonic counter-stream plasmas with parallel double-plane (DP) target. On Gekko XII HIPER laser experiment, collective Thomson scattering ion-term measurement was conducted. Electron and ion temperatures, flow velocity, electron density were measured for counter-streaming plasmas and shock, and their temporal-evolution was investigated.
  On OMEGA laser (USA) experiment, Weibel filaments were observed by D-3He fusion produced proton radiography.
  On the NIF laser (USA) experiment, DD neutrons/proton and strong x-ray emission from the hot plasmas in the middle of the two planes are observed with CD DP target. These results indicate that neutrons are produced in a shock-heated hot plasma.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Osaka University, 24340141
• 協同的トムソン散乱法による無衝突衝撃波の研究
  大阪大学レーザーエネルギー学研究センター共同利用・共同研究
  Apr. 2012 - Mar. 2015
  富田健太郎
  大阪大学レーザーエネルギー学研究センター, Principal investigator, Competitive research funding
• 次世代直流・交流電力システムを視野に入れたSF6・代替ガスアーク遮断現象の高精度実験および高精度数値解析 －未知なるアークプラズマ現象解明への挑戦－
  パワーアカデミー研究助成，特別推進研究
  Dec. 2013 - Nov. 2014
  田中康規
  パワーアカデミー, Competitive research funding
• ナノ界面近傍における電子状態の診断
  科学研究費助成事業 新学術領域研究(研究領域提案型)
  01 Apr. 2012 - 31 Mar. 2014
  富田 健太郎
  気相であるプラズマと電極等の固相間の界面は、プラズマプロセスに直接的に関わると考えられるため、これまで様々な研究が行われてきた。本研究では、低圧プロセスプラズマと、液面と接する大気圧プラズマを対象に、プラズマの電子状態診断を行った。
  大気圧プラズマは、近年では固体ではなく、液体と接した状態に注目が集まっている。これは、大気圧プラズマの医療やバイオ応用を考えた時、液体とプラズマの接触が避けられないからである。しかし、液体とプラズマが接することで、プラズマの基礎物理量（電子密度や電子温度）がどのように影響を受けるかは、まだ明らかになっていない。
  このような背景のもと、液体と接する大気圧プラズマ中の電子密度・電子温度を、レーザートムソン散乱法を用いて測定した。トムソン散乱法を用いたのは、液体を含まない大気圧プラズマの診断手法として、高い信頼性を有しているからである。一方、大気圧程度に密度の高いガス中に計測用レーザーを入射すると、母ガスを多光子電離してしまい、計測が不正確になる恐れがある。本研究ではそのような擾乱に配慮し、十分にレーザーパワー密度が低い領域で、計測を行った。十分に低いパワー密度では、その反面、得られるトムソン散乱光強度が微弱となり、レーザー1000ショット程度の積算計測が必須となる。そのような計測が実現できるナノ秒パルス放電と、蒸気圧が極めて低い液体材料（イオン液体）を併用することで、安定した放電生成環境の元、液体電極使用による放電状況の変化を定量的に把握した。
  低圧プロセスプラズマについては、数Torrオーダーのプローブ計測が困難となる圧力のプラズマについて、トムソン散乱法が適用可能な領域を明らかにした。
  日本学術振興会, 新学術領域研究(研究領域提案型), 九州大学, 24110715
• 高効率かつ低コストな次世代リソグラフィー光源開発のための評価技術の確立
  JST研究成果最適展開支援プログラムA-STEP・FSステージ探索タイプ
  Dec. 2012 - Nov. 2013
  富田健太郎
  JST, Principal investigator, Competitive research funding
• SF6ガスに代わる遮断ガス模索のためのアーク放電特性の研究
  パワーアカデミー研究助成・萌芽研究
  Dec. 2012 - Nov. 2013
  富田健太郎
  パワーアカデミー, Principal investigator, Competitive research funding
• Studies of arc discharges for gas circuit breakers
  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
  2011 - 2013
  TOMITA KENTARO
  Gas circuit breakers (GCBs) are one of the most important components for high voltage power system. For high voltage circuit breaker rated at more than 72 kV, high-pressure SF6 gas is commonly used as arc quenching medium. However, SF6 has very high global warming potential. It has thus been desired to search for alternative gases for SF6. For effective searching and/or development of such alternative gases, diagnostics of arc discharges generated inside GCBs are essentially crucial. Especially, precise measurements of electron density in a decaying arc discharge in transient state are indispensable.
  In order to measure electron density in arcs, in this study, laser Thomson scattering has been applied to arcs generated with several types of gases and polymer materials, which are used around electrodes. As a result of the measurement, clear differences of spatiotemporal evolutions were found for arcs generated with different conditions.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Kyushu University, 23760262
• Studies on the efficient emission mechanism of plasma display panels
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2009 - 2011
  UCHINO Kiichiro; TOMITA Kentaro
  Recently, there are some reports that show the high efficacy in the ultraviolet generation form the plasma display panels(PDP). One of the factors allowing such high efficacy is the pulse width to be very short. However, the mechanism how the short pulsed discharges are related with the high efficacy is not clear. This study aims to clarify the mechanism based on the measurements of basic parameters such as electron density and electron temperature of short pulsed discharges. Measurements were performed for the dielectric discharge simulating the PDP discharge and a capacity coupled discharge(CCD). It was confirmed that the short pulsed discharges for both realized improvements in the ultraviolet generation, ant possible causes for that are discussed.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyushu University, 21360042
• 高効率かつ長寿命LED照明開発のための高精度リアルタイム温度計測システムの開発
  JST研究成果最適展開支援プログラムA-STEP，FSステージ探索タイプ
  Aug. 2009 - Mar. 2010
  富田健太郎
  JST, Principal investigator, Competitive research funding