Research activity information

• Influence of cusp-shaped magnetic fields on plasma density and thrust in an RF plasma thruster with a magnetic nozzle

  Takeru Furukawa, Kento Shimasaki, Satoshi Nakamoto, Hiromasa Takeno

  In a radiofrequency (RF) plasma thruster device utilizing a cusp-shaped magnetic field, we investigate the dependence of plasma parameters on operational conditions. Among the conditions, this study focused on the cusp-field condition and found that the axial profiles of the plasma parameters vary depending on the field conditions. The plasma density profile is affected by the distance between the cusp point and the position of the RF antenna. When the cusp strength increases, the cusp condition enhances plasma density and the total thrust, which is the sum of the thrust components of the electron static pressure and diamagnetic current. We propose an ideal cusp point concerning the antenna position for optimal performance in the thruster device. This paper highlights how cusp-shaped magnetic fields influence electron dynamics as an operational index of the RF plasma thruster with a magnetic nozzle.

  AIP Publishing, Nov. 2024, Physics of Plasmas, 31(11) (11)

  Link to Kobe Univ. Repository (Kernel)


• Examination of Efficiency Dependence on Deceleration Voltage in a Traveling Wave Direct Energy Converter Simulator

  Hiromasa TAKENO, Kazuhiro SHIBATA, Satoshi NAKAMOTO, Takeru FURUKAWA, Yousuke NAKASHIMA

  Japan Society of Plasma Science and Nuclear Fusion Research, Jun. 2023, Plasma and Fusion Research, 18, 2405053 - 2405053


• Improvement of Electron Recovery Using a Magnetic Field with a Low Mirror Ratio in a Secondary Electron Direct Energy Converter Simulator

  Atsuya KURISUNO, Satoshi NAKAMOTO, Kazuya ICHIMURA, Hiromasa TAKENO, Yuichi FURUYAMA, Akira TANIIKE

  Japan Society of Plasma Science and Nuclear Fusion Research, Jul. 2020, Plasma and Fusion Research, 15, 2405046 - 2405046


• Analytical Experiment of Time Evolution of Deceleration Effect in Traveling Wave Direct Energy Converter Using Dual-Frequency Modulation

  SHIBATA Kazuhiro, SATO Hiroki, TAKENO Hiromasa, ICHIMURA Kazuya, NAKAMOTO Satoshi, NAKASHIMA Yousuke

  Feb. 2019, Plasma and Fusion Research, 14, 2405027


• Experimental analysis on variation of the amount of particles passing through traveling wave direct energy converter

  Kazuhiro Shibata, Hiromasa Takeno, Kazuya Ichimura, Satoshi Nakamoto, Yousuke Nakashima

  Japan Society of Plasma Science and Nuclear Fusion Research, 2019, Plasma and Fusion Research, 14


• Recent Advancement of Research on Plasma Direct Energy Conversion

  TAKENO Hiromasa, ICHIMURA Kazuya, NAKAMOTO Satoshi, NAKASHIMA Yousuke, MATSUURA Hiroto, MIYAZAWA Junichi, GOTO Takuya, FURUYAMA Yuichi, TANIIKE Akira

  Jan. 2019, Plasma and Fusion Research, 14, 2405013


• Performance improvement due to additional collectors in a secondary electron direct energy converter simulator

  NAKAMOTO Satoshi, KONNO Shota, ICHIMURA Kazuya, TAKENO Hiromasa, FURUYAMA Yuichi, TANIIKE Akira

  Nov. 2018, Fusion Engineering and Design, 136, 157 - 161


• Development of calorimeter system for conceptual study of CuspDEC divertor

  ICHIMURA Kazuya, KITAHARA Yuki, NONDA Yuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  Nov. 2018, Fusion Engineering and Design, 136, 381 - 385


• Measurement of Heat Quantity in a Small Cusp-Type Direct Energy Converter for Divertor Thermal Load Reduction

  NONDA Yuya, YAMADA Hirotaka, KITAHARA Yuki, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  May 2018, Plasma and Fusion Research, 13, 3405050

  Link to Kobe Univ. Repository (Kernel)


• Charge Separation Characteristics of a Newly Constructed CUSPDEC Device Using Permanent Magnets

  TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya, MIYAZAWA Junichi, GOTO Takuya, NAKASHIMA Yousuke, KATANUMA Isao

  Oct. 2016, Annual Report of National Institute for Fusion Science April2015-March2016, 454


• Studies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversion

  Masaki Hamabe, Hiroaki Izawa, Hiromasa Takeno, Satoshi Nakamoto, Kazuya Ichimura, Yousuke Nakashima

  Japan Society of Plasma Science and Nuclear Fusion Research, 2016, Plasma and Fusion Research, 11(1) (1), 2405028 - 2405028


• Variation in emission and energy recovery concerning incident angle in a scheme recovering high energy ions by secondary electrons

  Takayuki Wada, Shota Konno, Satoshi Nakamoto, Hiromasa Takeno, Yuichi Furuyama, Akira Taniike

  Japan Society of Plasma Science and Nuclear Fusion Research, 2016, Plasma and Fusion Research, 11(1) (1), 2405029


• Studies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversion

  Masaki Hamabe, Hiroaki Izawa, Hiromasa Takeno, Satoshi Nakamoto, Kazuya Ichimura, Yousuke Nakashima

  Japan Society of Plasma Science and Nuclear Fusion Research, 2016, Plasma and Fusion Research, 11(1) (1), 2405028


• Experimental Verification of Constant Deceleration of TWDEC for its Miniaturization

  TAKENO Hiromasa, NAKAMOTO Satoshi, MIYAZAWA Junichi, GOTO Takuya, NAKASHIMA Yousuke, KATANUMA Isao

  Nov. 2015, Annual Report of National Institute for Fusion Science April2014-March2015, 469


• ENHANCED ENERGY RECOVERY IN A SECONDARY ELECTRON DIRECT ENERGY CONVERTER THROUGH REDUCTION OF THE MAGNETIC MIRROR EFFECT

  Satoshi Nakamoto, Yousuke Takeshita, Shota Hagihara, Takayuki Wada, Hiromasa Takeno, Yasuyoshi Yasaka, Yuichi Furuyama, Akira Taniike

  Jul. 2015, FUSION SCIENCE AND TECHNOLOGY, 68(1) (1), 166 - 170


• Studies on Plasma Production and Ion Heating by Using Only a Single Helical Antenna for a Simple Thruster

  HAMANO Tsuyoshi, KINOSHITA Ryosuke, NAKATSUKA Yuki, YASAKA Yasuyoshi, NAKAMOTO Satoshi, TAKENO Hiromasa

  Apr. 2015, Plasma and Fusion Research, 10, 3406032


• Characterization of Secondary Electron Collection for Energy Recovery from High Energy Ions with a Magnetic Field

  HAGIHARA Shota, WADA Takayuki, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  A traveling wave direct energy converter (TWDEC) is expected to be used as an energy recovery device for fast protons produced during the D-³He nuclear fusion reaction. Some protons, however, are not fully decelerated and pass through the device. A secondary electron direct energy converter (SEDEC) was proposed as an additional device to recover the protons passing through a TWDEC. In our previous study, magnetic field was applied for efficient secondary electron (SE) collection, but the SEs were reflected close to the collector due to the magnetic mirror effect and the collection was degraded. Herein, a new arrangement of magnets is proposed to be set away from the collector, and experiments in various conditions are performed. An appropriate arrangement away from the collector resulted in the improvement of SE collection.

  The Japan Society of Plasma Science and Nuclear Fusion Research, Mar. 2015, Plasma and Fusion Research, 10, 3405025 - 3405025


• Fundamental Studies on Secondary Electron Direct Energy Converter with Magnetic Field

  NAKAMOTO Satoshi, TAKESHITA Yousuke, HAGIHARA Shota, WADA Takayuki, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  Dec. 2014, Collection of Papers for The 10th Internatinal Conference on Open Magnetic System for Plasma Confinement, 90 - 93


• Bi-Directional Excitation of Radio Frequency Waves Using a Helical Antenna in Non-Uniform Plasmas towards a Compact Magnetoplasma Thruster

  YASAKA Yasuyoshi, HAYASHI Yoshifumi, TAKENO Hiromasa, NAKAMOTO Satoshi

  Dec. 2014, Open Journal of Applied Sciences, 4(13) (13), 523 - 532


• Analysis of Particle Distribution due to Modulation in Traveling Wave Direct Energy Converter

  FUJITA Kouhei, TOGO Yusuke, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  Dec. 2014, Collection of Papers for The 10th Internatinal Conference on Open Magnetic System for Plasma Confinement, 94 - 97


• Variation of Charge Separation due to Radio Frequency Application in a Cusp-type Direct Energy Converter

  TAKENO Hiromasa, HAMABE Masaki, NAKAMOTO Satoshi, YASAKA Yasuyoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  Nov. 2014, Proceedings of PLASMA2014, 18PB - 031


• Bi-directional excitation of ICRF waves in non-uniform plasmas towards a compact RF-driven magnetoplasma thruster

  YASAKA Yasuyoshi, HAYASHI Yoshifumi, TAKENO Hiromasa, NAKAMOTO Satoshi, KINOSHITA Ryosuke

  Jul. 2013, Proceedings of 31st International Conference on Phenomena in Ionized Gases, PS2 - 058


• EXAMINATION ON PLASMA PRODUCTION AND ION HEATING FOR ELECTRIC PROPULSION USING A SINGLE HELICAL ANTENNA

  Y. Hayashi, R. Kinoshita, H. Wakabayashi, S. Nakamoto, H. Takeno, Y. Yasaka

  May 2013, FUSION SCIENCE AND TECHNOLOGY, 63(1T) (1T), 389 - 391


• BASIC CHARACTERISTICS OF SECONDARY ELECTRON EMISSION FROM FOIL ELECTRODES FOR NEW ENERGY RECOVERY SCHEME OF HIGH ENERGY IONS IN AN ADVANCED FUSION

  D. Akashi, Y. Takeshita, S. Nakamoto, H. Takeno, Y. Yasaka, Y. Furuyama, A. Taniike

  May 2013, FUSION SCIENCE AND TECHNOLOGY, 63(1T) (1T), 301 - 303


• Novel Control of Magnetoplasma Thruster by Using a Rotating Radio Frequency System

  Y. Yasaka, S. Nishino, M. Yamamoto, S. Nakamoto, H. Takeno, H. Yonemori

  Mar. 2012, JOURNAL OF PROPULSION AND POWER, 28(2) (2), 364 - 370


• Basic Experiment on a Magnetoplasma Thruster Driven by Phase-Controlled RF

  YASAKA Yasuyoshi, YAMAMOTO Masanori, HAYASHI Yoshifumi, NAKAMOTO Satoshi, TAKENO Hiromasa

  Sep. 2011, Proc. 32nd Int'l. ElectricPropulsion Conf., IEPC-2011-057


• Novel Control of Magnetoplasma Thruster by Using a Rotating RF System

  YASAKA Yasuyoshi, Nishino Satoshi, YAMAMOTO Masanori, NAKAMOTO Satoshi, TAKENO Hiromasa, YONEMORI Hideto

  Jan. 2011, Proceedings of 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, AIAA 2011-1072 (7pp)


• Improvement of Cusp Type and Traveling Wave Type Plasma Direct Energy Converters Applicable to Advanced Fusion Reactor

  TAKENO Hiromasa, YASAKA Yasuyoshi, NAKAMOTO Satoshi

  Oct. 2010, Abstract Book of 23rd IAEA Fusion Energy Conference, p. 476


• Improvement of an applicator for hyperthermia in long wavelength microwave using small loop antennas

  MATSUMOTO Hiroshi, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, KAWAI Shigeaki, MITANI Tomohiko, SHINOHARA Naoki, NAMIKI Hironori

  Nov. 2007, Proceedings of 2007 Japan-Korea Joint Symposium on Electrical Discharge and High Voltage Engineering, pp. 43-46


• Fundamental study on localized heating in hyperthermia using phase control of long-wavelength microwaves

  Hiroshi Matsumoto, Hiroki Ishida, Satoshi Nakamoto, Hiromasa Takeno, Yasuyoshi Yasaka, Shigeaki Kawai, Mitani Tomohiko, Shinohara Naoki, Namiki Hironori

  Institute of Electrical Engineers of Japan, 2007, IEEJ Transactions on Electronics, Information and Systems, 127(11) (11), 3 - 1838


• Effective Destruction of Easy-break Concrete by Microwave Irradiation Using Heat at the Contact Point of Conducting Materials

  TABAYASHI Junji, NISHIKAWA Norimitsu, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, TSUJI Masanori, OHNO Kazuki, NAMIKI Hironori, URABE Kei

  2004, Proceeding of The 2nd International Symposium on Sustainable Energy System, 147


• Studies on Easy-break Concrete Heating due to Microwave Strong Field Created by Conducting Marerial

  NISHIO hidetaka, TABAYASHI Junji, NAKAMOTO Satoshi, TAKENO Hiromasa, OHSAWA Yasuharu, NAMIKI Hironori

  Nov. 2003, Proceedings of 2003 Japan-Korea Joint Symposium on Electrical Discharge and High Voltage Engineering., 205-208


• Improvement of spatial resolution on surface charge measurement by applying an artificial neural network to obtain instrument function.

  TAKENO Hiromasa, TAKASHIMA Tohru, NAKAMOTO Satoshi, OHSAWA Yasuharu, ARAI Kenji

  Aug. 2003, Proceedings of the ⅩⅢth International Symposium on High Voltage Engineering., CD-ROM,No.385

• 長波長 マイクロ波を用いた低侵襲ハイパーサーミアの基礎研究?

  竹野裕正, 田畑陽平, 中本聡, 八坂保能, 三谷友彦, 篠原真毅, 並木宏徳

  2009, 第24 回宇宙太陽発電時限研究専門委員会研究会


• 327 Analysis of Microwave Propagation for Infrared Thermography Method Using Microwave Heating

  TAKENO Hiromasa, NISHIKAWA Norimitsu, NAKAMOTO Satoshi, YASAKA Yasuyoshi, KOBAYASHI Yuuki, TSUJI Masanori, NAMIKI Hironori

  日本材料学会, 2006, 学術講演会講演論文集, 55, 287 - 288


• 603 Compaction of a Carbon-fiber Antenna for Easy-break Concrete

  TAKENO Hiromasa, ISHIDA Hiroki, NISHIKAWA Norimitsu, TABAYASHI Junji, NAKAMOTO Satoshi, YASAKA Yasuyoshi, NAMIKI Hironori

  日本材料学会, 2005, 学術講演会講演論文集, 54, 173 - 174


• 818 Easy-break Concreteにおける導電材混入効果の解析実験(コンクリート耐久性・リサイクル・変形,一般セッション,第53期学術講演会)

  竹野 裕正, 田林 準史, 中本 聡, 八坂 保能, 並木 宏徳

  日本材料学会, 2004, 学術講演会講演論文集, 53, 509 - 510


• Improvement of Heating Efficiency of Easy-break Concrete due to Microwave Strong Field Formed at Sharp Edges of Conducting Material

  TABAYASHI Junji, KIRIYAMA Yusuke, NISHIO Hidetaka, NAKAMOTO Satoshi, TAKENO Hiromasa, OHSAWA Yasuharu, NAMIKI Hironori

  12 Dec. 2003, 電気学会研究会資料. ED, 放電研究会, 2003(239) (239), 71 - 76


• Diagnosis of Insulation Degradation of DC-GIS Using Pulsating Voltage (III)

  KUROIWA Yasuo, NAKAMOTO Satoshi, TAKENO Hiromasa, OHSAWA Yasuharu, ARAI Kenji

  07 Dec. 2000, 電気学会研究会資料. ED, 放電研究会, 2000(168) (168), 7 - 12


• Diagnosis of Insulation Degradation of DC-GIS Using Pulsating Voltage (II)

  SUGIYAMA Yasuyuki, KUROIWA Yasuo, NAKAMOTO Satoshi, TAKENO Hiromasa, OHSAWA Yasuharu, ARAI Kenji

  03 Dec. 1999, 電気学会研究会資料. ED, 放電研究会, 1999(189) (189), 73 - 78


• Analysis on Mechanism of Discharge Induction by Laser Produced Plasma in a Short Air Gap

  NANAHARA Atsuo, TAKENO Hiromasa, WANG Xiaoli, NAKAMOTO Satoshi, OHSAWA Yasuharu, CHO Mengu, ARAI Kenji

  05 Dec. 1997, 電気学会研究会資料. ED, 放電研究会, 1997(226) (226), 71 - 76


• Analytical Experiments on Effect of Shock Wave to Laser Induced Discharge

  TAKENO Hiromasa, NANAHARA Atsuo, WANG Xiaoli, NAKAMOTO Satoshi, OHSAWA Yasuharu, CHO Mengu, ARAI Kenji

  17 Jun. 1997, 電気学会研究会資料. ED, 放電研究会, 1997(39) (39), 19 - 23


• Research on the Degradation of Insulating Material by Feeble Discharge in SF_6 Gas due to the Quantitative Measurement of Discharge Light

  TAKENO Hiromasa, ZHOU Shijie, NAKAMOTO Satoshi, MORI Masafumi, ARAI Kenji

  電気学会, Nov. 1996, The Transactions of the Institute of Electrical Engineers of Japan. A, 116(11) (11), 959 - 963

• Effect of low mirror ratio magnetic field in fast ion energy recovery method using secondary electron emission

  KURISUNO Atsuya, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa, FURUYAMA Yuichi, TANIIKE Akira

  The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, 吹田


• 二次電子放出を利用した高速イオンのエネルギー回収における低ミラー比磁場の効果

  KURISUNO Atsuya, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa, FURUYAMA Yuichi, TANIIKE Akira

  神戸大学研究基盤センター若手フロンティア研究会2018, Dec. 2018, 神戸


• Study of ion beam extraction and transport in the composite-plasma source for researches of direct energy converter

  ICHIMURA Kazuya, OKAMOTO Yuuki, NAKAMOTO Satoshi, TAKENO Hiromasa

  The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, 吹田


• Dependence of Antenna Position in a Simulation Experiment of Plasma Thruster Using a Single Helical Antenna

  YAMAZUI Hiromune, INUI Kento, TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya

  The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, 吹田


• Studies on transport of ion beam in simulator of traveling wave direct energy converter

  HASHIGUCHI Kazuya, SHIBATA Kazuhiro, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, NAKASHIMA Yousuke

  The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, 吹田


• Studies on Plasma Generation and RF Field Distribution Measurement on Variable Length Single Helical Antenna Type Plasma Thruster

  MARUKI Yoshiki, TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya

  The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, 吹田


• Improvement of ion-ion separation and collection by modification of electrode structure in a cusp type direct energy converter

  OKAMOTO Yuuki, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MIYAZAWA Junichi, GOTO Takuya

  The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, Toki


• Improvement of evaluation of heat quantity in a simulation experiment of divertor thermal load reduction by using a charge separation device

  YAMADA Hirotaka, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, Toki


• Experimental analysis on variation of the amount of particles passing through traveling wave direct energy converter

  SHIBATA Kazuhiro, HASHIGUCHI Kazuya, TAKENO Hiromasa, ICHIMURA Kazuya, NAKAMOTO Satoshi, NAKASHIMA Yousuke

  The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, Toki


• Effect of axial gradient of magnetic field in a plasma source of a thruster simulator using a single helical antenna

  INUI Kento, YAMAZUI Hiromune, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa

  The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, Toki


• Working characteristics of a combined plasma source for ion-ion separation experiments in direct energy conversion

  OKAMOTO Yuuki, HARADA Kouhei, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MIYAZAWA Junichi, GOTO Takuya

  12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, Tsukuba


• Recent advancement of research on plasma direct energy conversion

  TAKENO Hiromasa, ICHIMURA Kazuya, NAKAMOTO Satoshi, NAKASHIMA Yousuke, MATSUURA Hiroto, MIYAZAWA Junichi, GOTO Takuya, FURUYAMA Yuichi, TANIIKE Akira

  12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, Tsukuba


• Improvement of electron collection using a magnetic field suppressing mirror effect in a secondary electron direct energy converter simulator

  KURISUNO Atsuya, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa, FURUYAMA Yuichi, TANIIKE Akira

  12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, Tsukuba


• Analytical experiment of time evolution of deceleration effect in traveling wave direct energy converter using dual-frequency modulation

  SHIBATA Kazuhiro, SATO Hiroki, TAKENO Hiromasa, ICHIMURA Kazuya, NAKAMOTO Satoshi, NAKASHIMA Yousuke

  12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, Tsukuba


• Measurement of Heat Quantity in a Small Cusp-type Direct Energy Converter for Divertor Thermal Load Reduction

  NONDA Yuya, YAMADA Hirotaka, KITAHARA Yuki, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  The joint meeting of the 26th International Toki Conference and The 11th Asia Plasma and Fusion Association Conference, Dec. 2017, 土岐市


• A Preliminary Study of Ion-Ion Separation in Cusp-type Direct Energy Converter

  HARADA Kouhei, OKAMOTO Yuki, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MIYAZAWA Junichi, GOTO Takuya

  The joint meeting of the 26th International Toki Conference and The 11th Asia Plasma and Fusion Association Conference, Dec. 2017, 土岐市


• Radial Dependence of Ion Energy Distribution in a Simulation Experiment of Plasma Thruster Using a Single Helical Antenna

  KITA Masayuki, INUI Kento, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa

  Plasma Conference 2017, Nov. 2017, 姫路市


• Studies on Plasma Production Control by the Length of a Single Helical Antenna for a Simple Electric Thruster

  SHIMIZU Yuuki, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa

  Plasma Conference 2017, Nov. 2017, 姫路市


• 単一ヘリカルアンテナ型電気推進エンジンにおける生成プラズマの径方向分布に関する研究

  INUI Kento, KITA Masayuki, SHIMIZU Yuuki, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa

  平成29年電気関係学会関西連合大会, Nov. 2017, 東大阪市


• Studies on Scattering due to Field of Bunched Ions in a Traveling Wave Direct Energy Converter Simulator

  TAKENO Hiromasa, KONDO Futoshi, WAKAIZUMI Takahiro, ICHIMURA Kazuya, NAKAMOTO Satoshi, NAKASHIMA Yousuke

  Plasma Conference 2017, Nov. 2017, 姫路市


• カスプ型直接エネルギー変換器でのイオン-イオン分離の模擬実験研究

  OKAMOTO Yuki, HARADA Kouhei, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MIYAZAWA Junichi, GOTO Takuya

  平成29年電気関係学会関西連合大会, Nov. 2017, 東大阪市


• Development of Calorimeter System for a Conceptual Study of CuspDEC Divertor

  ICHIMURA Kazuya, KITAHARA Yuuki, NONDA Yuuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  the 13th International Symposium on Fusion Nuclear Technology, Sep. 2017, 京都市


• Analytical Experiments on Scattering of High Energy Ions in a Secondary Electron Direct Energy Converter Simulator

  NAKAMOTO Satoshi, KONNO Shota, ICHIMURA Kazuya, TAKENO Hiromasa, FURUYAMA Yuuichi, TANIIKE Akira

  the 13th International Symposium on Fusion Nuclear Technology, Sep. 2017, 京都市


• 二次電子放出を利用した高速イオンからのエネルギー回収法における電極間滞留電子の測定

  SHIMIZU Yuuki, KONNO Shota, NAKAMOTO Satoshi, TAKENO Hiromasa, FURUYAMA Yuuichi, TANIIKE Akira

  平成28年電気関係学会関西連合大会, Nov. 2016, 堺市


• 二次電子放出を利用した高速イオンからのエネルギー回収装置における捕集電極構造の改良

  KONNO Shota, SHIMIZU Yuuki, IHARA Kousuke, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa, FURUYAMA Yuuichi, TANIIKE Akira

  平成28年電気関係学会関西連合大会, Nov. 2016, 堺市


• Development of a Combined Plasma Source Simulating Helium 3 Fusion Reactor for Direct Energy Conversion

  TAKENO Hiromasa, HARADA Kouhei, ICHIMURA Kazuya, NAKAMOTO Satoshi, MIYAZAWA Junichi, GOTO Takuya

  プラズマ・核融合学会第33回年会, Nov. 2016, 仙台市


• Refinement of a Small Cusp-type Device to Reduce the Divertor Thermal Loads by Direct Energy Conversion

  NONDA Yuya, KITAHARA Yuki, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  プラズマ・核融合学会第33回年会, Nov. 2016, 仙台市


• 単一ヘリカルアンテナ型電気推進エンジンのガス圧力制御によるプラズマ生成量の変化に関する研究

  KITA Masayuki, KURASHITA Noriya, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa

  平成28年電気関係学会関西連合大会, Nov. 2016, 堺市


• Study on the measurement of ion heating effect by a single helical antenna for a simple thruster

  KURASHITA Fumiya, KITA Masayuki, SHIMIZU Yuki, NAKAMOTO Satoshi, ICHIMURA Kazuya, TAKENO Hiromasa

  プラズマ・核融合学会第33回年会, Nov. 2016, 仙台市


• 静電減速によるダイバータ熱負荷低減のための熱量測定に関する研究

  KITAHARA Yuuki, NONDA Yuuya, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MATSUURA Hiroto, NAKASHIMA Yousuke

  平成28年電気関係学会関西連合大会, Nov. 2016, 堺市


• カスプ型直接エネルギー変換器におけるイオン－イオン電界分離のための電極構造に関する研究

  HARADA Kouhei, ICHIMURA Kazuya, NAKAMOTO Satoshi, TAKENO Hiromasa, MIYAZAWA Junichi, GOTO Takuya

  平成28年電気関係学会関西連合大会, Nov. 2016, 堺市


• GAMMA 10におけるプラズマ直接発電器の小型化のための基礎研究

  TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya, MATSUURA Hiroto, MIYAZAWA Junichi, GOTO Takuya, NAKASHIMA Yousuke, KATANUMA Isao

  平成28年度筑波大学プラズマ研究センターシンポジウム, Jul. 2016, つくば市


• 永久磁石によるカスプ磁場型荷電粒子分離における大型ダイバータ模擬設備用実験装置の開発に関する研究

  KITAHARA Yuuki, WATANABE Takuya, TOMITA Yutaka, TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  平成27年電気関係学会関西連合大会, Nov. 2015, 寝屋川市


• カスプ型直接エネルギー変換器のラインカスプ上高周波電界の電子の運動に対する影響に関する研究

  IZAWA Hiroaki, HAMABE Masaki, TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  平成27年電気関係学会関西連合大会, Nov. 2015, 寝屋川市


• Variation of Particle Orbit due to Radio Frequency Field in a Cusp-type Direct Energy Converter

  TAKENO Hiromasa, HAMABE Masaki, IZAWA Hiroaki, NAKAMOTO Satoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  プラズマ・核融合学会第32回年会, Nov. 2015, 名古屋市


• Variation in secondary electron collection and energy recovery concerning electrode angle in a high energy ion penetration scheme

  WADA Takayuki, KONNO Shota, NAKAMOTO Satoshi, TAKENO Hiromasa, FURUYAMA Yuichi, TANIIKE Akira

  25th International Toki Conference, Nov. 2015, Toki, Japan


• Studies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversion

  HAMABE Masaki, IZAWA Hiroaki, TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  25th International Toki Conference, Nov. 2015, Toki, Japan


• Studies on power dependence of plasma production and ion heating by a single helical antenna for a simple thruster

  NAKATSUKA Yuki, KURASHITA Fumiya, NAKAMOTO Satoshi, TAKENO Hiromasa

  25th International Toki Conference, Nov. 2015, Toki, Japan


• Improvement of charge separation by increase of magnets in a PM-CuspDEC simulator

  WATANABE Takuya, KITAHARA Yuuki, TAKENO Hiromasa, NAKAMOTO Satoshi, ICHIMURA Kazuya, NAKASHIMA Yousuke

  25th International Toki Conference, Nov. 2015, Toki, Japan


• 2次電子放出を利用した高速イオンからのエネルギー回収における2 次電子のエネルギー分布

  KONNO Shota, WADA Takayuki, NAKAMOTO Satoshi, TAKENO Hiromasa, FURUYAMA Yuichi, TANIIKE Akira

  平成27年電気関係学会関西連合大会, Nov. 2015, 寝屋川市


• 電気推進エンジンのためのガス圧力制御による高密度プラズマ生成と特性評価に関する研究

  NAKATSUKA Yuki, HAMANO Takeshi, YASAKA Yasuyoshi, NAKAMOTO Satoshi, TAKENO Hiromasa

  平成26年電気関係学会関西支部連合大会, Nov. 2014, Ikoma


• Studies on Plasma Production and Ion Heating by Using Only a Single Helical Antenna for a Simple Thruster

  HAMANO Takeshi, KINOSHITA Ryosuke, NAKATSUKA Yuki, YASAKA Yasuyoshi, NAKAMOTO Satoshi, TAKENO Hiromasa

  24th International Toki Conference, Nov. 2014, Toki


• Characterization of Secondary Electron Collection with Magnetic Field for Energy Recovery from High Energy Ion

  HAGIHARA Shota, WADA Takayaki, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  24th International Toki Conference, Nov. 2014, Toki


• 2次電子放出を利用した高エネルギーイオンからのエネルギー回収における磁場導入効果の数値計算

  WADA Takayuki, HAGIHARA Shota, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  平成26年電気関係学会関西支部連合大会, Nov. 2014, Ikoma


• Studies on Plasma Production and Ion Heating Using Bi-Directional Excitation of High Frequency Waves for Electric Propulsion

  NAKAMOTO Satoshi, KINOSHITA Ryosuke, HAMANO Takeshi, YASAKA Yasuyoshi, TAKENO Hiromasa

  The 10th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2014, Daejeon


• 単一アンテナによるプラズマの生成と加熱に向けたプラズマスタートアップに関する研究

  HAMANO Takeshi, KINOSHITA Ryosuke, YASAKA Yasuyoshi, NAKAMOTO Satoshi, TAKENO Hiromasa

  平成25年電気関係学会関西支部連合大会, Nov. 2013, 寝屋川


• Study of Energy Recovery from High Energy Ions Using Secondary Electron Emission with Magnetic Field

  TAKESHITA Yousuke, HAGIHARA Shota, AKASHI Daisuke, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  9th General Scientific Assembly of the Asia Plasma and Fusion Association in 2013, Nov. 2013, Gyeongju


• Studies on Plasma Production and Ion Heating Using High Frequency for Electric Propulsion

  KINOSHITA Ryosuke, HAMANO Takeshi, HAYASHI Yoshifumi, NAKAMOTO Satoshi, YASAKA Yasuyoshi, TAKENO Hiromasa

  23rd International Toki Conference, Nov. 2013, Toki


• 2次電子放出を利用した高エネルギーイオンからのエネルギー回収に向けた数値計算による評価

  HAGIHARA Shota, TAKESHITA Yousuke, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  平成25年電気関係学会関西支部連合大会, Nov. 2013, 寝屋川


• 箔電極からの2次電子放出を利用した高エネルギーイオンのエネルギー回収に関する研究(II)

  TAKESHITA Yousuke, AKASHI Daisuke, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  平成24年電気関係学会関西支部連合大会, Dec. 2012, 関西大学


• 電気推進のためのヘリカルアンテナを用いたプラズマ生成と加熱に関する研究

  KINOSHITA Ryosuke, HAYASHI Yoshifumi, NAKAMOTO Satoshi, YASAKA Yasuyoshi, TAKENO Hiromasa

  平成24年電気関係学会関西支部連合大会, Dec. 2012, 関西大学


• 傾斜配置ループアンテナアレイと空洞共振器を用いた非侵襲ハイパーサーミアのためのFDTD法による電界分布の数値解析

  OKAMOTO Kazuya, TAKENO Hiromasa, NAKAMOTO Satoshi, YASAKA Yasuyoshi

  第6回日本電磁波エネルギー応用学会シンポジウム, Oct. 2012, 京都大学


• Examination on Plasma Production and Ion Heating for Electric Propulsion Using a Single Helical Antenna

  HAYASHI Yoshifumi, KINOSHITA Ryosuke, WAKABAYASHI Haruki, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi

  Joint Conf. 9th Int. Conf. Open Magnetic Systems for Plasma Confinement and 3rd Int. Workshop on Plasma Material Interaction Facilities for Fusion, Aug. 2012, Epochal Tsukuba


• Basic Characteristics of Secondary Electron Emission from Foil Electrodes for New Energy Recovery Scheme of High Energy Ions in an Advanced Fusion

  AKASHI Daisuke, TAKESHITA Yousuke, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, FURUYAMA Yuichi, TANIIKE Akira

  Joint Conf. 9th Int. Conf. Open Magnetic Systems for Plasma Confinement and 3rd Int. Workshop on Plasma Material Interaction Facilities for Fusion, Aug. 2012, Epochal Tsukuba


• 箔電極からの2 次電子放出を利用した高エネルギーイオンのエネルギー回収実験

  AKASHI Daisuke, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, KITAMURA Akira, TANIIKE Akira

  第9回核融合エネルギー連合講演会, Jun. 2012, 神戸国際会議場


• Studies on Plasma Production and Acceleration Using Rotating Electromagnetic Fields for Electrical Propulsion Engine

  WAKABAYASHI Haruki, HAYASHI Yoshifumi, NAKAMOTO Satoshi, YASAKA Yasuyoshi, TAKENO Hiromasa

  The 21st International Toki Conference, Nov. 2011, National Institute for Fusion Science, 土岐


• 箔電極からの2次電子放出を利用した高エネルギーイオンのエネルギー回収に関する研究

  AKASHI Daisuke, TOKUMA Satoshi, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, KITAMURA Akira, TANIIKE Akira

  2011 Kansai-section Joint Convention of Institutes of Electrical Engineering, Oct. 2011, 電気関係学会関西支部, 姫路


• 空洞共振器を利用したハイパーサーミア構成のためのFDTD法による電界分布の数値解析

  OKAMOTO Kazuya, TAKENO Hiromasa, NAKAMOTO Satoshi, YASAKA Yasuyoshi

  2011 Kansai-section Joint Convention of Institutes of Electrical Engineering, Oct. 2011, 電気関係学会関西支部, 姫路


• 回転電磁界を用いたプラズマの生成と加熱に関する研究

  HAYASHI Yoshifumi, WAKABAYASHI Haruki, NAKAMOTO Satoshi, YASAKA Yasuyoshi, TAKENO Hiromasa

  2011 Kansai-section Joint Convention of Institutes of Electrical Engineering, Oct. 2011, 電気関係学会関西支部, 姫路


• 電気推進エンジンのための高周波回転電磁界型アンテナを用いたプラズマ生成及び加熱制御に関する研究

  YAMAMOTO Masanori, WAKABAYASHI Haruki, YASAKA Yasuyoshi, NAKAMOTO Satoshi

  The Japan Society of Plasma Science and Nuclear Fusion Research 27th Annual Meeting, Nov. 2010, プラズマ・核融合学会, 札幌


• 回転電磁界型電気推進エンジンにおけるプラズマの生成と加速に関する研究

  WAKABAYASHI Haruki, YAMAMOTO Masanori, NAKAMOTO Satoshi, YASAKA Yasuyoshi, TAKENO Hiromasa

  2010 Kansai-section Joint Convention of Institutes of Electrical Engineering, Nov. 2010, 電気関係学会関西支部, 草津


• Rotating RF System for Novel Control of a Magnetoplasma Thruster

  YASAKA Yasuyoshi, NAKAMOTO Satoshi, NISHINO Satoshi, TAKENO Hiromasa, YONEMORI Hideto

  The 8th International Conference on Open Magnetic Systems for Plasma Confinement, Jul. 2010, Budker Institute of Nuclear Physics, ノボシビリスク


• Fundamental Study on Low Invasive Hyperthermia Using Long-wavelength Microwave IV

  TAKENO Hiromasa, TABATA Youhei, NAKAMOTO Satoshi, YASAKA Yasuyoshi, MITANI Tomohiko, SHINOHARA Masaki, NAMIKI Hironori

  The 28th meeting of IEICE Technical Committee on Solar Power Satellite/Station, Mar. 2010, 京都大学生存圏研究所METLAB共同利用専門委員会, 宇治


• 高エネルギーイオンビームからの新しいエネルギー回収法の基礎実験

  YAMAMOTO Masanori, NISHIKURA Takashi, UTSUMI Takahiro, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, KITAMURA Akira, TANIIKE Akira

  2009 Kansai-section Joint Convention of Institutes of Electrical Engineering, Nov. 2009, 電気関係学会関西支部, 吹田


• Fundamental Studies of Non-invasive Hyperthermia Using an Inclined Antenna Array Applicator with Phase Control

  TABATA Youhei, NAKAMOTO Satoshi, TAKENO Hiromasa, YASAKA Yasuyoshi, MITANI Tomohiko, SHINOHARA Masaki, NAMIKI Hironori

  第3回日本電磁波エネルギー応用学会シンポジウム, Nov. 2009, 日本電磁波エネルギー応用学会, 東京


• Fundametal Study on Low Invasive Hyperthermia Using Long-wavelength Microwave

  TAKENO Hiromasa, MATSUMOTO Hiroshi, ISHIDA Hiroki, NAKAMOTO Satoshi, YASAKA Yasuyoshi, KAWAI Shigeaki, MITANI Tomohiko, SHINOHARA Masaki, NAMIKI Hironori

  The 16th Meeting of The Institute of Electronics, Information and Communication Engineers of Japan Technical Committee on Solar Power Satellite Station, Feb. 2007, 京都大学生存圏研究所METLAB共同利用専門委員会, 宇治市


• Analysis of Microwave Propagationfor Infrared Thermography Method Using Microwave Heating

  TAKENO Hiromasa, NISHIKAWA Norimitsu, NAKAMOTO Satoshi, YASAKA Yasuyoshi, KOBAYASHI Yuki, TSUJI Masanori, NAMIKI Hironori

  The 55th the Society of Material Science, Japan Annual Meetings, May 2006, 日本材料学会, 長岡市

• 電気学会

• Studies on temporal variation analysis of modulation effect and self-excitation in a traveling wave direct energy converter

  竹野 裕正, 古川 武留, 中本 聡, 市村 和也

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 01 Apr. 2020 - 31 Mar. 2024

  令和3年度は，11月に新たに古川を研究分担者として加え，前年度からの人的資源の不足を補うことができた．当初組織の市村とは専門領域は必ずしも同じではないが，竹野の役割を調整することにより，課題全体としての効率的な推進を図った．前年度に引き続き，内容は3つの副課題に分けて行った． 1) 副課題1：可変径大口径イオン源の製作では，前年度の概略設計に基づいて精密設計を行い，主要部品のターボ分子ポンプと空芯磁場コイルとを中心として，多数の小部品を設計・製作依頼した．しかし，社会情勢・国際情勢の影響を受け，空芯磁場コイルの部材調達には想定外の時間を要した．また，小部品の製作では，やはり社会情勢・国際情勢の影響で原材料価格が高騰したため当初想定予算が圧迫され，部品調達計画の見直しが必要となった．これらによって，年度内に製作予定であった大口径イオン源は完成できず，次年度へ持ち越すこととなった． 2) 副課題2：径方向散乱に注目した変調効果時間変化の模擬実験解析においては，ガス圧と高周波電力の調整により，ビーム電流の飛躍的な増大を達成した．これにより，径方向散乱の測定の見通しが得られた．一方，荷電交換による中性粒子の発生が測定に影響していることが確認された．これについては，問題を回避する条件を探る必要がある． 3) 副課題4：模擬実験結果の数値解析においては，拡張の元とする既存コードを現状実験に合わせて実行していたところ，磁場印加下で疑問のあるイオン軌道を見いだした．現時点で原因が確認できていない．


• 核融合直接発電のためのカスプ型－進行波型統合システムの研究

  竹野 裕正

  科学研究費補助金／基盤研究(B), Apr. 2016 - Mar. 2019

  Competitive research funding


• 核融合直接発電のための高周波電界を用いた荷電粒子分離改善法の研究

  竹野 裕正

  学術研究助成基金助成金／基盤研究(C), Apr. 2013 - Mar. 2016

  Competitive research funding


• シミュレータ実装制御システムを備えた次世代プロセス用プラズマ源の研究

  八坂 保能

  科学研究費補助金／基盤研究(B), 2011

  Competitive research funding


• 進行波型直接エネルギー変換器における変調方式の実験研究

  竹野 裕正

  科学研究費補助金／基盤研究(C), 2010

  Competitive research funding


• 模擬実験による進行波型直接エネルギー変換器の自励発振の研究

  竹野 裕正

  科学研究費補助金／基盤研究(C), 2007

  Competitive research funding


• CHARACTERISTICS OF TIME-EVOLUTION OF LASER-PRODUCED PLASMA IN WATER VAPOR

  ARAI Kenji, CHO Mengu, NAKAMOTO Satoshi, TAKENO Hiromasa

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1994 - 1995

  As a fundamental research of extinction of lightning, which is the advanced scheme of laser-induced lightning, we have experimentally investigated the characteristics of time-evolution of laser-produced plasma in water vapor for two years. The experiments have been carried out from two kinds of aspects, and we have obtained following results. 1. The time-evolution of the radiation of the plasma is measured with resolving into its wavelength components, and obtained each spectrum is analyzed. Just after the ignition, the continuous spectra are analyzed, and we have obtained the electron temperature of 5000-7000K.After a long period of time (over 10musec) , line spectra are enalyzed, and we have found the electron density of 10^<22>-10^<23>m^<-3> and decay time constant of 8musec. The remained problems are the reliability of the value of electron density by the analysis of continuous spectra and the unknown electron temperature in a long period of time. 2. We have examined the characteristics of plasma by applying a weak electric field. The amount of electric charge drawing from the plasma is proportional to the electric field strength and inversely proportional to the distance between electrodes. In order to examine the time variation, the pulsed electric field is applied. The results suggest that the shock wave produced with the plasma and/or water vapor affect the motion of the charged particles. A precise model is necessary to interpret the results and to know the plasma characteristics, but the present model just explains partial results, and it is insufficient for complete explanation. More experimental data are needed. Some problems are remained, but we have obtained the initial data for the farseeing aim of the extinction of lightning.


• Fundamental Study due to Quantitative Measurement of Light Emission from Induced Discharge in Cloud

  ARAI Kenji, MIYAHARA Ichinori, NAKAMOTO Satoshi, TAKENO Hiromasa

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1992 - 1993

  The purpose of this project is to clarify various characteristics of laser produced plasma to trigger lightning in cloud. The results are as follows. The experiment is performed by using water vapor as a target for the plasma production. The threshold laser energy for plasma production is reduced by 1/3 in this conditon. Using the optical image processing system for discharge light measurements, which consists of an image converter camera and a CCD camera, the spatial distributions of light emission from laser produced plasma and their temporal developments are successfully measured. The analyzing programs for these experimental data are newly coded on the usual personal computers and the engineering work station. The expansion and decay phases are quantitatively evaluated by the result of analysis. On one hand, the numerical analysis, in which the shock wave induced by a point explosion is treated, is performed to clarify the physical mechanism. The calculated results are well agree with the experimental results. The behavior of the plasma in the phase after the laser energy deposition can be described by the characteristics of shock wave propagation. The experiment is developed to spectrum analysis of the light emission. The absolute intensity of light is measured in two dimensional space of time and wavelength. The calibration experiments of the measurement system are carried out to short-gap discharge in air SF_6, which show the effectiveness of the system. The measurement is applied to the laser produced plasma, and its density and temperature are estimated. The estimated values are similar with a report by other groups. The further experiments, the measurement of induced current in the weak electric field, are already started. The more detailed and reliable knowledge will be obtained by the synthetic analysis with the result of this project.


• Measurement of Impulse Discharge Light and Image Processing for the Quantitative Analysis

  ARAI Kenji, NAKAMOTO Satoshi, MIYAHARA Ichinori

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1990 - 1991

  An image measuring and processing system was constructed with a streak camera, a highly sensitive CCD camera and a micro computer. Applying impulse or AC voltage to a Point-to-plane electrodes, the temporal development of discharge light from the gap in air and SF_6 gas were measured using this system. As the results of digital data processing on these recorded light, spatiotemporal brightness distributions of the light and integrated brightness waves were derived for the basic research on the quantitative treatment of the discharge light intensity. On the other hand, emitted discharge light from a gap, which set to the nearest point from an insulator surface, in air and SF_6 gas and the spectrum distribution were measured using this system for development of detection system on the feeble discharge in the gas insulated substation. These results showed that there is remarkable differences on the extended distance of positive corona luminosity between air and SF_6 gas. The insulator surface have influence on the onset of corona and the path of positive streamer discharge in air, but the effect is rather weak in the case of SF_6 gas. The measured results on the spectrum distribution indicated that there is some difference between the gap discharge and the surface discharge in the case of air, but the remarkable difference could not recognized in the case of SF_6 gas. These measured light intensity can be expressed by the brightness number, but the number is affected by the various measuring conditions and the characteristics of used apparatus. For the quantitative study of discharge phenomena, it is needed to make clear the relationship between the brightness number and the density of emitted photons. Therefore, a halogen standard lamp were used as the calibration source for the used image measuring and processing system and the number of emitted photons in the short gap discharge were derived.


• Diagnostic Measurement in GIS based on Frequency Analysis of Partial Discharge in SF_6 Gas

  ARAI Kenji, NAKAMOTO Satoshi, FUJIOKA Nobuhiro

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Faculty of Engineering, Kobe University, 1987 - 1988

  To investigate the fundamental properties about the detection of abnormal discharge in GIS, short-gapdischarge phenomena were studied in air and SF_6 gas. The results can be summarized as follows: (1) In the spark-type discharge, pulse width of the current wave shape is several nano seconds, and the peak value of it is several amperes. In this case, the radiated electromagnetic wave, of which frequency spectrum extends to more wider than 1 GHz, is strong enough to be detected with an antenna. in the corona-type discharge, the peak value of the current wave shape is smaller than several milli amperes, and the level of its radiated electromagnetic wave is comparable to that of the background noise. Therefore, it is more difficult to detect the corona-type discharge than the spark-type short gap discharge. (2) Current wave shape of the corona-type discharge in SF_6 gas is remarkably different from that in air. The wave tail is about 2 nano seconds in SF_6 gas, and the one in air is several ten nano seconds. To clear the cause of these differences, a calculation of a single electron avalanche model was carried out. In SF_6 gas, negative ion cloude of high density is produced very near the tip of the negative needle, in a time shorter than 1 nano second after the generation of trigger electron. In air, the negative ion cloud of low density is produced at a distance from the tip of the negative needle. Therefore, it can be saide that suppression of the discharge requires repetition of many avalanche developments in air, and as the result the wave tail of the discharge current is longer. (3) The digital processing of the frequency spectrum constitutes an effective way to detect the corona-type discharge. In this way it is possible to detect a positive corona discharge of several ten pico Coulombs. On the other hand, detection of a negative corona discharge is difficult even with digital processing, due to small charge pulse, and more studies are required.