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NAKAMOTO SatoshiGraduate School of Engineering / Department of Electrical and Electronic EngineeringResearch Associate
Research activity information
■ Paper- 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)Scientific journal
- Japan Society of Plasma Science and Nuclear Fusion Research, Jun. 2023, Plasma and Fusion Research, 18, 2405053 - 2405053Scientific journal
- Japan Society of Plasma Science and Nuclear Fusion Research, Jul. 2020, Plasma and Fusion Research, 15, 2405046 - 2405046Scientific journal
- Feb. 2019, Plasma and Fusion Research, 14, 2405027, EnglishAnalytical Experiment of Time Evolution of Deceleration Effect in Traveling Wave Direct Energy Converter Using Dual-Frequency Modulation[Refereed]Scientific journal
- Japan Society of Plasma Science and Nuclear Fusion Research, 2019, Plasma and Fusion Research, 14, EnglishScientific journal
- Jan. 2019, Plasma and Fusion Research, 14, 2405013, EnglishRecent Advancement of Research on Plasma Direct Energy Conversion[Refereed]Scientific journal
- Nov. 2018, Fusion Engineering and Design, 136, 157 - 161, EnglishPerformance improvement due to additional collectors in a secondary electron direct energy converter simulator[Refereed]Scientific journal
- Nov. 2018, Fusion Engineering and Design, 136, 381 - 385, EnglishDevelopment of calorimeter system for conceptual study of CuspDEC divertor[Refereed]Scientific journal
- May 2018, Plasma and Fusion Research, 13, 3405050, EnglishMeasurement of Heat Quantity in a Small Cusp-Type Direct Energy Converter for Divertor Thermal Load Reduction[Refereed]Scientific journal
- Oct. 2016, Annual Report of National Institute for Fusion Science April2015-March2016, 454, EnglishCharge Separation Characteristics of a Newly Constructed CUSPDEC Device Using Permanent MagnetsResearch institution
- Japan Society of Plasma Science and Nuclear Fusion Research, 2016, Plasma and Fusion Research, 11(1) (1), 2405028 - 2405028, English[Refereed]Scientific journal
- Japan Society of Plasma Science and Nuclear Fusion Research, 2016, Plasma and Fusion Research, 11(1) (1), 2405029, English[Refereed]Scientific journal
- Japan Society of Plasma Science and Nuclear Fusion Research, 2016, Plasma and Fusion Research, 11(1) (1), 2405028, English[Refereed]Scientific journal
- Nov. 2015, Annual Report of National Institute for Fusion Science April2014-March2015, 469, EnglishExperimental Verification of Constant Deceleration of TWDEC for its MiniaturizationResearch institution
- Jul. 2015, FUSION SCIENCE AND TECHNOLOGY, 68(1) (1), 166 - 170, EnglishENHANCED ENERGY RECOVERY IN A SECONDARY ELECTRON DIRECT ENERGY CONVERTER THROUGH REDUCTION OF THE MAGNETIC MIRROR EFFECT[Refereed]Scientific journal
- Apr. 2015, Plasma and Fusion Research, 10, 3406032, EnglishStudies on Plasma Production and Ion Heating by Using Only a Single Helical Antenna for a Simple Thruster[Refereed]Scientific journal
- The Japan Society of Plasma Science and Nuclear Fusion Research, Mar. 2015, Plasma and Fusion Research, 10, 3405025 - 3405025, English
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.
[Refereed]Scientific journal - Dec. 2014, Collection of Papers for The 10th Internatinal Conference on Open Magnetic System for Plasma Confinement, 90 - 93, EnglishFundamental Studies on Secondary Electron Direct Energy Converter with Magnetic FieldInternational conference proceedings
- Dec. 2014, Open Journal of Applied Sciences, 4(13) (13), 523 - 532, EnglishBi-Directional Excitation of Radio Frequency Waves Using a Helical Antenna in Non-Uniform Plasmas towards a Compact Magnetoplasma Thruster[Refereed]Scientific journal
- Dec. 2014, Collection of Papers for The 10th Internatinal Conference on Open Magnetic System for Plasma Confinement, 94 - 97, EnglishAnalysis of Particle Distribution due to Modulation in Traveling Wave Direct Energy ConverterInternational conference proceedings
- Nov. 2014, Proceedings of PLASMA2014, 18PB - 031, EnglishVariation of Charge Separation due to Radio Frequency Application in a Cusp-type Direct Energy ConverterInternational conference proceedings
- Jul. 2013, Proceedings of 31st International Conference on Phenomena in Ionized Gases, PS2 - 058, EnglishBi-directional excitation of ICRF waves in non-uniform plasmas towards a compact RF-driven magnetoplasma thruster[Refereed]International conference proceedings
- May 2013, FUSION SCIENCE AND TECHNOLOGY, 63(1T) (1T), 389 - 391, EnglishEXAMINATION ON PLASMA PRODUCTION AND ION HEATING FOR ELECTRIC PROPULSION USING A SINGLE HELICAL ANTENNA[Refereed]Scientific journal
- May 2013, FUSION SCIENCE AND TECHNOLOGY, 63(1T) (1T), 301 - 303, EnglishBASIC CHARACTERISTICS OF SECONDARY ELECTRON EMISSION FROM FOIL ELECTRODES FOR NEW ENERGY RECOVERY SCHEME OF HIGH ENERGY IONS IN AN ADVANCED FUSION[Refereed]Scientific journal
- Mar. 2012, JOURNAL OF PROPULSION AND POWER, 28(2) (2), 364 - 370, English[Refereed]Scientific journal
- Sep. 2011, Proc. 32nd Int'l. ElectricPropulsion Conf., IEPC-2011-057, EnglishBasic Experiment on a Magnetoplasma Thruster Driven by Phase-Controlled RFScientific journal
- Jan. 2011, Proceedings of 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, AIAA 2011-1072 (7pp), EnglishNovel Control of Magnetoplasma Thruster by Using a Rotating RF SystemInternational conference proceedings
- Oct. 2010, Abstract Book of 23rd IAEA Fusion Energy Conference, p. 476, EnglishImprovement of Cusp Type and Traveling Wave Type Plasma Direct Energy Converters Applicable to Advanced Fusion Reactor[Refereed]Scientific journal
- Nov. 2007, Proceedings of 2007 Japan-Korea Joint Symposium on Electrical Discharge and High Voltage Engineering, pp. 43-46, EnglishImprovement of an applicator for hyperthermia in long wavelength microwave using small loop antennasInternational conference proceedings
- Institute of Electrical Engineers of Japan, 2007, IEEJ Transactions on Electronics, Information and Systems, 127(11) (11), 3 - 1838, English[Refereed]Scientific journal
- 2004, Proceeding of The 2nd International Symposium on Sustainable Energy System, 147, EnglishEffective Destruction of Easy-break Concrete by Microwave Irradiation Using Heat at the Contact Point of Conducting Materials[Invited]International conference proceedings
- Nov. 2003, Proceedings of 2003 Japan-Korea Joint Symposium on Electrical Discharge and High Voltage Engineering., 205-208, EnglishStudies on Easy-break Concrete Heating due to Microwave Strong Field Created by Conducting MarerialInternational conference proceedings
- Aug. 2003, Proceedings of the ⅩⅢth International Symposium on High Voltage Engineering., CD-ROM,No.385, EnglishImprovement of spatial resolution on surface charge measurement by applying an artificial neural network to obtain instrument function.International conference proceedings
- 2009, 第24 回宇宙太陽発電時限研究専門委員会研究会, Japanese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?Summary national conference
- 日本材料学会, 2006, 学術講演会講演論文集, 55, 287 - 288, Japanese327 Analysis of Microwave Propagation for Infrared Thermography Method Using Microwave Heating
- 日本材料学会, 2005, 学術講演会講演論文集, 54, 173 - 174, Japanese603 Compaction of a Carbon-fiber Antenna for Easy-break Concrete
- 日本材料学会, 2004, 学術講演会講演論文集, 53, 509 - 510, Japanese818 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)
- 12 Dec. 2003, 電気学会研究会資料. ED, 放電研究会, 2003(239) (239), 71 - 76, JapaneseImprovement of Heating Efficiency of Easy-break Concrete due to Microwave Strong Field Formed at Sharp Edges of Conducting Material
- 07 Dec. 2000, 電気学会研究会資料. ED, 放電研究会, 2000(168) (168), 7 - 12, JapaneseDiagnosis of Insulation Degradation of DC-GIS Using Pulsating Voltage (III)
- 03 Dec. 1999, 電気学会研究会資料. ED, 放電研究会, 1999(189) (189), 73 - 78, JapaneseDiagnosis of Insulation Degradation of DC-GIS Using Pulsating Voltage (II)
- 05 Dec. 1997, 電気学会研究会資料. ED, 放電研究会, 1997(226) (226), 71 - 76, JapaneseAnalysis on Mechanism of Discharge Induction by Laser Produced Plasma in a Short Air Gap
- 17 Jun. 1997, 電気学会研究会資料. ED, 放電研究会, 1997(39) (39), 19 - 23, JapaneseAnalytical Experiments on Effect of Shock Wave to Laser Induced Discharge
- 電気学会, Nov. 1996, The Transactions of the Institute of Electrical Engineers of Japan. A, 116(11) (11), 959 - 963, EnglishResearch on the Degradation of Insulating Material by Feeble Discharge in SF_6 Gas due to the Quantitative Measurement of Discharge Light
- The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, Japanese, 吹田, Domestic conferenceEffect of low mirror ratio magnetic field in fast ion energy recovery method using secondary electron emissionPoster presentation
- 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, Japanese, 神戸, Domestic conference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Poster presentation
- The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, Japanese, 吹田, Domestic conferenceStudy of ion beam extraction and transport in the composite-plasma source for researches of direct energy converterPoster presentation
- The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, Japanese, 吹田, Domestic conferenceDependence of Antenna Position in a Simulation Experiment of Plasma Thruster Using a Single Helical AntennaPoster presentation
- The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, Japanese, 吹田, Domestic conferenceStudies on transport of ion beam in simulator of traveling wave direct energy converterPoster presentation
- The 35th annual meeting of The Japan Society of Plasma Science and Nuclear Fusion Research, Dec. 2018, Japanese, 吹田, Domestic conferenceStudies on Plasma Generation and RF Field Distribution Measurement on Variable Length Single Helical Antenna Type Plasma ThrusterPoster presentation
- The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, English, Toki, International conferenceImprovement of ion-ion separation and collection by modification of electrode structure in a cusp type direct energy converterPoster presentation
- The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, English, Toki, International conferenceImprovement of evaluation of heat quantity in a simulation experiment of divertor thermal load reduction by using a charge separation devicePoster presentation
- The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, English, Toki, International conferenceExperimental analysis on variation of the amount of particles passing through traveling wave direct energy converterPoster presentation
- The 27th International Toki Conference on Plasma and Fusion Research \& The 13th Asia Pacific Plasma Theory Conference, Nov. 2018, English, Toki, International conferenceEffect of axial gradient of magnetic field in a plasma source of a thruster simulator using a single helical antennaPoster presentation
- 12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, English, Tsukuba, International conferenceWorking characteristics of a combined plasma source for ion-ion separation experiments in direct energy conversionPoster presentation
- 12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, English, Tsukuba, International conferenceRecent advancement of research on plasma direct energy conversionKeynote oral presentation
- 12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, English, Tsukuba, International conferenceImprovement of electron collection using a magnetic field suppressing mirror effect in a secondary electron direct energy converter simulatorPoster presentation
- 12th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2018, English, Tsukuba, International conferenceAnalytical experiment of time evolution of deceleration effect in traveling wave direct energy converter using dual-frequency modulationPoster presentation
- The joint meeting of the 26th International Toki Conference and The 11th Asia Plasma and Fusion Association Conference, Dec. 2017, English, 土岐市, International conferenceMeasurement of Heat Quantity in a Small Cusp-type Direct Energy Converter for Divertor Thermal Load ReductionPoster presentation
- The joint meeting of the 26th International Toki Conference and The 11th Asia Plasma and Fusion Association Conference, Dec. 2017, English, 土岐市, International conferenceA Preliminary Study of Ion-Ion Separation in Cusp-type Direct Energy ConverterPoster presentation
- Plasma Conference 2017, Nov. 2017, Japanese, 姫路市, Domestic conferenceRadial Dependence of Ion Energy Distribution in a Simulation Experiment of Plasma Thruster Using a Single Helical AntennaPoster presentation
- Plasma Conference 2017, Nov. 2017, Japanese, 姫路市, Domestic conferenceStudies on Plasma Production Control by the Length of a Single Helical Antenna for a Simple Electric ThrusterPoster presentation
- 平成29年電気関係学会関西連合大会, Nov. 2017, Japanese, 東大阪市, Domestic conference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Oral presentation
- Plasma Conference 2017, Nov. 2017, Japanese, 姫路市, Domestic conferenceStudies on Scattering due to Field of Bunched Ions in a Traveling Wave Direct Energy Converter SimulatorPoster presentation
- 平成29年電気関係学会関西連合大会, Nov. 2017, Japanese, 東大阪市, Domestic conference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Poster presentation
- the 13th International Symposium on Fusion Nuclear Technology, Sep. 2017, English, 京都市, International conferenceDevelopment of Calorimeter System for a Conceptual Study of CuspDEC DivertorPoster presentation
- the 13th International Symposium on Fusion Nuclear Technology, Sep. 2017, English, 京都市, International conferenceAnalytical Experiments on Scattering of High Energy Ions in a Secondary Electron Direct Energy Converter SimulatorPoster presentation
- 平成28年電気関係学会関西連合大会, Nov. 2016, Japanese, 堺市, Domestic conference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Poster presentation
- 平成28年電気関係学会関西連合大会, Nov. 2016, Japanese, 堺市, Domestic conference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Oral presentation
- プラズマ・核融合学会第33回年会, Nov. 2016, Japanese, 仙台市, Domestic conferenceDevelopment of a Combined Plasma Source Simulating Helium 3 Fusion Reactor for Direct Energy ConversionPoster presentation
- プラズマ・核融合学会第33回年会, Nov. 2016, Japanese, 仙台市, Domestic conferenceRefinement of a Small Cusp-type Device to Reduce the Divertor Thermal Loads by Direct Energy ConversionPoster presentation
- 平成28年電気関係学会関西連合大会, Nov. 2016, Japanese, 堺市, Domestic conference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Oral presentation
- プラズマ・核融合学会第33回年会, Nov. 2016, Japanese, 仙台市, Domestic conferenceStudy on the measurement of ion heating effect by a single helical antenna for a simple thrusterPoster presentation
- 平成28年電気関係学会関西連合大会, Nov. 2016, Japanese, 堺市, Domestic conference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Oral presentation
- 平成28年電気関係学会関西連合大会, Nov. 2016, Japanese, 堺市, Domestic conference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Oral presentation
- 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, Japanese, つくば市, Domestic conferenceGAMMA 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Oral presentation
- 平成27年電気関係学会関西連合大会, Nov. 2015, Japanese, 寝屋川市, Domestic conference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Oral presentation
- 平成27年電気関係学会関西連合大会, Nov. 2015, Japanese, 寝屋川市, Domestic conference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Oral presentation
- プラズマ・核融合学会第32回年会, Nov. 2015, Japanese, 名古屋市, Domestic conferenceVariation of Particle Orbit due to Radio Frequency Field in a Cusp-type Direct Energy ConverterPoster presentation
- 25th International Toki Conference, Nov. 2015, English, Toki, Japan, International conferenceVariation in secondary electron collection and energy recovery concerning electrode angle in a high energy ion penetration schemePoster presentation
- 25th International Toki Conference, Nov. 2015, English, Toki, Japan, International conferenceStudies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversionPoster presentation
- 25th International Toki Conference, Nov. 2015, English, Toki, Japan, International conferenceStudies on power dependence of plasma production and ion heating by a single helical antenna for a simple thrusterPoster presentation
- 25th International Toki Conference, Nov. 2015, English, Toki, Japan, International conferenceImprovement of charge separation by increase of magnets in a PM-CuspDEC simulatorPoster presentation
- 平成27年電気関係学会関西連合大会, Nov. 2015, Japanese, 寝屋川市, Domestic conference2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Oral presentation
- 平成26年電気関係学会関西支部連合大会, Nov. 2014, Japanese, Ikoma, Domestic conference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Poster presentation
- 24th International Toki Conference, Nov. 2014, English, Toki, International conferenceStudies on Plasma Production and Ion Heating by Using Only a Single Helical Antenna for a Simple ThrusterPoster presentation
- 24th International Toki Conference, Nov. 2014, English, Toki, International conferenceCharacterization of Secondary Electron Collection with Magnetic Field for Energy Recovery from High Energy IonPoster presentation
- 平成26年電気関係学会関西支部連合大会, Nov. 2014, Japanese, Ikoma, Domestic conference2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Poster presentation
- The 10th International Conference on Open Magnetic Systems for Plasma Confinement, Aug. 2014, English, Daejeon, International conferenceStudies on Plasma Production and Ion Heating Using Bi-Directional Excitation of High Frequency Waves for Electric PropulsionPoster presentation
- 平成25年電気関係学会関西支部連合大会, Nov. 2013, Japanese, 寝屋川, Domestic conference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Poster presentation
- 9th General Scientific Assembly of the Asia Plasma and Fusion Association in 2013, Nov. 2013, English, Gyeongju, International conferenceStudy of Energy Recovery from High Energy Ions Using Secondary Electron Emission with Magnetic FieldPoster presentation
- 23rd International Toki Conference, Nov. 2013, English, Toki, International conferenceStudies on Plasma Production and Ion Heating Using High Frequency for Electric PropulsionPoster presentation
- 平成25年電気関係学会関西支部連合大会, Nov. 2013, Japanese, 寝屋川, Domestic conference2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Poster presentation
- 平成24年電気関係学会関西支部連合大会, Dec. 2012, Japanese, 関西大学, Domestic conference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)Poster presentation
- 平成24年電気関係学会関西支部連合大会, Dec. 2012, Japanese, 関西大学, Domestic conference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Poster presentation
- 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, Japanese, 京都大学, Domestic conference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Poster presentation
- Joint Conf. 9th Int. Conf. Open Magnetic Systems for Plasma Confinement and 3rd Int. Workshop on Plasma Material Interaction Facilities for Fusion, Aug. 2012, English, Epochal Tsukuba, International conferenceExamination on Plasma Production and Ion Heating for Electric Propulsion Using a Single Helical AntennaPoster presentation
- Joint Conf. 9th Int. Conf. Open Magnetic Systems for Plasma Confinement and 3rd Int. Workshop on Plasma Material Interaction Facilities for Fusion, Aug. 2012, English, Epochal Tsukuba, International conferenceBasic Characteristics of Secondary Electron Emission from Foil Electrodes for New Energy Recovery Scheme of High Energy Ions in an Advanced FusionPoster presentation
- 第9回核融合エネルギー連合講演会, Jun. 2012, Japanese, 神戸国際会議場, Domestic conference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Poster presentation
- The 21st International Toki Conference, Nov. 2011, English, National Institute for Fusion Science, 土岐, International conferenceStudies on Plasma Production and Acceleration Using Rotating Electromagnetic Fields for Electrical Propulsion EnginePoster presentation
- 2011 Kansai-section Joint Convention of Institutes of Electrical Engineering, Oct. 2011, Japanese, 電気関係学会関西支部, 姫路, Domestic conference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Poster presentation
- 2011 Kansai-section Joint Convention of Institutes of Electrical Engineering, Oct. 2011, Japanese, 電気関係学会関西支部, 姫路, Domestic conference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Poster presentation
- 2011 Kansai-section Joint Convention of Institutes of Electrical Engineering, Oct. 2011, Japanese, 電気関係学会関西支部, 姫路, Domestic conference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Poster presentation
- The Japan Society of Plasma Science and Nuclear Fusion Research 27th Annual Meeting, Nov. 2010, Japanese, プラズマ・核融合学会, 札幌, Domestic conference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Oral presentation
- 2010 Kansai-section Joint Convention of Institutes of Electrical Engineering, Nov. 2010, Japanese, 電気関係学会関西支部, 草津, Domestic conference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Poster presentation
- The 8th International Conference on Open Magnetic Systems for Plasma Confinement, Jul. 2010, English, Budker Institute of Nuclear Physics, ノボシビリスク, International conferenceRotating RF System for Novel Control of a Magnetoplasma ThrusterOral presentation
- The 28th meeting of IEICE Technical Committee on Solar Power Satellite/Station, Mar. 2010, Japanese, 京都大学生存圏研究所METLAB共同利用専門委員会, 宇治, Domestic conferenceFundamental Study on Low Invasive Hyperthermia Using Long-wavelength Microwave IVOral presentation
- 2009 Kansai-section Joint Convention of Institutes of Electrical Engineering, Nov. 2009, Japanese, 電気関係学会関西支部, 吹田, Domestic conference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Poster presentation
- 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, Japanese, 日本電磁波エネルギー応用学会, 東京, Domestic conferenceFundamental Studies of Non-invasive Hyperthermia Using an Inclined Antenna Array Applicator with Phase ControlOral presentation
- The 16th Meeting of The Institute of Electronics, Information and Communication Engineers of Japan Technical Committee on Solar Power Satellite Station, Feb. 2007, Japanese, 京都大学生存圏研究所METLAB共同利用専門委員会, 宇治市, Domestic conferenceFundametal Study on Low Invasive Hyperthermia Using Long-wavelength MicrowaveOral presentation
- The 55th the Society of Material Science, Japan Annual Meetings, May 2006, Japanese, 日本材料学会, 長岡市, Domestic conferenceAnalysis of Microwave Propagationfor Infrared Thermography Method Using Microwave HeatingOral presentation
■ Research Themes
- 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. 2024Studies on temporal variation analysis of modulation effect and self-excitation in a traveling wave direct energy converter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.
- 科学研究費補助金/基盤研究(B), Apr. 2016 - Mar. 2019Competitive research funding
- 学術研究助成基金助成金/基盤研究(C), Apr. 2013 - Mar. 2016Competitive research funding
- 科学研究費補助金/基盤研究(B), 2011Competitive research funding
- 科学研究費補助金/基盤研究(C), 2010Competitive research funding
- 科学研究費補助金/基盤研究(C), 2007Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1994 - 1995CHARACTERISTICS OF TIME-EVOLUTION OF LASER-PRODUCED PLASMA IN WATER VAPORAs 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.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1992 - 1993Fundamental Study due to Quantitative Measurement of Light Emission from Induced Discharge in CloudThe 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.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for General Scientific Research (C), Kobe University, 1990 - 1991Measurement of Impulse Discharge Light and Image Processing for the Quantitative AnalysisAn 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.
- 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 - 1988Diagnostic Measurement in GIS based on Frequency Analysis of Partial Discharge in SF_6 GasTo 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.