無衝突ワイベル衝撃波による粒子加速に関する研究

• Project/Area Number: 19J20765
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Review Section: Basic Section 14010:Fundamental plasma-related
• Research Institution: Osaka University
• Principal Investigator: 太田 雅人 大阪大学, 理学研究科, 特別研究員(DC1)
• Project Period (FY): 2019-04-25 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥3,400,000 (Direct Cost: ¥3,400,000); Fiscal Year 2021: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2020: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2019: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: 相対性理論 / レーザープラズマ / テラヘルツ / 宇宙物理学 / 非線形光学 / X線自由電子レーザー / 宇宙線 / 無衝突衝撃波 / E-Oサンプル / X線自由電レーザー

Outline of Research at the Start

宇宙の起源として希薄なプラズマにおける無衝突衝撃波加速が有力視されている．加速機構として，衝撃波の上下流の乱流電磁場によって荷電粒子が反射されて衝撃波面を何度も往復しながらエネルギーを増す統計加速が提唱されている．本研究では，高強度レーザー生成高速プラズマを用いて，自己生成乱流磁場が散逸機構を担う無衝突ワイベル衝撃波の実験を行う． X線自由電子レーザーによるワイベル衝撃波生成過程で生じる電流フィラメントの時間・空間発展の可視化と新たに作製する時間分解式荷電粒子エネルギースペクトロメータを用い統計加速による荷電粒子の非熱的エネルギー成分の時間発展を計測し,宇宙線の加速機構を実験的に明らかにする.

Outline of Annual Research Achievements

申請者はX線自由電子レーザー(XFEL)を用いたプラズマ密度計測実験とElectro-Optic(EO)サンプリングによる超高速電場計測実験を実施した。前者に関しては、理化学研究所のXFEL（パルス幅<10 fs）と併設する高強度短パルス(HI)レーザー（レーザー強度10^18W/cm^2）を用いたポンプ・プローブ実験を行った。HIレーザーを固体に照射し生成されたプラズマに対して、X線小角散乱法を用いることでサブピコ秒、サブナノメートルスケールの三次元的プラズマ膨張の時間発展を計測することに成功した。後者に関しては、相対論的電子ビーム（エネルギー35MeV、パルス幅1ピコ秒）周りに生成される特徴的な電場時空間分布（進行方向への空間的収縮）をEOサンプリングによって計測した。特殊相対性理論が理論的に確立されて以来100年以上を経て、電磁場のローレンツ収縮を直接的に実証した。
申請者は、上記の研究に対して中心的な役割を担い、実験計画の立案、実験実施、実験解析を行った。申請者は研究成果を国内外の学会で発表を行い優秀賞を多数受賞しており、研究内容が高く評価されている。EOサンプリング実験で得られた一部の成果は既に論文化されている(M. Ota et al. APEX 14, 026503 (2021), M. Ota et al. Proc. SPIE 11906 IRMMW (2021))。当初の最終研究目的である「レーザープラズマ実験によるWeibel衝撃波の実証」に向けた計測器開発（XFELを用いたX線小角散乱法、EOサンプリング）は達成し、目標とする実験の見通しが立った。

Research Progress Status

令和3年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和3年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest (2022)
  • Author(s): Yamazaki R.、Matsukiyo S.、Morita T.、Tanaka S. J.、Umeda T. et al. (54 authors)
  • Journal Title: Physical Review E Volume: 105 Issue: 2 Pages: 025203-025203
  • DOI: 10.1103/physreve.105.025203
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Robustness of large‐area suspended graphene under interaction with intense laser (2022)
  • Author(s): Y. Kuramitsu, T. Minami, T. Hihara, K. Sakai, T. Nishimoto, S. Isayama, Y.T. Liao, K.T. Wu, W.Y. Woon, S.H. Chen, Y.L. Liu, S.M. He, C Y. Su, M. Ota, S. Egashira, A. Morace, Y. Sakawa, H. Habara, R. Kodama, L.N.K. Dohl, N. Woolsey, M. Koenig, M. Kanasaki, T. Asai, T. Yamauchi, K. Oda, Ko. Kondo, H. Kiriyama, Y. Fukuda
  • Journal Title: Scientific Reports Volume: 12 Issue: 1 Pages: 2346-2346
  • DOI: 10.1038/s41598-022-06055-4
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Longitudinal and transverse spatial beam profile measurement of relativistic electron bunch by electro-optic sampling (2021)
  • Author(s): Masato Ota, Koichi Kan, Soichiro Komada, Yasunobu Arikawa, Tomoki Shimizu, Valynn Katrine Mag-usara, Youichi Sakawa, Tatsunosuke Matsui, and Makoto Nakajima
  • Journal Title: Applied Physics Express Volume: 14 Issue: 2 Pages: 026503-026503
  • DOI: 10.35848/1882-0786/abd867
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest (2021)
  • Author(s): Takayoshi Sano, et al.
  • Journal Title: PHYSICAL REVIEW E Volume: 105 Issue: 3 Pages: 1-16
  • DOI: 10.1103/physreve.104.035206
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Probing ultrafast laser plasma processes inside solids with resonant small-angle x-ray scattering (2021)
  • Author(s): Lennart Gaus , et al.
  • Journal Title: PHYSICAL REVIEW RESEARCH Volume: 3 Issue: 4 Pages: 1-11
  • DOI: 10.1103/physrevresearch.3.043194
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Ultrafast visualization of an electric field around relativistic electron beams (2021)
  • Author(s): M. Ota, K. Kan, S. Komada, Y. Arikawa, V. C. Agulto, V. K. Mag-usara, Y. Sakawa, T. Matsui, and M. Nakajima
  • Journal Title: Proc. SPIE Volume: 11906 Pages: 1-6
  • DOI: 10.1117/12.2601103
• [Journal Article] Local plasma parameter measurements in colliding laser-produced plasmas for studying magnetic reconnection (2020)
  • Author(s): Morita T.、Tomita K.、Sakai K.、Takagi M.、Aihara K.、Edamoto M.、Egashira S.、Higuchi T.、Ishizaka N.、Izumi T.、Kakuchi S.、Kojima T.、Kuramitsu Y.、Matsukiyo S.、Nakagawa Y.、Minami T.、Murakami H.、Nishioka Y.、Ota M.、Sano T.、Sei S.、Sugiyama K.、Tanaka S.J.、Yamazaki R.、Sakawa Y.
  • Journal Title: High Energy Density Physics Volume: 36 Pages: 100754-100754
  • DOI: 10.1016/j.hedp.2020.100754
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Observation of ultra-high energy density state with x-ray free electron laser SACLA (2020)
  • Author(s): Y. Maeda , Y. Hironaka , T. Iwasaki , K. Kawasaki , Y. Sakawa , T. Izumi , M. Ota , S. Egashira ,Y. Nakagawa, N. Higashi, Y. Sentoku, R. Kodama, N. Ozaki, T. Matsuoka, T. Somekawa, T. Yabuuchi, Y. Inubushi, T. Togashie, A. Kone, K. Sueda, K. Miyanishi, S. Shingubara, T. Shimizu, A. Okumura, K. Shigemori
  • Journal Title: High Energy Density Physics Volume: 36 Pages: 100813-100813
  • DOI: 10.1016/j.hedp.2020.100813
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Collisionless electrostatic shock acceleration of proton using high intensity laser (2019)
  • Author(s): Ota M.、Morace A.、Kumar R.、Kambayashi S.、Egashira S.、Kanasaki M.、Fukuda Y.、Sakawa Y.
  • Journal Title: High Energy Density Physics Volume: 33 Pages: 100697-100697
  • DOI: 10.1016/j.hedp.2019.100697
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Laboratory Observation of Radiative Shock Deceleration and Application to SN 1987A (2019)
  • Author(s): Michel Th.、Albertazzi B.、Mabey P.、Rigon G.、Lefevre F.、Van Box Som L.、Barroso P.、Egashira S.、Kumar R.、Michaut C.、Ota M.、Ozaki N.、Sakawa Y.、Sano T.、Falize E.、Koenig M.
  • Journal Title: The Astrophysical Journal Volume: 888 Issue: 1 Pages: 25-25
  • DOI: 10.3847/1538-4357/ab5956
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Anomalous plasma acceleration in colliding high-power laser-produced plasmas (2019)
  • Author(s): 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, and Y. Sakawa
  • Journal Title: Physics of Plasmas Volume: 26 Issue: 9 Pages: 090702-090702
  • DOI: 10.1063/1.5100197
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Longitudinal and transverse spatial beam profile measurement of relativistic electron bunch by electro-optic sampling (2021)
  • Author(s): Masato Ota et al.
  • Organizer: 10th Advanced Lasers and Photon Sources Conference
  • Int'l Joint Research
• [Presentation] Lorentz contraction of an electric field around relativistic electron beams (2021)
  • Author(s): Masato Ota et al.
  • Organizer: The 46th International Conference on Infrared, Millimeter and Terahertz Waves
  • Int'l Joint Research
• [Presentation] Study of the spatio-temporal profile diagnostics for relativistic picosecond electron bunches by electro-optic sampling (2021)
  • Author(s): Masato Ota et al.
  • Organizer: The 46th International Conference on Infrared, Millimeter and Terahertz Waves
  • Int'l Joint Research
• [Presentation] Electro-Optic Detection for Terahertz Electric Field Contraction around Relativistic Electron Beams (2021)
  • Author(s): Masato Ota et al.
  • Organizer: 日本応用物理学会秋季大会2021
• [Presentation] 相対論的電子ビーム電場の超高速時空間分布計測 (2021)
  • Author(s): Masato Ota et al.
  • Organizer: 日本物理学会秋季大会2021
• [Presentation] Ultrafast visualization of an electric field around relativistic electron beams (2021)
  • Author(s): Masato Ota et al.
  • Organizer: The international society for optics and photonics ASIA 2021
  • Int'l Joint Research / Invited
• [Presentation] Longitudinal and transverse spatial beam profile measurement of relativistic electron bunch by electro-optic sampling (2021)
  • Author(s): 太田雅人
  • Organizer: The 10th Advanced Lasers and Photon Sources
  • Int'l Joint Research
• [Presentation] SACLAを用いたサブミクロンロッド集合体ターゲットのX 線小角散乱実験 (2020)
  • Author(s): 太田雅人
  • Organizer: 日本物理学会
• [Presentation] EO サンプリングを用いた相対論的電子バンチの 縦横方向電荷密度同時計測 (2020)
  • Author(s): 太田雅人
  • Organizer: プラズマ・核融合学会年会
• [Presentation] Small Angle X-ray Scattering on Rod Assembly Target at SACLA (2020)
  • Author(s): M. Ota, M. Rodel, S. Egashira, T. Izumi, Y. Nakagawa, T. Pikuz, A. S. Pirozhkov, A. Laso Garcia, A. Morace, T. Minami, K. Sakai, Y. Fukuyama, Y. Maeda, H. Takabe, T. E. Cowan, M. Nakatsutsumi, K. Fukami, T. Kluge, Y. Fukuda, Y. Kishimoto, and Y. Sakawa
  • Organizer: First experiments with a high-intensity short-pulse laser at HED/HIBEF
  • Int'l Joint Research / Invited
• [Presentation] Small angle X-Ray Scattering with Sub-Micron Rod-assembly Target at SACLA (2019)
  • Author(s): M. Ota, M. Rodel, S. Egashira, T. Izumi, T. Pikuz, A. S. Pirozhkov, A. Laso Garcia, A. Morace, T. Minami, Y. Fukuyama, Y. Maeda, B. Albertazzi, M. Koenig, K. Shigemori, Y. Sentoku, H. Takabe, T. E. Cowan, M. Nakatsutsumi, T. Kluge, Y. Fukuda, K. Fukami, Y. Kishimoto and Y. Sakawa
  • Organizer: 11th International Conference on Inertial Fusion Science and Applications