Ｎｅｗ ｈｉｇｈ ｈａｒｍｏｎｉｃ ｇｅｎｅｒａｔｉｏｎ ｍｅｃｈａｎｉｓｍ

2011 Fiscal Year Research-status Report

• Project/Area Number: 23740413
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: PIROZHKOV Alex 独立行政法人日本原子力研究開発機構, 量子ビーム応用研究部門, 研究職 (00446410)
• Project Period (FY): 2011-04-28 – 2014-03-31
• Keywords: コヒーレントx線放射 / レーザー光の高次高調波 / レーザー光とプラズマの相互作用 / 超高強度レーザー / 相対論的プラズマ

Research Abstract

2011年度は、新しい高次高調波生成に関する研究は大きく進捗した。まず、原子力機構にて高次高調波生成の実験を行ない、高次高調波の角度分布やコヒーレンス、光源サイズの実験データを取得した。さらに高次高調波の強度が以前の実験よりも向上し、高い光子エネルギー（500 eV以上、以前は360 eV）も実現させることができた。2011年度に得られた実験データは、大変重要で興味深いものであり、この知見によって新しい高次高調波生成の理解は大きく進むといえる。現在の高次高調波の角度分布のスペクトルデータをシングルショットで計測するために、3チャンネルのフラットフィールド分光器を設計し、製作を開始した。これにより、高次高調波の分布のより詳細なデータが取得できる。高次高調波生成に関する最初の論文をPhysical Review Letters誌に発表した [A. S. Pirozhkov, et al., "Soft-X-Ray Harmonic Comb from Relativistic Electron Spikes," Phys. Rev. Lett. 108 (13), 135004-5 (2012)]。また、この成果をプレス発表し、朝日新聞に掲載された（3月15日朝刊）。4つの国際学会と1つの国内の学会にて、3件の招待講演を行ない、2件の口頭発表を行った。この2011年度に得られた成果は、小型レーザーで利用しやすい、デブリのでないガスジェットターゲットを用いた、次世代の小型コヒーレントX線源としての道を切り開くものである。本研究の成果は、重要で社会的にも高いインパクトがあるので、この新しいX線源とそれを用いた応用研究を迅速に進めるためには、大規模な研究展開が望まれる。

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

The progress is extremely good. Within plan, I obtained experimental data on harmonics coherence and source size, and, above plan, on angular distribution. In 2011 experiment the spectra were much brighter and reaching higher photon energy: >500eV now, 360eV previously.Within plan, I designed and ordered parts of 3-channel x-ray spectrograph. Above plan, I learned alignment and operation of such device with collaborators from Rutherford Appleton Laboratory, UK.I published results in PRL (JAEA press release 3 Mar, article朝日新聞15 Mar 2012), made 5 presentations [3 invited] in 4 international &1 domestic conferences.

Strategy for Future Research Activity

The data obtained in the FY 2011 are extremely important and interesting, it will provide new information on the novel harmonics generation regime. I will perform careful data analysis and publish the results in high-impact factor journals.I will buy the remaining parts of the 3-channel flat-field spectrograph and assemble it.I will perform further experiments to elucidate properties of the harmonics x-ray source.

Expenditure Plans for the Next FY Research Funding

I am going to use this year's budget (800,000 yen) and the money transfered from the previous year (8,501 yen), the total is 808,501 yen.I am going to participate in the international conference (ELI workshop), this will cost about 300,000 yen.I will use the rest of the money to the remaining parts of the 3-channel flat-field spectrograph (~500,000 yen).

Research Products

• [Journal Article] Soft-X-Ray Harmonic Comb from Relativistic Electron Spikes (2012)
  • Author(s): A. S. Pirozhkov, M. Kando, T. Zh. Esirkepov, P. Gallegos, H. Ahmed, E. N. Ragozin, A. Ya Faenov, T. A. Pikuz, T. Kawachi, A. Sagisaka, J. K. Koga, M. Coury, J. Green, P. Foster, C. Brenner, B. Dromey, D. R. Symes, M. Mori, K. Kawase, T. Kameshima, Y. Fukuda, L. Chen, I. Daito, K. Ogura, Y. Hayashi, H. Kotaki, H. Kiriyama, H. Okada, N. Nishimori, T. Imazono, K. Kondo, T. Kimura, T. Tajima, H. Daido, P. Rajeev, P. McKenna, M. Borghesi, D. Neely, Y. Kato, and S. V. Bulanov
  • Journal Title: Phys. Rev. Lett Volume: 108(13) Pages: 135004-5
  • DOI: 10.1103/PhysRevLett.108.135004
  • URL: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.135004
  • Peer Reviewed
• [Journal Article] Coherent x-ray generation in relativistic laser/gas jet interactions (2011)
  • Author(s): A. S. Pirozhkov, M. Kando, T. Zh. Esirkepov, P. Gallegos, H. Ahmed, E. N. Ragozin, A. Ya. Faenov, T. A. Pikuz, J. K. Koga, H. Kiriyama, P. McKenna, M. Borghesi, K. Kondo, H. Daido, Y. Kato, D. Neely, and S. V. Bulanov
  • Journal Title: Proc. SPIE (Proc. Int. Conf. X-Ray Lasers and Coherent X-Ray Sources : Development and Applications IX, Optics+Photonics Symposium, San Diego, USA, 23-25 August 2011, ed. J. Dunn and A. Klisnick) (Refereed proceedings paper) Volume: 8140 Pages: 81400A-16
  • DOI: 10.1117/12.892898
  • Peer Reviewed
• [Presentation] High-Order Harmonic Generation in Gas Jet Targets by Relativistic Irradiance Lasers (2012)
  • Author(s): A. S. Pirozhkov
  • Organizer: Spring Meeting of The Physical Society of Japan
  • Place of Presentation: Kwansei Gakuin University, Japan
  • Year and Date: 25 March 2012
• [Presentation] High-order harmonic generation in gas jet targets in the relativistic laser-plasma interaction regime (2011)
  • Author(s): A. S. Pirozhkov
  • Organizer: Plasma 2011
  • Place of Presentation: Ishikawa, Kanazawa, Japan
  • Year and Date: 25 November 2011
• [Presentation] Coherent X-ray generation in relativistic laser - gas jet interactions (2011)
  • Author(s): A. S. Pirozhkov
  • Organizer: X-Ray Lasers and Coherent X-Ray Sources: Development and Applications, part of SPIE Optics+Photonics(招待講演)
  • Place of Presentation: San Diego, California, US
  • Year and Date: 23 August 2011
• [Presentation] Relativistic high harmonic generation in gas jet targets (2011)
  • Author(s): A. S. Pirozhkov
  • Organizer: The 3rd International Symposium "Laser-Driven Relativistic Plasmas Applied to Science, Energy, Industry, and Medicine"(招待講演)
  • Place of Presentation: Kizugawa, Kyoto, Japan
  • Year and Date: 2 June 2011
• [Presentation] New Coherent X-Ray Source Based on Relativistic High Harmonic Generation in Gas Jet Targets (2011)
  • Author(s): A. S. Pirozhkov
  • Organizer: III International Symposium "Topical Problems of Biophotonics - 2011"(招待講演)
  • Place of Presentation: St. Petersburg - Nizhny Novgorod, Russia
  • Year and Date: 18 July 2011
• [Remarks] JAEA press release about my paper in Physical Review Letters:
  • URL: http://www.jaea.go.jp/02/press2011/p12030201/index.htmlSupplemental
• [Remarks] material of PRL:
  • URL: http://prl.aps.org/supplemental/PRL/v108/i13/e135004