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High-order harmonic generation by relativistic plasma singularities
https://repo.qst.go.jp/records/73305
https://repo.qst.go.jp/records/733055f5391c4-7c1a-48a8-9917-4804c400ba51
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2017-12-20 | |||||
| タイトル | ||||||
| タイトル | High-order harmonic generation by relativistic plasma singularities | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
ピロジコフ, アレキサンダー
× ピロジコフ, アレキサンダー× エシロケポフ, ティムル× A., Pikuz T.× Ya., Faenov A.× 小倉, 浩一× 林, 由紀雄× 小瀧, 秀行× N., Ragozin E.× Neely, D.× 桐山, 博光× コーガ, ジェームズ× 福田, 祐仁× 匂坂, 明人× 錦野, 将元× 今園, 孝志× 長谷川, 登× 河内, 哲哉× Daido, Hiroyuki× 加藤, 義章× ブラノフ, セルゲイ× 近藤, 公伯× 神門, 正城× ピロジコフ アレキサンダー× エシロケポフ ティムル× 小倉 浩一× 林 由紀雄× 小瀧 秀行× 桐山 博光× コーガ ジェームズ× 福田 祐仁× 匂坂 明人× 錦野 将元× 今園 孝志× 長谷川 登× 河内 哲哉× 加藤 義章× ブラノフ セルゲイ× 近藤 公伯× 神門 正城 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | *Abstract:* We discuss the new regime of high-order harmonic generation by relativistic-irradiance multi-terawatt femtosecond lasers focused onto gas jet targets [PRL 108, 135004 (2012); NJP 16, 093003 (2014)]. The laser induces multi-stream relativistic plasma flow resulting in the formation of density singularities: structurally stable, oscillating electron spikes coherently emitting high-frequency radiation. In this presentation we analyze the dependence of the harmonic yield on the laser power and focal spot quality, and derive the required laser parameters for efficient harmonics generation. We show the status of the J-KAREN-P laser and report on the progress towards satisfying these requirements. \nIn the new regime of high-order harmonic generation, intense (>10^18 W/cm^2) high-power (multi-TW) femtosecond (30-50 fs) laser pulses focused onto gas targets induce multi-stream relativistic flows in underdense plasma (ne ~ 10^19 cm^-3). This results in the formation of density singularities, which are structurally stable, oscillating electron spikes coherently emitting high-frequency radiation with spectra comprising high-order harmonics [1, 2]. The experiments with the J-KAREN laser [3] demonstrated strong dependence of the harmonics yield on the laser pulse energy and focal spot quality. \nIn this presentation we analyze the obtained dependences and derive laser parameters required for efficient harmonics generation. Apart from higher power, it turns out that the focal spot quality should approach the diffraction limit, i.e. the Strehl ratio should exceed 0.5. The focal spots of high-power lasers typically suffer from wavefront distortions and angular dispersion. For noise-like wavefront distortions, the above stated requirement corresponds to an rms wavefront error <100 nm. The angular dispersion should be kept smaller than a fraction of the diffraction divergence, i.e. urad level for 100 to 300 mm beam diameters. The corresponding angular chirp should be <10^-2 urad/nm for 50 nm bandwidth. We show the status of the J-KAREN-P laser and report on the progress towards satisfying these requirements. \n1.A. S. Pirozhkov, et al., "Soft-X-Ray Harmonic Comb from Relativistic Electron Spikes," Phys. Rev. Lett. 108, 135004-5 (2012). \n2.A. S. Pirozhkov, et al., "High order harmonics from relativistic electron spikes," New J. Phys. 16, 093003-30 (2014). \n3.H. Kiriyama, et al., "High-Contrast, High-Intensity Petawatt-Class Laser and Applications," IEEE J. Sel. Topics Quantum Electron. 21, 1601118-18 (2015). |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The 15th International Conference on X-Ray Lasers (ICXRL2016) | |||||
| 発表年月日 | ||||||
| 日付 | 2016-05-24 | |||||
| 日付タイプ | Issued | |||||
