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Oks, E.*; Dalimier, E.*; Faenov, A.*; Pikuz, T.*; 福田 祐仁; Andreev, A.*; Koga, J. K.; 榊 泰直; 小瀧 秀行; Pirozhkov, A. S.; et al.
Optics Express (Internet), 23(25), p.31991 - 32005, 2015/12
被引用回数：7 パーセンタイル：37.60(Optics)フェムト秒高強度レーザーをアルゴンクラスターターゲットに照射して生成したプラズマから発生したアルゴンXVIIスペクトルサテライト線のライン形状を詳細に解析することにより、プラズマ中で非線形現象が起こっていることを明らかにし、その結果、照射レーザー光の第二次高調波(SHG)が発生していることを解明した。サテライト線解析の新しい理論を構築し、入射レーザー光の2 %がSHGに変換されていることを明らかにした。この実験結果は、二次元粒子コードを用いたシミュレーション結果とも良い一致を示した。
Zhidkov, A.*; 益田 伸一*; Bulanov, S. S.*; Koga, J. K.; 細貝 知直*; 兒玉 了祐*
Physical Review Special Topics; Accelerators and Beams, 17(5), p.054001_1 - 054001_7, 2014/05
被引用回数：12 パーセンタイル：61.67(Physics, Nuclear)Nonlinear cascade scattering of intense tightly focused laser pulses by relativistic electrons is studied numerically including the classical radiation damping. The electron energy loss, along with its side scattering by the ponderomotive force makes the scattering in the vicinity of high laser field nearly impossible at high electron energies. The use of a second co-propagating laser pulse as a booster is shown to solve this problem.
Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城; Koga, J. K.; 細貝 知直*; Zhidkov, A.*; 兒玉 了祐*
Physics of Plasmas, 20(8), p.083113_1 - 083113_10, 2013/08
被引用回数：21 パーセンタイル：66.34(Physics, Fluids & Plasmas)Nonlinear axisymmetric cylindrical plasma oscillations in magnetized collisionless plasmas are amodel for the electron fluid collapse at the axis behind the ultrashort relativisically intense laserpulse exciting the plasma wake wave. We present the analytical description of the strongly nonlinear oscillations showing that the magnetic field prevents from closing the cavity formed behind the laserpulse.
Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城; Koga, J. K.; 中村 龍史; Bulanov, S. S.*; Zhidkov, A.*; 加藤 義章; Korn, G.*
High-Power, High-Energy, and High-Intensity Laser Technology; and Research Using Extreme Light: Entering New Frontiers with Petawatt-Class Lasers (Proceedings of SPIE, Vol.8780), p.878015_1 - 878015_15, 2013/05
被引用回数：10 パーセンタイル：96.40(Optics)We discuss the key important regimes of electromagnetic field interaction with charged particles. The main attention is paid to nonlinear Thomson/Compton scattering regime with the radiation friction and quantum electrodynamics effects taking into account. This process opens a channel of high efficiency electromagnetic energy conversion into the hard electromagnetic radiation in the form of ultra short high power 
ray flashes.
Bulanov, S. S.*; Chen, M.*; Schroeder, C. B.*; Esarey, E.*; Leemans, W. P.*; Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城; Koga, J. K.; Zhidkov, A. G.*; et al.
AIP Conference Proceedings 1507, p.825 - 830, 2012/12
被引用回数：9 パーセンタイル：92.52(Physics, Applied)We propose the experiments on the collision of intense laser pulses with energetic electron bunches and on the collision of two or more intense laser pulses for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The regimes of dominant radiation reaction, which completely changes the electromagnetic wave matter interaction, will be revealed in such experiments. This will result in a new powerful source of ultra short high brightness -ray pulses. A possibility of the demonstration of the electron positron pair creation from vacuum in the collision of two or more intense laser pulses is discussed.
水田 好雄*; 細貝 知直*; 益田 伸一*; Zhidkov, A.*; 牧戸 啓悟*; 中新 信彦*; 梶野 祥平*; 西田 明憲*; 神門 正城; 森 道昭; et al.
Physical Review Special Topics; Accelerators and Beams, 15(12), p.121301_1 - 121301_10, 2012/12
被引用回数：21 パーセンタイル：71.50(Physics, Nuclear)Laser wakefield acceleration is capable of generating electron bunches with high quality: quasi-monoenergetic, low in emittance, and a very short duration of the order of ten femto-seconds. Such femtosecond bunches can be used to measure ultrafast phenomena. We conducted experiments for controllable electron bunch generation. Short-lived, 
10 ps, deep plasma channels, with their lengths of 1 mm and diameters of 20 
m, are observed and characterized in Ar gas jets irradiated by moderate intensity, 10
W/cm
, laser pulses with a duration from subpicosecond to several picoseconds. The channels, upon 2D particle-in-cell simulations including ionization, fit well in the guiding of high intensity femtosecond laser pulses and, therefore, in laser wakefield acceleration with a controllable electron self-injection.
Bulanov, S. V.; Esirkepov, T. Z.; 林 由紀雄; 神門 正城; 桐山 博光; Koga, J. K.; 近藤 公伯; 小瀧 秀行; Pirozhkov, A. S.; Bulanov, S. S.*; et al.
AIP Conference Proceedings 1465, p.87 - 96, 2012/07
被引用回数：1 パーセンタイル：45.94(Physics, Applied)In the experiments on the collision of laser light and high intensity electromagnetic pulses generated by relativistic flying mirrors, with electron bunches produced by a conventional accelerator and with laser wake field accelerated electrons the studying of extreme field limits in the nonlinear interaction of electromagnetic waves is proposed. The regimes of dominant radiation reaction, which completely changes the electromagnetic wave-matter interaction, will be revealed. This will result in a new powerful source of high brightness -rays. A possibility of the demonstration of the electron-positron pair creation in vacuum in a multi-photon processes can be realized. This will allow modeling under terrestrial laboratory conditions neutron star magnetospheres, cosmological ray bursts and the Leptonic Era of the Universe.
Zhidkov, A. G.*; Pikuz, S. A.*; Faenov, A. Y.; Chefonov, O. V.*; Ovchinikov, A. V.*; Agranat, M. B.*; Zigler, A.*
Optics Letters, 37(5), p.884 - 886, 2012/03
被引用回数：3 パーセンタイル：17.57(Optics)X ray radiation as high as 50 KeV, including K-shell spectra of Ba, have been observed during the interaction of low energy 0.65 mJ, 1 kHz femtosecond laser pulses focused on the solid target in air of atmospheric pressure. Possible mechanism of such generation by energetic electrons produced when the field strength in laser pulse wake exceeds the runaway threshold in air is considered. Multidimensional particle-in-cell simulations including optical field ionization of air confirm this mechanism.
Bulanov, S. V.; Esirkepov, T. Z.; 林 由紀雄; 神門 正城; 桐山 博光; Koga, J. K.; 近藤 公伯; 小瀧 秀行; Pirozhkov, A. S.; Bulanov, S. S.*; et al.
Nuclear Instruments and Methods in Physics Research A, 660(1), p.31 - 42, 2011/12
被引用回数：72 パーセンタイル：97.99(Instruments & Instrumentation)We propose the experiments on the collision of laser light and high intensity electromagnetic pulses generated by relativistic flying mirrors, with electron bunches produced by a conventional accelerator and with laser wake field accelerated electrons for studying extreme field limits in the nonlinear interaction of electromagnetic waves.
Bulanov, S. V.; Esirkepov, T. Z.; 林 由紀雄; 神門 正城; 桐山 博光; Koga, J. K.; 近藤 公伯; 小瀧 秀行; Pirozhkov, A. S.; Bulanov, S. S.*; et al.
Plasma Physics and Controlled Fusion, 53(12), p.124025_1 - 124025_13, 2011/12
被引用回数：7 パーセンタイル：30.08(Physics, Fluids & Plasmas)We discuss the progress in the development of the extreme light sources that will open new horizons for studying a wide range of the fundamental science and astrophysics problems. The regimes of dominant radiation reaction, which completely change the electromagnetic wave-matter interaction, will be revealed, resulting in a new extremely powerful source of ultra short high brightness -ray pulses. The possibility of abundant electron-positron pair creation via the multi-photon processes, and possibility of reaching the critical field of quantum electrodynamics which would lead to the vacuum polarization and breakdown, are attracting high attention.
Bulanov, S. V.; Esirkepov, T. Z.; 林 由紀雄; 神門 正城; 桐山 博光; Koga, J. K.; 近藤 公伯; 小瀧 秀行; Pirozhkov, A. S.; Bulanov, S. S.*; et al.
Plasma Physics and Controlled Fusion, 53(12), p.124025_1 - 124025_13, 2011/11
The review is devoted to discussing progress in the development of the extreme light sources that opens new horizons for studying of a wide range of the fundamental science problems and important applications.
Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城; Koga, J. K.; Pirozhkov, A. S.; Rosanov, N. N.*; Zhidkov, A.*
AIP Conference Proceedings 1320, p.235 - 243, 2010/12
We formulate the Flying Mirror Concept for relativistic interaction of ultra-intense electromagnetic waves with plasmas, present its theoretical description and the results of computer simulations and laboratory experiments. The reflection of the electromagnetic wave at the relativistic mirror results in its energy and frequency change due to the double Doppler effect. In the co-propagating configuration, in the radiation pressure dominant regime, the energy of the electromagnetic wave is transferred to the ion energy providing a highly efficient acceleration mechanism. In the counter-propagation configuration the frequency of the reflected wave is multiplied by the factor proportional to the -factor squared.
Zhidkov, A.*; Koga, J. K.; 細貝 知直*; 藤井 隆*; 大石 祐嗣*; 根本 孝七*; 兒玉 了祐*
Physics of Plasmas, 17(8), p.083101_1 - 083101_6, 2010/08
被引用回数：11 パーセンタイル：38.92(Physics, Fluids & Plasmas)The wave breaking processes originating from a parametric resonance in the wake of a laser pulse in the absence of pulse over-focusing are thoroughly analyzed via multidimensional particle-in-cell simulations. The processes play a key role in the electron self-injection in the laser-driven acceleration of high energy, mono-energetic electrons in plasma channels. The resonance character of the charge loading in the first, second, and third injections is shown; its effect on the electron acceleration is demonstrated.
Esirkepov, T. Z.; Bulanov, S. V.; 神門 正城; Pirozhkov, A. S.; Zhidkov, A.*
JAEA-Conf 2010-002, p.116 - 119, 2010/06
A novel ultra-bright high-intensity source of X-ray and radiation is proposed. It is based on the double Doppler effect and the radiation pressure dominant regime of ion acceleration. High harmonics generated at the accelerating plasma slab undergo multiplication with the factor equal to the quadruple of the square of the plasma slab Lorentz factor.
Esirkepov, T. Z.; Bulanov, S. V.; Zhidkov, A.*; Pirozhkov, A. S.; 神門 正城
European Physical Journal D, 55(2), p.457 - 463, 2009/11
被引用回数：10 パーセンタイル：43.39(Optics)Employing the "Flying Mirror" concept, we are developing a compact, tunable high-power coherent X-ray source. It will expand the range of applications of the powerful X-ray sources: high-contrast imaging of biological objects, multi-photon ionization in atomic physics and spectroscopy, novel properties of matter in material sciences, and nonlinear quantum electrodynamics processes.
Zhidkov, A.*; Esirkepov, T. Z.; 藤井 隆*; 根本 孝七*; Koga, J. K.; Bulanov, S. V.
Physical Review Letters, 103(21), p.215003_1 - 215003_4, 2009/11
被引用回数：18 パーセンタイル：66.56(Physics, Multidisciplinary)An optically dense ionization wave produced by two femtosecond ( 10/30 fs) laser pulses focused cylindrically and crossing each other may become an efficient coherent X-ray converter in accordance with the Semenova-Lampe theory. The resulting velocity of a quasiplane ionization wave in the vicinity of pulse intersection changes with the angle between the pulses from the group velocity of ionizing pulses to infinity allowing a tuning of the wavelength of X rays and their bunching. The X-ray spectra after scattering of a lower frequency and long coherent light pulse change from the monochromatic to high order harmonic-like with the duration of the ionizing pulses.
Esirkepov, T. Z.; Bulanov, S. V.; 神門 正城; Pirozhkov, A. S.; Zhidkov, A.*
Physical Review Letters, 103(2), p.025002_1 - 025002_4, 2009/07
被引用回数：57 パーセンタイル：87.51(Physics, Multidisciplinary)An ultra-bright high-power X- and -radiation source is proposed. A high-density thin plasma slab, accelerating in the radiation pressure dominant regime by an ultra-intense electromagnetic wave, reflects a counter-propagating relativistically strong electromagnetic wave, producing extremely time-compressed and intensified radiation. The reflected light contains relativistic harmonics generated at the plasma slab, all upshifted with the same factor as the fundamental mode of the incident light. The theory of an arbitrarily moving thin plasma slab reflectivity is presented.
-ray sourceEsirkepov, T. Z.; Bulanov, S. V.; 神門 正城; Pirozhkov, A. S.; Zhidkov, A. G.*
Harnessing Relativistic Plasma Waves as Novel Radiation Sources from Terahertz to X-Rays and Beyond (Proceedings of SPIE Vol.7359), p.735909_1 - 735909_11, 2009/06
被引用回数：1 パーセンタイル：66.09(Optics)An ultra-bright high-power X-ray and -ray source is proposed. A relativistic flying mirror reflects a counter-propagating electromagnetic radiation causing its frequency multiplication and intensification, while the role of the mirror is played by a solid-density thin plasma slab accelerating in the radiation pressure dominant regime. Frequencies of high harmonics generated at the flying mirror by a relativistically strong counter-propagating radiation undergo multiplication with the same factor as the fundamental frequency of the reflected radiation, approximately equal to the quadruple of the square of the mirror Lorentz factor. The theory of the reflectivity of a moving thin plasma slab is presented.
神門 正城; 福田 祐仁; 小瀧 秀行; Koga, J. K.; Bulanov, S. V.; 田島 俊樹; Chao, A. W.*; Pitthan, R.*; Schuler, K.-P.*; Zhidkov, A. G.*; et al.
Journal of Experimental and Theoretical Physics, 105(5), p.916 - 926, 2007/11
被引用回数：15 パーセンタイル：62.51(Physics, Multidisciplinary)高エネルギーのリニアコライダーにも必要とされる低エミッタンスビームを生成する、粒子加速器への新しい入射方法を提案する。本論文では、高出力のレーザーパルスの後に励起される航跡場の加速位相への入射方法を議論する。レーザーの偏光方向と集光方法を変えることにより、横方向の波の破壊を制御して、電子の横方向のベータトロン振動数と振幅を変え、扁平なビームを作り出すことができることを3次元シミュレーションで示した。また、イオンビームでの扁平ビーム生成についても言及する。
大道 博行; 匂坂 明人; 小倉 浩一; 織茂 聡; 西内 満美子; 余語 覚文; 森 道昭; Li, Z.*; 桐山 博光; 金沢 修平; et al.
X-Ray Lasers 2006; Springer Proceedings in Physics, Vol.115, p.595 - 605, 2007/00
現在、関西光科学研究所に設置されている超短パルス高強度レーザーを用いた量子ビーム発生実験を行っている。すなわちレーザーを厚さ数ミクロンの薄膜に照射することにより、プロトン,X線,テラヘルツ波,電子線が発生する。これらは時間同期がきちんととれており、時間幅も1ピコ秒以下であり、するどい指向性を有し輝度も高い。これらを組合せることにより、極めて新しいポンプ-プローブ計測等が可能になると考えられる。これら研究の現状と今後の方向について報告する。
