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Prepulse and amplified spontaneous emission effects on the interaction of a petawatt class laser with thin solid targets

Esirkepov, T. Z.; Koga, J. K.; 砂原 淳*; 守田 利昌; 錦野 将元; 影山 慶*; 長友 英夫*; 西原 功修; 匂坂 明人; 小瀧 秀行; et al.

Nuclear Instruments and Methods in Physics Research A, 745, p.150 - 163, 2014/05

 被引用回数:28 パーセンタイル:2.15(Instruments & Instrumentation)

When a finite contrast petawatt laser pulse irradiates a micron-thick foil, a prepulse creates a preplasma, where an ultrashort relativistically strong portion of the laser pulse acquires higher intensity due to relativistic self-focusing and undergoes fast depletion transferring energy to fast electrons. If the preplasma thickness is optimal, the main pulse can reach the target generating fast ions more efficiently than an ideal, infinite contrast, laser pulse. The optimal conditions for hundreds of MeV ion acceleration are found with accompanying effects important for diagnostics, including high-order harmonics generation.


Controlling the generation of high frequency electromagnetic pulses with relativistic flying mirrors using an inhomogeneous plasma

Lobet, M.*; 神門 正城; Koga, J. K.; Esirkepov, T. Z.; 中村 龍史; Pirozhkov, A. S.; Bulanov, S. V.

Physics Letters A, 377, p.1114 - 1118, 2013/06

 被引用回数:8 パーセンタイル:39.22(Physics, Multidisciplinary)



On extreme field limits in high power laser matter interactions; Radiation dominant regimes in high intensity electromagnetic wave interaction with electrons

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:8 パーセンタイル:1.94

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 $$gamma$$ ray flashes.


On the breaking of a plasma wave in a thermal plasma, 1; The Structure of the density singularity

Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城; Koga, J. K.; Pirozhkov, A. S.; 中村 龍史; Bulanov, S. S.*; Schroeder, C. B.*; Esarey, E.*; Califano, F.*; et al.

Physics of Plasmas, 19(11), p.113102_1 - 113102_14, 2012/11

 被引用回数:11 パーセンタイル:41.72(Physics, Fluids & Plasmas)

The structure of the singularity that is formed in a relativistically large amplitude plasma wave close to the wave breaking limit is found by using a simple waterbag electron distribution function. The electron density distribution in the breaking wave has a typical "peakon" form. The maximum value of the electric field in a thermal breaking plasma is obtained and compared to the cold plasma limit. The results of computer simulations for different initial electron distribution functions are in agreement with the theoretical conclusions.


On the breaking of a plasma wave in a thermal plasma, 2; Electromagnetic wave interaction with the breaking plasma wave

Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城; Koga, J. K.; Pirozhkov, A. S.; 中村 龍史; Bulanov, S. S.*; Schroeder, C. B.*; Esarey, E.*; Califano, F.*; et al.

Physics of Plasmas, 19(11), p.113103_1 - 113103_7, 2012/11

 被引用回数:8 パーセンタイル:53.69(Physics, Fluids & Plasmas)

The structure of the density singularity formed in a relativistically large amplitude plasma wave close to the wave breaking limit leads to a refraction coefficient which has a coordinate dependence with discontinuous derivatives. This results in a non-exponentially small above-barrier reflection of an electromagnetic wave interacting with the nonlinear plasma wave.


X-ray emission from relativistically moving electron density cusps

神門 正城; Pirozhkov, A. S.; 中村 龍史; 林 由紀雄; 小瀧 秀行; 川瀬 啓悟*; Esirkepov, T. Z.; 福田 祐仁; 桐山 博光; 岡田 大; et al.

AIP Conference Proceedings 1465, p.159 - 166, 2012/07


We report on novel method to generate ultra-short coherent X-rays using a laser-plasma interaction. Nonlinear interaction of intense laser pulses with plasma creates stable, specific structures such as electron cusps. For example wake waves excited in an underdense plasma by the laser become dense and propagate along with the laser pulse (Flying Mirror). The flying mirror can reflect a counter-propagating laser pulse and directly convert it into high-frequency radiation and compress the pulse. We have conducted experimental results using 9 TW laser with a He gas target. We observed 10$$^{10}$$ photons in the extreme ultra-violet region (12.8-22.0 nm).


High-power $$gamma$$-ray flash generation in ultraintense laser-plasma interactions

中村 龍史; Koga, J. K.; Esirkepov, T. Z.; 神門 正城; Korn, G.*; Bulanov, S. V.

Physical Review Letters, 108(19), p.195001_1 - 195001_5, 2012/05

 被引用回数:105 パーセンタイル:2.65(Physics, Multidisciplinary)



Laser technologies and the combined applications toward vacuum physics

神門 正城; 中村 龍史; Pirozhkov, A. S.; Esirkepov, T. Z.; Koga, J. K.; Bulanov, S. V.

Progress of Theoretical Physics Supplement, (193), p.236 - 242, 2012/05

Recent progress of the high peak power laser technology allows us to explore the possibility to apply such lasers for fundamental physics. We focus on topics of high energy electron acceleration for colliders, an straw-man proposal to test the Lorentz invariance at ultra-high energy, and a novel technique to enhance focused laser intensity by flying mirrors. We review the experimental results of laser wakefield acceleration (LWFA) and the possibility to apply LWFA for TeV linear colliders. One of the key issues is the lack of driving laser technology to fulfill the requirement in terms of luminosity. If we seek another application taking the advantage of LWFA to reach ultra-high energy, we can propose a test of $$gamma$$-ray's velocity dependence on its energy as expected in some of quantum gravity theories. Finally we give the review of flying mirror schemes, which may boost the laser focused intensity.



中村 龍史

プラズマ・核融合学会誌, 88(1), p.18 - 20, 2012/01



Efficient generation of Xe K-shell X rays by high-contrast interaction with submicrometer clusters

林 由紀雄; Pirozhkov, A. S.; 神門 正城; 福田 祐仁; Faenov, A.*; 川瀬 啓悟*; Pikuz, T.*; 中村 龍史; 桐山 博光; 岡田 大; et al.

Optics Letters, 36(9), p.1614 - 1616, 2011/05

 被引用回数:21 パーセンタイル:21.38(Optics)

3.4MPaのガスノズル圧力のもとで生成させたXeクラスターに25TWレーザーを1$$times$$10$$^{19}$$W/cm$$^2$$の強度で集光照射し、生成する放射線について計測を行った。その結果、この実験条件でXe K殻に由来する約30keVのX線生成をX線CCDで明瞭に観測することに成功した。さらにレーザーエネルギーは一定のままレーザー・パルス幅のXe K殻生成量依存性を調べた。その結果40fsのパルス幅の方が、300fsのパルス幅の時に較べてXe K殻生成量は高くなることが明らかになった。


Ion acceleration in subcritical density plasma via interaction of intense laser pulse with cluster-gas target

福田 祐仁; Faenov, A.*; 反保 元伸; Pikuz, T.*; 中村 龍史; 神門 正城; 林 由紀雄; 余語 覚文; 榊 泰直; 亀島 敬*; et al.

Progress in Ultrafast Intense Laser Science VII, p.225 - 240, 2011/05



FIREX project and effects of self-generated electric and magnetic fields on electron-driven fast ignition

三間 圀興*; 砂原 淳*; 白神 宏之*; 西村 博明*; 疇地 宏*; 中村 龍史; 城崎 知至*; 長友 英夫*; Garcia, C.*; Veralde, P.*

Plasma Physics and Controlled Fusion, 52(12), p.124047_1 - 124047_6, 2010/12

 被引用回数:8 パーセンタイル:60.24(Physics, Fluids & Plasmas)

高速点火核融合は少ないレーザーエネルギーで核融合反応を実現できると期待されている。大阪大学では10kJ, 10psの点火用レーザー(LFEX)を建設中である。現在までに、全4本のビームのうち1本のビームを完成させ統合実験を進めており、幾つか新しい課題が明らかとなってきた。特に、プリパルスによる膨張プラズマの形成により、点火用レーザーのエネルギーが効果的に電子へ変換されていないことが示唆されている。本論文では、プリプラズマの制御を目的としたターゲットのコーティング、また、ダブルコーン形状の採用による電子運動の制御について提案を行った。


Interaction of high contrast laser pulse with foam-attached target

中村 龍史; 反保 元伸; 兒玉 了祐*; Bulanov, S. V.; 神門 正城

Physics of Plasmas, 17(11), p.113107_1 - 113107_6, 2010/11

 被引用回数:32 パーセンタイル:15.2(Physics, Fluids & Plasmas)



High-energy ions from near-critical density plasmas via magnetic vortex acceleration

中村 龍史; Bulanov, S. V.; Esirkepov, T. Z.; 神門 正城

Physical Review Letters, 105(13), p.135002_1 - 135002_4, 2010/09

 被引用回数:77 パーセンタイル:5.88(Physics, Multidisciplinary)



Tomography of an ultrafast laser driven proton source

Ter-Avetisyan, S.*; Schn$"u$rer, M.*; Nickles, P. V.*; Sandner, W.*; Borghesi, M.*; 中村 龍史; 三間 圀興*

Physics of Plasmas, 17(6), p.063101_1 - 063101_6, 2010/06

 被引用回数:5 パーセンタイル:73.66(Physics, Fluids & Plasmas)



Ionization dynamics of cluster targets irradiated by X-ray free-electron-laser light

中村 龍史; 福田 祐仁; 岸本 泰明*

Physical Review A, 80(5), p.053202_1 - 053202_6, 2009/11

 被引用回数:13 パーセンタイル:38.94(Optics)



High energy negative ion generation by Coulomb implosion mechanism

中村 龍史; 福田 祐仁; 余語 覚文; 反保 元伸; 神門 正城; 林 由紀雄; 亀島 敬*; Pirozhkov, A. S.; Esirkepov, T. Z.; Pikuz, T. A.*; et al.

Physics of Plasmas, 16(11), p.113106_1 - 113106_8, 2009/11

 被引用回数:13 パーセンタイル:44.53(Physics, Fluids & Plasmas)



Energy increase in multi-MeV ion acceleration in the interaction of a short pulse laser with a cluster-gas target

福田 祐仁; Faenov, A. Y.; 反保 元伸; Pikuz, T. A.*; 中村 龍史; 神門 正城; 林 由紀雄; 余語 覚文; 榊 泰直; 亀島 敬*; et al.

Physical Review Letters, 103(16), p.165002_1 - 165002_4, 2009/10

 被引用回数:123 パーセンタイル:3(Physics, Multidisciplinary)



Submicron ionography of nanostructures using a femtosecond- laser-driven-cluster-based source

Faenov, A. Y.; Pikuz, T. A.*; 福田 祐仁; 神門 正城; 小瀧 秀行; 本間 隆之; 川瀬 啓悟; 亀島 敬*; Pirozhkov, A. S.; 余語 覚文; et al.

Applied Physics Letters, 95(10), p.101107_1 - 101107_3, 2009/09

 被引用回数:22 パーセンタイル:28.6(Physics, Applied)

An intense isotropic source of multicharged carbon and oxygen ions with energy above 300 keV and high quantity per shot was obtained by femtosecond Ti:Sa laser irradiation of clusters, produced by expansion of the mixed He and CO$$_{2}$$ gases in a supersonic nozzle. The source was employed for high contrast ionography images with 600 nm spatial resolution. A difference in object thickness of 100 nm was well resolved for both Zr and polymer foils.


Coulomb implosion mechanism of negative ion acceleration in laser plasmas

中村 龍史; 福田 祐仁; 余語 覚文; 反保 元伸; 神門 正城; 林 由紀雄; 亀島 敬*; Pirozhkov, A. S.; Esirkepov, T. Z.; Pikuz, T. A.*; et al.

Physics Letters A, 373(30), p.2584 - 2587, 2009/07

 被引用回数:15 パーセンタイル:30.11(Physics, Multidisciplinary)


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