Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
CoSiYamauchi, Hiroki; Sari, D. P.*; Yasui, Yukio*; Sakakura, Terutoshi*; Kimura, Hiroyuki*; Nakao, Akiko*; Ohara, Takashi; Honda, Takashi*; Kodama, Katsuaki; Igawa, Naoki; et al.
Physical Review Research (Internet), 6(1), p.013144_1 - 013144_9, 2024/02
Yogo, Akifumi*; Lan, Z.*; Arikawa, Yasunobu*; Abe, Yuki*; Mirfayzi, S. R.*; Wei, T.*; Mori, Takato*; Golovin, D.*; Hayakawa, Takehito*; Iwata, Natsumi*; et al.
Physical Review X, 13(1), p.011011_1 - 011011_12, 2023/01
Times Cited Count：3 Percentile：88.42(Physics, Multidisciplinary)
iron-based superconductor LaFePO
Ishikado, Motoyuki*; Shamoto, Shinichi; Kodama, Katsuaki; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Hong, T.*; Mutka, H.*
Scientific Reports (Internet), 8, p.16343_1 - 16343_6, 2018/11
Times Cited Count：3 Percentile：29.25(Multidisciplinary Sciences)Spin fluctuations are widely believed to play an important role as one of the most possible mechanisms for unconventional high-temperature superconductors. Here, the spin fluctuation in LaFePO is found at high energies such as 30-50 meV with comparable intensity to an optimally doped LaFeAs(O,F).
Oks, E.*; Dalimier, E.*; Faenov, A.*; Pikuz, T.*; Fukuda, Yuji; Andreev, A.*; Koga, J. K.; Sakaki, Hironao; Kotaki, Hideyuki; Pirozhkov, A. S.; et al.
Optics Express (Internet), 23(25), p.31991 - 32005, 2015/12
Times Cited Count：7 Percentile：38.91(Optics)We present experiments dealing with a femtosecond laser-driven cluster-based plasma, where by analyzing the nonlinear phenomenon of satellites of spectral lines of Ar XVII, we revealed the nonlinear phenomenon of the generation of the second harmonic of the laser frequency. For performing this analysis we developed new results in the theory of satellites of spectral lines. From such lineshape analysis we found, in particular, that the efficiency of converting the short (40 fs) intense (3
10
W/cm
) incident laser light into the second harmonic was 2%. This result is in the excellent agreement with the 2-Dimensional Particle-In-Cell (2D PIC) simulation that we also performed. There is also an order of magnitude agreement between the thresholds for the SHG found from the line shape analysis and from the 2D PIC simulations.
Pikuz, T.*; Faenov, A.*; Matsuoka, Takeshi*; Matsuyama, Satoshi*; Yamauchi, Kazuto*; Ozaki, Narimasa*; Albertazzi, B.*; Inubushi, Yuichi*; Yabashi, Makina*; Tono, Kensuke*; et al.
Scientific Reports (Internet), 5, p.17713_1 - 17713_10, 2015/12
Times Cited Count：38 Percentile：87.97(Multidisciplinary Sciences)Faenov, A.*; Matsubayashi, Masahito; Pikuz, T.*; Fukuda, Yuji; Kando, Masaki; Yasuda, Ryo; Iikura, Hiroshi; Nojima, Takehiro; Sakai, Takuro; Shiozawa, Masahiro*; et al.
High Power Laser Science and Engineering, 3, p.e27_1 - e27_9, 2015/10
Times Cited Count：10 Percentile：49.69(Optics)Bulanov, S. V.; Esirkepov, T. Z.; Kando, Masaki; Koga, J. K.; Hosokai, Tomonao*; Zhidkov, A.*; Kodama, Ryosuke*
Physics of Plasmas, 20(8), p.083113_1 - 083113_10, 2013/08
Times Cited Count：19 Percentile：64.31(Physics, Fluids & Plasmas)Fukuda, Yuji; Faenov, A.*; Tampo, Motonobu; Pikuz, T.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kameshima, Takashi*; et al.
Progress in Ultrafast Intense Laser Science VII, p.225 - 240, 2011/05
http://www.springer.com/physics/atomic,+molecular,+optical+%26+plasma+physics/book/978-3-642-18326-3We present substantial enhancement of the accelerated ion energies up to 10-20 MeV per nucleon by utilizing the unique properties of the cluster-gas target irradiated with 40-fs laser pulses of only 150 mJ energy, corresponding to approximately tenfold increase in the ion energies compared to previous experiments using thin foil targets. A particle-in-cell simulation infers that the high energy ions are generated at the rear side of the target due to the formation of a strong dipole vortex structure in sub-critical density plasmas. The demonstrated method can be important in the development of efficient laser ion accelerators for hadron therapy and other applications.
Fukuda, Yuji; Faenov, A. Y.; Tampo, Motonobu; Pikuz, T. A.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kameshima, Takashi*; et al.
Physical Review Letters, 103(16), p.165002_1 - 165002_4, 2009/10
Times Cited Count：162 Percentile：96.67(Physics, Multidisciplinary)A new approach for accelerating ions, based on the use of a cluster-gas target and a compact ultrashort pulse laser, is presented. It is shown that ions with energy 10-20 MeV per nucleon having a small divergence (full angle) of 3.4
are generated, corresponding to an approximately tenfold increase in the ion energies compared to previous experiments using solid targets. It is inferred from a particle-in-cell code simulation that the high energy ions are generated at the rear side of the target due to the formation of a strong dipole vortex structure in near-critical density plasmas.
Fukuda, Yuji; Faenov, A. Y.; Tampo, Motonobu; Pikuz, T. A.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kameshima, Takashi; et al.
AIP Conference Proceedings 1153, p.85 - 93, 2009/07
When the target consists of solid-density clusters embedded in the background gas, its irradiation by high intensity laser light renders ion acceleration a truly unique property. We present that the cluster-gas target, which consists of submicron-sized clusters and background gases, irradiated by a few TW laser pulse produces high energy ions upward of the order of 10-20 MeV/n in the forward direction.
Lei, A. L.*; Cao, L. H.*; Yang, X. Q.*; Tanaka, Kazuo*; Kodama, Ryosuke*; He, X. T.*; Mima, Kunioki*; Nakamura, Tatsufumi; Norimatsu, Takayoshi*; Yu, W.*; et al.
Physics of Plasmas, 16(2), p.020702_1 - 020702_4, 2009/02
Times Cited Count：12 Percentile：42.72(Physics, Fluids & Plasmas)The fast electron propagation in an inverse cone target is investigated computationally and experimentally. Two-dimensional particle-in-cell simulation shows that fast electrons with substantial numbers are generated at the outer tip of an inverse cone target irradiated by a short intense laser pulse. These electrons are guided and confined to propagate along the inverse cone wall, forming a large surface current. The experiment qualitatively verifies the guiding and confinement of the strong electron current in the wall surface. The large surface current and induced strong field s are of importance for fast ignition related research.
Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.
Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03
no abstracts in English
SbTe
revealed by the atomic pair distribution function analysisShamoto, Shinichi; Kodama, Katsuaki; Iikubo, Satoshi; Taguchi, Tomitsugu; Yamada, Noboru*; Proffen, T.*
Japanese Journal of Applied Physics, Part 1, 45(11), p.8789 - 8794, 2006/11
Times Cited Count：17 Percentile：53.14(Physics, Applied)Two types of optical recording crystalline material GeSbTe have been studied by neutron and X-ray powder diffraction measurements. One is the crystalline cubic-phase GeSbTe. The other is nanocrystalline-phase GeSbTe. For the nanocrystalline phase, the local crystal structure and the particle size distribution were obtained simultaneously by PDF analysis using a spherical-particle form factor. The lattice parameter is longer than that of the crystalline phase, suggesting an antimony-richer composition than the matrix. This compositional deviation would form the nanoparticle, resulting in nucleation-dominated crystal growth.
Onozuka, Masanori*; Ioki, Kimihiro*; Johnson, G.*; Kodama, T.*; Sonnazzaro, G.*; Utin, Y.*
Fusion Engineering and Design, 51-52(Part.B), p.249 - 255, 2000/11
Times Cited Count：5 Percentile：37.66(Nuclear Science & Technology)no abstracts in English
*; Ioki, Kimihiro*; F.Elio*; Kodama, T.*; S.Chiocchio*; D.Williamson*; M.Roccella*; P.Barabaschi*; R.S.Sayer*
Fusion Technology 1998, 2, p.1389 - 1392, 1998/00
no abstracts in English
and GeSbTe nanoparticlesShamoto, Shinichi; Kodama, Katsuaki; Iikubo, Satoshi; Taguchi, Tomitsugu; Proffen, T.*; Yamada, Noboru*
no journal, ,
A nanoparticle has large surface area in the ratio, which would have different crystal structure from the inside. As for a catalyst, the surface plays an important role in the functionality. Structural analysis of the whole particle is an important step toward understanding the property. Recent high intensity quantum beams, such as pulsed neutron and synchrotron X-ray provide us a possibility for the analysis, which needs high Q-resolution and high intensity simultaneously. TiO and GeSbTe nanoparticles are photocatalyst and optical recording materials, respectively. The former particles are isolated individually, while the latter particles are embedded in an amorphous matrix. These two typical nanoparticles have been studied by the atomic pair distribution function (PDF) analysis with the spherical particle form factor using neutron powder diffraction data obtained at NPDF in LANSCE.
Shamoto, Shinichi; Kodama, Katsuaki; Iikubo, Satoshi; Taguchi, Tomitsugu; Proffen, T.*; Yamada, Noboru*
no journal, ,
It will be possible to study novel nanomaterials by high intensity, high Q-resolution, and wide Q-range pulsed neutron scattering at intense pulsed neutron sources. The atomic pair distribution function analysis for the crystalline nanomaterials, however, has not been developed so far. We will discuss the characteristic finite size effects on the PDF analysis.
SbTe revealed by the atomic pair distribution function analysisShamoto, Shinichi; Kodama, Katsuaki; Iikubo, Satoshi; Taguchi, Tomitsugu; Yamada, Noboru*; Proffen, T.*
no journal, ,
no abstracts in English
Shamoto, Shinichi; Iikubo, Satoshi; Kodama, Katsuaki; Taguchi, Tomitsugu; Proffen, T.*
no journal, ,
Wide r-range atomic pair distribution function (PDF) over 200 
is becoming available at a high Q-resolution and high intensity total scattering diffractometer in a recent intense pulsed neutron source facility. By using the PDF, whole nanoparticle crystal structure could be studied in principle. Toward the goal, we have studied nanoparticle form factor effects on PDF. Our recent results obtained at NPDF in LANSCE will be reported.
Shamoto, Shinichi; Iikubo, Satoshi; Kodama, Katsuaki; Taguchi, Tomitsugu; Koyanaka, Hideki*; Takeuchi, Ken*; Kohara, Shinji*; Loong, C.-K.*; Proffen, T.*
no journal, ,
Local crystal structures of nano-transition-metal-oxide powder samples, such as manganese oxide and titanium oxide, have been studied by the atomic pair distribution function (PDF) analysis of X-ray and neutron powder diffraction data. For example, the nano-manganese-oxide (nano-Mn-O) sample with unknown crystal structure shows ultrahigh efficiency as a gold adsorbent even from ppt-level aqueous solutions such as the seawater. For the nanomaterials, there are various difficulties to determine the crystallographic parameters. Instead of fitting broad diffraction peaks, the PDF reveals relatively sharp features at short interatomic distances. For example, by analyzing the peak areas in absolute scale, a valence of a manganese ion or an atomic fraction of manganese ion in the nano-Mn-O sample, MnO
, can be determined.