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Li, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count:1 Percentile:42.63(Chemistry, Analytical)no abstracts in English
Yoshida, Koji*; Sanada, Yusuke*; Yamaguchi, Toshio*; Matsuura, Masato*; Tamatsukuri, Hiromu; Uchiyama, Hiroshi*
Journal of Molecular Liquids, 366, p.120218_1 - 120218_9, 2022/11
Times Cited Count:0 Percentile:24.72(Chemistry, Physical)Nakano, Masahiro*; Yamaguchi, Yuji; Uozumi, Yusuke*
Physical Review C, 106(1), p.014612_1 - 014612_8, 2022/07
Times Cited Count:0 Percentile:0.02(Physics, Nuclear)Deuteron-induced nonelastic cross sections are studied in an extended intranuclear cascade (INC) model. A three-body framework of proton, neutron, and target is introduced into the INC model to incorporate naturally the decomposition and capture reactions from weakly bound deuterons. This framework includes three types of interaction potential, namely proton-target, neutron-target, and proton-neutron, the last of which causes the two nucleons in the deuteron to oscillate and play an important role in its breakup. The calculated results reproduce well the experimental data for C,
Ca,
Ni, and
Pb targets with almost the same parameters as those determined previously for nucleon-induced nonelastic reactions.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count:30 Percentile:96.42(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200
C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.
Science, 364(6437), p.272 - 275, 2019/04
Times Cited Count:233 Percentile:99.75(Multidisciplinary Sciences)The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Matsuoka, Moe*; Nakamura, Tomoki*; Osawa, Takahito; Iwata, Takahiro*; Kitazato, Kohei*; Abe, Masanao*; Nakauchi, Yusuke*; Arai, Takehiko*; Komatsu, Mutsumi*; Hiroi, Takahiro*; et al.
Earth, Planets and Space (Internet), 69(1), p.120_1 - 120_12, 2017/09
Times Cited Count:5 Percentile:22.94(Geosciences, Multidisciplinary)We have conducted ground-based performance evaluation tests of the Near-Infrared Spectrometer (NIRS3) onboard Hayabusa2 spacecraft and established a method for evaluating its measured reflectance spectra. Reflectance spectra of nine powdered carbonaceous chondrite samples were measured by both NIRS3 and a FT-IR spectrometer. Since raw data obtained by NIRS3 had considerable spectral distortion caused by systematic offsets in sensitivity of individual pixels, we have established two methods for correcting the NIRS3 data by comparing them with the corresponding FT-IR data. In order to characterize the absorption bands in NIRS3 spectra, the depth of each band component D is defined for each wavelength
(
m). Reflectance spectra of asteroid Ryugu, the target asteroid of Hayabusa2, to be recorded by the NIRS3 are expected to reveal the characteristics of the surface materials by using the evaluation technique.
Masuda, Toshiyuki*; Arase, Junko*; Inagaki, Yusuke*; Kawahara, Masatoshi*; Yamaguchi, Kentaro*; Ohara, Takashi; Nakao, Akiko*; Momma, Hiroyuki*; Kwon, E.*; Setaka, Wataru*
Crystal Growth & Design, 16(8), p.4392 - 4401, 2016/08
Times Cited Count:27 Percentile:88.4(Chemistry, Multidisciplinary)Ito, Shinichi*; Yokoo, Tetsuya*; Masuda, Takatsugu*; Yoshizawa, Hideki*; Soda, Minoru*; Ikeda, Yoichi*; Ibuka, Soshi*; Kawana, Daichi*; Sato, Taku*; Nambu, Yusuke*; et al.
JPS Conference Proceedings (Internet), 8, p.034001_1 - 034001_6, 2015/09
Minami, Ryutaro*; Kariya, Tsuyoshi*; Imai, Tsuyoshi*; Numakura, Tomoharu*; Endo, Yoichi*; Nakabayashi, Hidetaka*; Eguchi, Taku*; Shimozuma, Takashi*; Kubo, Shin*; Yoshimura, Yasuo*; et al.
Nuclear Fusion, 53(6), p.063003_1 - 063003_7, 2013/06
Minami, Ryutaro*; Kariya, Tsuyoshi*; Imai, Tsuyoshi*; Numakura, Tomoharu*; Endo, Yoichi*; Nakabayashi, Hidetaka*; Eguchi, Taku*; Shimozuma, Takashi*; Kubo, Shin*; Yoshimura, Yasuo*; et al.
Nuclear Fusion, 53(6), p.063003_1 - 063003_7, 2013/06
Times Cited Count:12 Percentile:48.21(Physics, Fluids & Plasmas)Nagaoka, Shinichi*; Fukuzawa, Hironobu*; Prmper, G.*; Takemoto, Mai*; Takahashi, Osamu*; Yamaguchi, Takuhiro*; Kakiuchi, Takuhiro*; Tabayashi, Kiyohiko*; Suzuki, Isao*; Harries, J.; et al.
Journal of Physical Chemistry A, 115(32), p.8822 - 8831, 2011/07
Times Cited Count:28 Percentile:71.6(Chemistry, Physical)Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count:176 Percentile:99.42(Physics, Nuclear)Transverse momentum distributions and yields for , and
in
collisions at
= 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different
collisions. We also present the scaling properties such as
and
scaling and discuss the mechanism of the particle production in
collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count:7 Percentile:46.42(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to
collisions.
Sato, Shoichi*; Ichimura, Makoto*; Yamaguchi, Yusuke*; Katano, Makoto*; Imai, Yasutaka*; Murakami, Tatsuya*; Miyake, Yuichiro*; Yokoyama, Takuro*; Moriyama, Shinichi; Kobayashi, Takayuki; et al.
Plasma and Fusion Research (Internet), 5, p.S2067_1 - S2067_4, 2010/12
Ion cyclotron emissions (ICEs) due to deuterium-deuterium fusion-product (FP) ions on JT-60U are studied. ICE due to H-ions is identified from the difference of the toroidal wave number of 2nd ICE(D). The parameter dependence for the appearance of ICE(H) is investigated from the experimental conditions and also is studied by using "Escape Particle Orbit analysis Code (EPOC)".
Ichimura, Makoto*; Higaki, Hiroyuki*; Kakimoto, Shingo*; Yamaguchi, Yusuke*; Nemoto, Tatsuki*; Katano, Makoto*; Ishikawa, Masao; Moriyama, Shinichi; Suzuki, Takahiro
Nuclear Fusion, 48(3), p.035012_1 - 035012_7, 2008/03
Times Cited Count:40 Percentile:82.56(Physics, Fluids & Plasmas)In this paper, experimental observations of spontaneously excited waves in the ion cyclotron range of frequency (ICRF) on JT-60U are described. The fluctuations in ICRF are driven by the presence of non-thermal ion distribution in magnetic confinement plasmas. Two types of magnetic fluctuations are detected: one is due to high energy D ions from neutral beam injections and the other is due to fusion products (FPs) of He and T ions. These fluctuations have been reported as ion cyclotron emissions (ICEs) in the burning plasma experiments on large tokamaks. This paper describes the first measurement of the spatial structures of the excited modes in the poloidal and toroidal directions. It is confirmed by using ICRF antennas as magnetic probes that all modes excited spontaneously have magnetic components and couple to the antenna straps. The modes due to D ions have small toroidal wave number
and will behave as electrostatic waves. On the while, the measurement of finite
in the modes due to FP ions supports the excitation of the Alfv
n waves is the possible origin of FP-ICEs. It is also confirmed that the excited modes due to FP ions have different wave structures and are suggested to be in the different branch of the Alfv
n waves, that is, the fast Alfv
n wave and the slow Alfv
n wave. Frequency peaks due to FP ions are sometimes split into doublet shape as observed in JET experiments. The phase differences of both peaks are measured and indicate that two waves are traveling in both toroidal directions. Both beam-driven ICEs and FP-ICEs are observed and those spatial structures are obtained on JT-60U.
Ichimura, Makoto*; Higaki, Hiroyuki*; Kakimoto, Shingo*; Yamaguchi, Yusuke*; Nemoto, Kenju*; Katano, Makoto*; Kozawa, Isao*; Muro, Taishi*; Ishikawa, Masao; Moriyama, Shinichi; et al.
Fusion Science and Technology, 51(2T), p.150 - 153, 2007/02
Times Cited Count:1 Percentile:11.4(Nuclear Science & Technology)In magnetically confined plasmas, fluctuations in the ion cyclotron range of frequency (ICRF) will be driven by the presence of non-thermal ion energy distribution. In strong ICRF heating experiments on the GAMMA 10 tandem mirror, plasmas with a strong temperature anisotropy have been formed. Alfven-ion-cyclotron (AIC) modes are spontaneously excited due to strong temperature anisotropy. High-energy ions are trapped in the local mirror and will form the velocity distribution with the strong anisotropy. To study the relation among the AIC modes, ICEs and beam-driven electrostatic instabilities with non-thermal energy distribution is the main purpose of this work. When the NBs are injected, the magnetic fluctuations due to injected beams and FP ions are detected by ICRF antennas used as pickup loops on JT-60U. The wave excitation near ion cyclotron and its higer harmonic frequencies are studied experimentally and theoretically in plasmas with non-thermal ion energy distribution.
Ichimura, Makoto*; Yamaguchi, Yusuke*; Nemoto, Kenju*; Katano, Makoto*; GAMMA10 Group*; Ishikawa, Masao*; Moriyama, Shinichi; Suzuki, Takahiro
no journal, ,
The measurement of fusion product (FP) ICEs will become a significant diagnostic tool for fusion reactions. The precise study of the excitation mechanism is important for future burning plasma experiments. In strong ICRF heating experiments on the GAMMA 10 tandem mirror, plasmas with a strong temperature anisotropy have been formed when the resonance layer exists near the mid-plane of the central cell. In a typical discharge, Alfven-ion-cyclotron (AIC) modes are spontaneously excited due to such a strong temperature anisotropy. On the while, the injection of low power ICRF waves into the plasma as active diagnostics has been tested in GAMMA 10. A wide band ICRF probe system was constructed. In the present experimental conditions, the inhomogeneity scale length of the plasma and the magnetic field configuration is in the same order of the wavelength. Wave excitation is strongly affected by the boundary conditions. The waves excited in the plasma are detected with a magnetic probe. In the presentation, the experimental results of the ICRF probe system in GAMMA 10 for active diagnostics and the observation of ICEs in JT-60U for passive diagnostics are reported.
Ichimura, Makoto*; Higaki, Hiroyuki*; Yamaguchi, Yusuke*; Nemoto, Tatsuki*; Katano, Makoto*; Motegi, Yukimi*; Kozawa, Isao*; Muro, Taishi*; Ishikawa, Masao; Moriyama, Shinichi; et al.
no journal, ,
The wave excitation in the ion cyclotron range of frequency (ICRF) is strongly affected by the boundary conditions. The formation of eigenmodes depends on the plasma parameters, their spatial profiles, the magnetic field profile and so on. The main subject of this presentation is the establishment of plasma diagnostics with ICRF waves. In GAMMA 10, the injection of low power ICRF waves into the plasma as active diagnostics has been tested. The preliminary results are reported. In JT-60U, the ion cyclotron emissions (ICEs) due to high energy ions from the neutral beam injections and the fusion reactions have been clearly observed. The frequency spectra of ICEs also depend on the plasma parameters. ICEs for passive diagnostic tools are discussed.
Katano, Makoto*; Ichimura, Makoto*; Yamaguchi, Yusuke*; Motegi, Yukimi*; Muro, Taishi*; Ouchi, Toshiaki*; Oishi, Junya*; Sato, Shoichi*; Ishikawa, Masao; Moriyama, Shinichi; et al.
no journal, ,
The understanding of spontaneously excited waves in plasmas with anisotropic velocity distributions is the main purpose of this presentation. In JT-60U, the ion cyclotron emissions (ICEs) due to fusion product ions have been experimentally observed. By using the local dispersion relation in hot plasmas, the excitation of slow and fast Alfvn waves are evaluated. The excitation mechanism for ICEs due to fusion product ions are discussed.
Ichimura, Makoto*; Yamaguchi, Yusuke*; Sato, Shoichi*; Katano, Makoto*; Ouchi, Toshiaki*; Muro, Taishi*; Sekihara, Yusuke*; Murakami, Tatsuya*; Moriyama, Shinichi; Kobayashi, Takayuki; et al.
no journal, ,
Fluctuations in the ion cyclotron range of frequency are investigated both on GAMMA 10 and JT-60U. Ion cyclotron emissions (ICEs) due to deuterium-deuterium fusion-product (FP) ions on JT-60U are described. ICE due to H-ions is newly identified. ICE(T) with lower frequency has larger wave numbers than ICE (He) in the same discharge. The excitation of slow Alfv
n waves is elucidated for the first time as the mechanism for ICE due to T-ions. The anisotropy of T-ions at the outer plasma edge is evaluated by using Escape Particle Orbit analysis Code (EPOC).