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LiIshiyama, Hironobu*; Jeong, S.-C.*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Jung, H. S.*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Osa, Akihiko; Otokawa, Yoshinori; et al.
Nuclear Instruments and Methods in Physics Research B, 376, p.379 - 381, 2016/06
Times Cited Count：8 Percentile：60.26(Instruments & Instrumentation)Li tracerIshiyama, Hironobu*; Jeong, S.-C.*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Katayama, Ichiro*; Osa, Akihiko; Otokawa, Yoshinori; et al.
Japanese Journal of Applied Physics, 53(11), p.110303_1 - 110303_4, 2014/11
Times Cited Count：4 Percentile：18.17(Physics, Applied)Hirayama, Yoshikazu*; Mihara, Mototsugu*; Watanabe, Yutaka*; Jeong, S. C.*; Miyatake, Hiroari*; Momota, Sadao*; Hashimoto, Takashi*; Imai, Nobuaki*; Matsuta, Kensaku*; Ishiyama, Hironobu*; et al.
European Physical Journal A, 48(5), p.54_1 - 54_10, 2012/05
Times Cited Count：2 Percentile：16.82(Physics, Nuclear)
collisions at 
= 200 and 62.4 GeVAdare, 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：184 Percentile：99.44(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.
and Au+Au collisions at 
= 200 GeVAdare, 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：8 Percentile：49.7(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.
Imai, Yoshinori*; Takahashi, Hideyuki*; Kitagawa, Kentaro*; Matsubayashi, Kazuyuki*; Nakai, Noriyuki*; Nagai, Yuki; Uwatoko, Yoshiya*; Machida, Masahiko; Maeda, Atsutaka*
Journal of the Physical Society of Japan, 80(1), p.013704_1 - 013704_4, 2011/01
Times Cited Count：36 Percentile：81.82(Physics, Multidisciplinary)no abstracts in English
Imai, Nobuaki*; Jeong, S.-C.*; Oyaizu, Mitsuhiro*; Arai, Shigeaki*; Fuchi, Yoshihide*; Hirayama, Yoshikazu*; Ishiyama, Hironobu*; Miyatake, Hiroari; Tanaka, Masahiko*; Okada, Masayuki*; et al.
Review of Scientific Instruments, 79(2), p.02A906_1 - 02A906_3, 2008/02
Times Cited Count：13 Percentile：51.72(Instruments & Instrumentation)KEKCB is an 18 GHz Electron Cyclotron Resonance (ECR) ion source and is a charge breeder device for converting mass-separated 1
radioactive ions to multi-ionized ones by utilizing an axial injection technique to the ECR plasma. It is a part of the Tokai Radioactive Ion Accelerator Complex (TRIAC) facility. Based on the developments so far, converting efficiencies for metal elements, such as barium and indium, and for gaseous elements, such as krypton and xenon, are improved to be 7 
and 2 , respectively. And it is confirmed that the efficiency is nearly the constant for short-lived (t
1 sec) isotopes. Background ions mixed in the output beams are supressed to be 600 pps from 10
pps by applying all aluminum electrodes and high pressure pure-water cleanings.
Imai, Tsuyoshi*; Tatematsu, Yoshinori*; Numakura, Tomoharu*; Sakamoto, Keishi; Minami, Ryutaro*; Watanabe, Osamu*; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Kamata, Yasuhiro*; Machida, Norihito*; et al.
Fusion Science and Technology, 51(2T), p.208 - 212, 2007/02
Times Cited Count：9 Percentile：54.87(Nuclear Science & Technology)no abstracts in English
Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Imai, Tsuyoshi*; Saito, Teruo*; Tatematsu, Yoshinori*; Sakamoto, Keishi; Minami, Ryutaro*; Watanabe, Osamu*; Numakura, Tomoharu*; Endo, Yoichi*
Fusion Science and Technology, 51(2T), p.397 - 399, 2007/02
Times Cited Count：11 Percentile：61.1(Nuclear Science & Technology)no abstracts in English
Kamata, Yasuhiro*; Imai, Tsuyoshi*; Tatematsu, Yoshinori*; Watanabe, Osamu*; Minami, Ryutaro*; Saito, Teruo*; Sakamoto, Keishi; Kariya, Tsuyoshi*; Mitsunaka, Yoshika*; Machida, Norihito*; et al.
Fusion Science and Technology, 51(2T), p.412 - 414, 2007/02
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
superconductivity"Arai, Masatoshi; Yokoo, Tetsuya*; Kajimoto, Ryoichi; Nakajima, Kenji; Shamoto, Shinichi; Yamada, Kazuyoshi*; Fujita, Masaki*; Ino, Takashi*; Soyama, Kazuhiko; Nakamura, Mitsutaka; et al.
JAEA-Review 2006-033, 58 Pages, 2006/11
JAEA-Review-2006-033.pdf:17.22MB
A research project entitled "Development of the 4D Space Access Neutron Spectrometer (4SEASONS) and Elucidation of the Mechanism of Oxide High- Superconductivity" has started in 2005 (repr. by M. Arai). It is supported by MEXT, Grant-in-Aid for Specially Promoted Research and is going to last until fiscal 2009. The goal of the project is to elucidate the mechanism of oxide high- superconductivity by neutron scattering technique. For this purpose, we will develop an inelastic neutron scattering instrument 4SEASONS (4d SpacE AccesS neutrON Spectrometer) for the spallation neutron source in Japan Proton Accelerator Research Complex (J-PARC). The instrument will have 100 times higher performance than existing world-class instruments, and will enable detailed observation of anomalous magnetic excitations and phonons in a four-dimensional momentum-energy space. This report summarizes the progress in the research project in fiscal 2007.
Saigusa, Mikio*; Takahashi, Koji; Kashiwa, Yoshinori*; Oishi, Shimpei*; Hoshi, Yuki*; Nakahata, Hiroyuki*; Kasugai, Atsushi; Sakamoto, Keishi; Imai, Tsuyoshi*
Fusion Engineering and Design, 74(1-4), p.473 - 478, 2005/11
Times Cited Count：4 Percentile：30.51(Nuclear Science & Technology)The specification of an electron cyclotron current driving (ECCD) system in International Thermonuclear Experimental Reactor (ITER) demands severe operational conditions for transmission lines and polarizers. For evaluating Ohmic loss of a miter bend type polarizer, the six polarizers were made of chromium copper alloy, installed in miter bends and tested at a frequency of 170GHz, rf power of 441kW and pulse duration of 0.1-6 seconds. The increase in temperature on the back of the grooved mirrors has been measured with thermo couplers during high power rf pulses. The Ohmic loss of grooved mirrors strongly depends on the rotation angle of the polarization plane of the incident waves and the mirror rotation in high power experiments, for example the Ohmic loss distributed from 0.2% to1.6%. The thermal analysis of grooved mirror has been performed with the 3D FEM code: FEVA. The all strange behavior of Ohmic loss of polarizers could be explained, theoretically.
Kashiwa, Yoshinori*; Saigusa, Mikio*; Takahashi, Koji; Oishi, Shimpei*; Hoshi, Yuki*; Kasugai, Atsushi; Sakamoto, Keishi; Imai, Tsuyoshi
Proceedings of 2004 International Symposium on Microwave Science and Its Application to Related Fields (Microwave 2004), p.527 - 530, 2004/07
An electron cyclotron current drive (ECCD) system is, especially, necessary to suppress the neoclassical tearing mode instability in ITER. The polarizers are one of the important components in the ECCD system, to generate optimum polarization for an efficient ECCD. An ohmic loss of the polarizers is evaluated, when 170GHz, high power RF wave taransmits, in oreder to investigate its performance. The maximum temperature increase on the back plate of the deep grooved and the conventinal type were 65
C and 30C, respectively. RF power and pulse were 441kW and 6sec, respectively. The dependence of temperature increase on the plolarizer angle obtained in the experiment agrees with the calculation, qualitatively. It was also found that the significant reduction of ohmic loss on the polarizers was achievable with the optimized rotation angle of the linearly polarized incident wave.
Kamada, Yutaka; Fujita, Takaaki; Ishida, Shinichi; Kikuchi, Mitsuru; Ide, Shunsuke; Takizuka, Tomonori; Shirai, Hiroshi; Koide, Yoshihiko; Fukuda, Takeshi; Hosogane, Nobuyuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.185 - 254, 2002/09
Times Cited Count：34 Percentile：48.48(Nuclear Science & Technology)With the main aim of providing physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has been developing and optimizing the operational concepts, and extending the discharge regimes toward sustainment of high integrated performance in the reactor relevant parameter regime. In addition to achievement of the equivalent break-even condition (QDTeq up to 1.25) and a high fusion triple product = 1.5E21 m-3skeV, JT-60U has demonstrated the integrated performance of high confinement, high beta-N, full non-inductive current drive with a large fraction of bootstrap current in the reversed magnetic shear and in the high-beta-p ELMy H mode plasmas characterized by both internal and edge transport barriers. The key factors in optimizing these plasmas are profile and shape controls. As represented by discovery of various Internal Transport Barriers, JT-60/JT-60U has been emphasizing freedom and restriction of profiles in various confinement modes. JT-60U has demonstrated applicability of these high confinement modes to ITER and also clarified remaining issues.
Eto, Tetsujiro*; Endo, Shoichi*; Imai, Motoharu*; Katayama, Yoshinori; Kikegawa, Takumi*
Physical Review B, 61(22), p.14984 - 14988, 2000/06
Times Cited Count：51 Percentile：87.97(Materials Science, Multidisciplinary)The pressure effect on the lattice constant of NiO with the rhombohedral distorted B1 structure was studied up to 141 GPa by 
angle-dispersive x-ray diffraction using synchrotron radiation, an imaging plate, and a diamond anvil cell. The lattice constant 
and 
, expressed in the hexagonal lattice, decrease monotonously with increasing pressure. The axial rage 
decreases monotonously with increasing pressure, indicating the distortion in the rhombohedral [111] direction becomes larger as pressure increases. The signiifcant change of above 60 GPa, suggested by a recent theoretical calculation, was not observed.
Eto, Tetsujiro*; Endo, Shoichi*; Imai, Motoharu*; Katayama, Yoshinori; Kikegawa, Takumi*
Science and Technology of High Pressure (Proceedings of AIRAPT-17), p.487 - 490, 2000/00
The pressure effect on the lattice constant of NiO with the rhombohedral distorted B1 structure was studied up to 141 GPa by angle-dispersive x-ray diffraction using synchrotron radiation and an imaging plate, with reference to a recent theoretical calculation within the density-functional formalism with the local-spin density approcximation. The lattice constant and , expressed in the hexagonal lattice, decrease monotonously with increasing pressure. The axial rage decreases monotonously with increasing pressure, indicating the enhancement of the rhombohedral distortion. The signiifcant change of above 60 GPa suggested by the calculation was not observed.
Ikeda, Yoshitaka; Fujita, Takaaki; Hamamatsu, Kiyotaka; Ide, Shunsuke; Imai, Tsuyoshi; Isayama, Akihiko; Iwase, Makoto; Kasugai, Atsushi; Kondoh, Takashi; Kusama, Yoshinori; et al.
AIP Conference Proceedings 485, p.279 - 287, 1999/09
no abstracts in English
Nemoto, Masahiro; Ushigusa, Kenkichi; Imai, Tsuyoshi; Ikeda, Yoshitaka; Naito, Osamu; Kusama, Yoshinori; Tobita, Kenji; Takeuchi, Hiroshi; JT-60 Team
Physical Review Letters, 67(1), p.70 - 73, 1991/07
Times Cited Count：14 Percentile：70.08(Physics, Multidisciplinary)no abstracts in English
Tsuji, Shunji; Ushigusa, Kenkichi; Ikeda, Yoshitaka; Imai, Tsuyoshi; Itami, Kiyoshi; Nemoto, Masahiro; Nagashima, Keisuke; Koide, Yoshihiko; Kawano, Yasunori; Fukuda, Takeshi; et al.
Physical Review Letters, 64(9), p.1023 - 1026, 1990/02
Times Cited Count：55 Percentile：88.38(Physics, Multidisciplinary)no abstracts in English
Imai, Tsuyoshi; Ushigusa, Kenkichi; Ikeda, Yoshitaka; Nemoto, Masahiro; Kusama, Yoshinori; Matsuoka, Mamoru; JT-60 Team
Nuclear Fusion, 30(1), p.161 - 168, 1990/01
Times Cited Count：11 Percentile：48.1(Physics, Fluids & Plasmas)no abstracts in English
