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Tsuru, Tomohito; Itakura, Mitsuhiro; Yamaguchi, Masatake; Watanabe, Chihiro*; Miura, Hiromi*
Computational Materials Science, 203, p.111081_1 - 111081_9, 2022/02
Times Cited Count:7 Percentile:59.22(Materials Science, Multidisciplinary)The deformation mode of some titanium (Ti) alloys differs from that of pure Ti due to the presence of alloying elements in -phase. Herein, we investigated all possible slip modes in pure Ti and the effects of Al and V solutes as typical additive elements on the dislocation motion in
-Ti alloys using density functional theory (DFT) calculations. The stacking fault (SF) energies in possible slip planes indicated that both Al and V solutes reduce the SF energy in the basal plane and, in contrast, the Al solute increases the SF energy particularly in the prismatic plane. DFT calculations were subsequently performed to simulate dislocation core structures. The energy landscape of the transition between all possible dislocation core structures and the barriers for dislocation glide in various slip planes clarified the nature of dislocation motion in pure Ti. (i) the energy of prismatic core is higher than most stable pyramidal core, and thereby dislocations need to overcome the energy barrier of the cross-slip (22.8 meV/b) when they move in the prismatic plane, (ii) the energy difference between the prismatic and basal cores is larger (127 meV/b), that indicates the basal slip does not activate, (iii) however, the Peierls barrier for motion in the basal plane is not as high (16 meV/b). Direct calculations for the dislocation core around solutes revealed that both Al and V solutes facilitate dislocation motion in the basal plane by reducing the energy difference between the prismatic and basal cores. The effect of solutes characterizes the difference in the deformation mode of pure Ti and
-Ti alloys.
Yamaguchi, Atsushi*; Muramatsu, Haruka*; Hayashi, Tasuku*; Yuasa, Naoki*; Nakamura, Keisuke; Takimoto, Misaki; Haba, Hiromitsu*; Konashi, Kenji*; Watanabe, Makoto*; Kikunaga, Hidetoshi*; et al.
Physical Review Letters, 123(22), p.222501_1 - 222501_6, 2019/11
Times Cited Count:31 Percentile:88.31(Physics, Multidisciplinary)Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Times Cited Count:16 Percentile:73.87(Physics, Multidisciplinary)Excitation functions of quasielastic scattering cross sections for the Ca +
Pb,
Ti +
Pb, and
Ca +
Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the
Ca +
Pb and
Ti +
Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the
Ca +
Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Kaji, Daiya*; Morita, Kosuke*; Morimoto, Koji*; Haba, Hiromitsu*; Asai, Masato; Fujita, Kunihiro*; Gan, Z.*; Geissel, H.*; Hasebe, Hiroo*; Hofmann, S.*; et al.
Journal of the Physical Society of Japan, 86(3), p.034201_1 - 034201_7, 2017/03
Times Cited Count:24 Percentile:81.31(Physics, Multidisciplinary)The fusion reaction of Ca +
Cm
Lv
was studied using the gas-filled recoil-ion separator GARIS at RIKEN. A total of seven
and spontaneous-fission decay chains were observed, which would originate from the reaction products of the element 116,
Lv and
Lv. Decay properties observed in the chains are in good agreement with the previously published ones. However, one of the chains showed a discrepancy, indicating the new spontaneous-fission branch in
Cn or the production of the new isotope
Lv.
Noda, Yohei*; Koizumi, Satoshi*; Masui, Tomomi*; Mashita, Ryo*; Kishimoto, Hiromichi*; Yamaguchi, Daisuke; Kumada, Takayuki; Takata, Shinichi; Oishi, Kazuki*; Suzuki, Junichi*
Journal of Applied Crystallography, 49(6), p.2036 - 2045, 2016/12
Times Cited Count:17 Percentile:76.89(Chemistry, Multidisciplinary)Yamaguchi, Hiromi
Genshiryoku, Ryoshi, Kakuyugo Jiten, 3, p.160 - 161, 2014/12
no abstracts in English
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:48.74(Physics, Fluids & Plasmas)Sakai, Takaaki; Yamano, Hidemasa; Tanaka, Masaaki; Ono, Ayako; Ohshima, Hiroyuki; Kaneko, Tetsuya*; Hirota, Kazuo*; Sago, Hiromi*; Xu, Y.*; Iwamoto, Yukiharu*; et al.
Proceedings of 15th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-15) (USB Flash Drive), 13 Pages, 2013/05
The development of flow-induced vibration evaluation methodology has reached a milestone that separate-effect experimental data under a high Reynolds number regime including swirl and deflected inflow conditions are available for the validation of the methodology. On the other hand, technical standards are desirable to be documented for designers of sodium-cooled fast reactors. From such a background, the documentation of a flow-induced vibration design guideline has been made for the hot-leg piping of Japan sodium-cooled fast reactor. This paper describes the design guideline of the flow-induced vibration evaluation methodology, which has been informed from main separate-effect experiments, as well as supplemental interpretation for the guideline.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.
Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10
Times Cited Count:161 Percentile:97.32(Physics, Multidisciplinary)An isotope of the 113th element, 113, was produced in a nuclear reaction with a
Zn beam on a
Bi target. We observed six consecutive
decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of
Db and
Lr both in decay energies and decay times. This indicates that the present decay chain consisted of
113,
Rg (Z = 111),
Mt (Z = 109),
Bh (Z = 107),
Db (Z = 105), and
Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope
113, of the 113th element.
Sato, Nozomi; Haba, Hiromitsu*; Ichikawa, Takatoshi*; Kaji, Daiya*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozeki, Kazutaka*; Sumita, Takayuki*; Yoneda, Akira*; et al.
Journal of the Physical Society of Japan, 80(9), p.094201_1 - 094201_7, 2011/09
Times Cited Count:15 Percentile:65.9(Physics, Multidisciplinary)Decay properties of Hs and
Hs produced in the
Pb(
Fe,
) [
=1, 2] reactions were studied using a gas-filled recoil ion separator at the linear accelerator facility of RIKEN. A total of 6 decay chains were assigned to
Hs. Cross sections for the
Hs production in the
Pb(
Fe,
) and
Pb(
Fe,
) reactions were measured to be
pb and
pb, respectively. The isotope
Hs decayed with a half-life of
ms by
-particle emission and spontaneous fission. The
-particle energy of
Hs was observed at 10.61
0.04 and 10.80
0.08 MeV. The spontaneous fission branch of
Hs was found to be
.
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:99.44(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.
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:46.61(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.
Maekawa, Tatsuyuki*; Yamaguchi, Hiromi
Nihon Genshiryoku Gakkai Wabun Rombunshi, 8(3), p.264 - 278, 2009/09
A novel alpha radioactivity monitor using ionized air transport technology has been developed for future constitution of "Clearance Level" for Uranium and TRU radioactive waste. This technology will bring parading shift on the alpha-ray measurement such as converting "closely contacting and scanning measurement" to "remotely measurement in the block", and drastically improve the efficiency of measurement operation. In this article, the origin and chronicle of this technology were simply explained and the newest our accomplishment was described. Furthermore, using measurement data obtained in our development process, measurement and evaluation examples of alpha radioactivity were shown for practical operations as informative guides. We hope that this technology will be widely endorsed as the practical method for the alpha clearance measurement in near future.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sato, Nozomi*; Sumita, Takayuki*; Yoneda, Akira*; Ichikawa, Takatoshi*; et al.
Journal of the Physical Society of Japan, 78(6), p.064201_1 - 064201_6, 2009/06
Times Cited Count:30 Percentile:78.77(Physics, Multidisciplinary)Decay properties of an isotope Bh and its daughter nucleus
Db produced by the
Cm(
Na,5
) reaction were studied by using a gas-filled recoil separator coupled with a position-sensitive semiconductor detector.
Bh was clearly identified from the correlation of the known nuclide,
Db. The obtained decay properties of
Bh and
Db are consistent with those observed in the
113 chain, which provided further confirmation of the discovery of
113.
Sasaki, Toshiki; Sone, Tomoyuki; Koyama, Hayato; Yamaguchi, Hiromi
Journal of Nuclear Science and Technology, 46(3), p.232 - 238, 2009/03
Times Cited Count:15 Percentile:65.53(Nuclear Science & Technology)A demonstration scale steam reforming treatment system was tested for the treatment of waste tri-n-butyl phosphate/n-dodecane contaminated uranium and simulated halogenated organic wastes stored in the Japan Atomic Energy Agency. The steam reforming treatment system was designed for the organic waste which produced a lot of acidic compounds by incineration and gave severe damage to incinerators. The system comprises a gasification process for decontamination by pyrolysis and steam reforming in a gasification chamber and a destruction process by oxidation with heated air in a submerged combustion type reactor for corrosion prevention. Wastes were reduced by 98 to 99.4% in weight during the treatment without any trouble by the acidic compounds. Almost all uranium was retained in the gasification chamber and uranium concentration of secondary waste water was very low that can permit the discharge of the neutralized waste water in the river.
Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Ozeki, Kazutaka*; Haba, Hiromitsu*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; et al.
Journal of the Physical Society of Japan, 78(3), p.035003_1 - 035003_2, 2009/03
A new hassium isotopes Hs is directly produced for the first time. The experiment was performed at the linear accelerator (RILAC) facility in RIKEN (the Institute of Physical and Chemical Research) from Jun. 19 to 25. In the 25-h irradiation of
Fe on
Pb and 46-h irradiation of
Fe on
Pb, 8 decay chains and 1 decay chain, respectively, were observed. All decay chains were assigned to subsequent decays from
Hs. The half-life of
Hs is 0.60
ms. In this experiment, the total beam dose was
ions for
Fe and
ions for
Fe. The production cross section corresponding to 8 decay events and 1 decay chain was deduced to be 21
pb and 1.6
pb by assuming that the transmission of the system is 80%.
Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Ozeki, Kazutaka*; Haba, Hiromitsu*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; et al.
Journal of the Physical Society of Japan, 78(3), p.035003_1 - 035003_2, 2009/03
Times Cited Count:3 Percentile:26.57(Physics, Multidisciplinary)A new neutron deficient hassium (=108) isotope of
Hs was identified via two different reactions of
Pb(
Fe,n) and
Pb(
Fe,n) by using a gas-filled recoil separator GARIS at June 2008. During the 25-h irradiation of
Pb with the
Fe beam and 46-h irradiation of
Pb with the
Fe beam, 8 decay chains and 1 decay chain, respectively, have been observed. The half-life of
Hs is 0.60
ms. In this experiment, the total beam doses of the Fe and
Fe was 4.1
10
ions and 6.2
10
ions, respectively. The production cross sections corresponding to the 8 decay chains and 1 decay chain have been deduced to be 21
pb and 1.6
pb by assuming the transmission of the system to be 80%.
Sakakibara, Tetsuro; Aoyama, Yoshio; Yamaguchi, Hiromi; Sasaki, Naoto*; Nishikawa, Takeshi*; Murata, Minoru*; Park, J.*; Taniguchi, Shoji*; Fujita, Michiru*; Fukuda, Tomoyuki*; et al.
Proceedings of International Waste Management Symposium 2009 (WM '09) (CD-ROM), 15 Pages, 2009/03
The volume reduction treatment of solid waste system by ultra-high frequency induction furnace (UHFIF) was developed from FY2005 to FY2007. Basic data for melting performance were collected by non-radioactive experiments using the bench scale UHFIF with a crucible capacity of 10 liters. Based on the obtained data, engineering specifications were evaluated for a demonstration scale UHFIF with a crucible capacity of 30 liters. A new demonstration scale UHFIF was constructed and melting experiments of surrogate wastes were carried out by this furnace. It was confirmed that the demonstration scale UHFIF can melt ferrous metal, ceramics and aluminum all together and stabilize aluminum by oxidation to alumina. Density, chemical composition, and surface condition of the solidified substances were analyzed, and homogeneity of the solidified substances was confirmed. Melting behavior in the demonstration scale UHFIF was analyzed by computer simulation and simulation results agreed well with the experimental ones. From the design study for a full scale UHFIF with a crucible capacity of 100 liters, basic specifications were evaluated for the full scale UHFIF. Based on the obtained specification, melting behavior in the full scale UHFIF was analyzed by computer simulation.
Sato, Nozomi*; Haba, Hiromitsu*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Kaji, Daiya*; Koura, Hiroyuki; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozawa, Akira*; et al.
RIKEN Accelerator Progress Report, Vol.42, P. 16, 2009/00
New Decay Properties of Hs and its
-decay daughter nuclei were studied by using reactions of
Pb(
Fe,2n) and
Pb(
Fe,n) by using a gas-filled recoil ion separator, GARIS at RIKEN. We observed three correlated events in irradiation of
Fe on
Pb, and eight events in irradiation of
Fe on
Pb. A half-life was deduced to be 0.90
. We assigned these eleven events to be the decays of
Hs. We found different decay-chain events of
Hs from a previous report. One is a long-lived
-decay of
Sg with 180
ms of half-life. Another is a long-lived
-decay of
Rf with 10.4
s of half-life. For
Sg and
Rf, the decay of such a long-lived state have not been reported. These are the first observations of isomerism in
Sg and
Rf.