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Niwa, Masakazu; Shimada, Akiomi; Asamori, Koichi; Sueoka, Shigeru; Komatsu, Tetsuya; Nakajima, Toru; Ogata, Manabu; Uchida, Mao; Nishiyama, Nariaki; Tanaka, Kiriha; et al.
JAEA-Review 2024-035, 29 Pages, 2024/09
This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2024. The objectives and contents of this research are described in detail based on the JAEA 4th Medium- and Long-term Plan (fiscal years 2022-2028). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Kobayashi, Nobuyuki*; Nakamura, Takashi*; Kondo, Yosuke*; Tostevin, J. A.*; Utsuno, Yutaka; Aoi, Nori*; Baba, Hidetada*; Barthelemy, R.*; Famiano, M. A.*; Fukuda, Naoki*; et al.
Physical Review Letters, 112(24), p.242501_1 - 242501_5, 2014/06
Times Cited Count:110 Percentile:95.00(Physics, Multidisciplinary)no abstracts in English
Nakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Tostevin, J. A.*; Utsuno, Yutaka; Aoi, Nori*; Baba, Hidetada*; Fukuda, Naoki*; Gibelin, J.*; et al.
Physical Review Letters, 112(14), p.142501_1 - 142501_5, 2014/04
Times Cited Count:83 Percentile:92.75(Physics, Multidisciplinary)no abstracts in English
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07
Times Cited Count:34 Percentile:75.82(Astronomy & Astrophysics)We report on the event structure and double helicity asymmetry () of jet production in longitudinally polarized
collisions at
= 200 GeV. Photons and charged particles were measured by the PHENIX experiment. Event structure was compared with the results from PYTHIA event generator. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order perturbative QCD calculation. We measured
= -0.0014
0.0037 at the lowest
bin and -0.0181
0.0282 at the highest
bin. The measured
is compared with the predictions that assume various
distributions.
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:194 Percentile:99.41(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:9 Percentile:51.34(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.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03
Times Cited Count:185 Percentile:98.29(Astronomy & Astrophysics)The PHENIX experiment at RHIC has measured the invariant differential cross section for production of ,
,
and
mesons in
collisions at
= 200 GeV. The spectral shapes of all hadron transverse momentum distributions are well described by a Tsallis distribution functional form with only two parameters,
and
, determining the high
and characterizing the low
regions for the spectra, respectively. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.
Nakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Aoi, Nori*; Baba, Hidetada*; Deguchi, Shigeki*; Fukuda, Naoki*; Gibelin, J.*; Inabe, Naoto*; et al.
Physical Review Letters, 103(26), p.262501_1 - 262501_4, 2009/12
Times Cited Count:221 Percentile:97.61(Physics, Multidisciplinary)no abstracts in English
Oku, Takayuki; Kikuchi, Takayuki*; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya*; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
Physica B; Condensed Matter, 404(17), p.2575 - 2577, 2009/09
Times Cited Count:8 Percentile:35.26(Physics, Condensed Matter)The microscopic determination of the magnetic moment in the FeN
nano-particles by means of polarized neutron diffraction experiment is reported. These particles had been developed by industrial researchers for use in high-density magnetic tape, and the particles were coated with proprietary nonmagnetic material. Polarized neutrons were used to measure the magnetic-nuclear interference contributions and, given the known crystal structure, the detailed analysis allowed to determine the magnetic moments on the different Fe-sites. The future perspectives of this technique using the high-intensity powder instrument in combination with pulsed magnetic high-field at J-PARC including the possible industrial application is discussed.
Onishi, Takeo*; Gelberg, A.*; Sakurai, Hiroyoshi*; Yoneda, Kenichiro*; Aoi, Nori*; Imai, Nobuaki*; Baba, Hidetada*; Von Brentano, P.*; Fukuda, Naoki*; Ichikawa, Yuichi*; et al.
Physical Review C, 72(2), p.024308_1 - 024308_7, 2005/08
Times Cited Count:21 Percentile:76.80(Physics, Nuclear)no abstracts in English
Oku, Takayuki; Kikuchi, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Kakurai, Kazuhisa; Takeda, Masayasu; Ishii, Yuya; Oitani, Seiki; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; Nishihara, Yoshikazu*
no journal, ,
Magnetization distribution maps deduced from the measurement of polarization dependent cross-sections have provided unique information in understanding of the detailed electronic configurations in mixed valence materials and molecular magnets. Because of the limited neutron flux the method has been mostly applied to single crystal studies. In the advent of strong pulsed neutron source with intense high resolution powder diffractomer the magnetization distribution measurements by means of polarized neutron powder diffraction can become common place. The introduction of the high magnetic field may extend the applicability of the method to materials requiring high saturation field. In this lecture the polarized neutron powder diffraction experiment on FeN
and
-Fe fine particles performed in the frame work of "Ibaraki Prefecture Neutron Utilization Working Subgroup on nano-magnetic materials" will be presented and the possibility of the method will be discussed.
Ito, Masayasu; Taguchi, Taketoshi; Yonekawa, Minoru; Kurosawa, Makoto; Kawamata, Kazuo; Sozawa, Shizuo; Ishihara, Masahiro
no journal, ,
JMTR-HL has been promoting the advancement of PIE meets future needs of irradiation, and has been constructing the position of basic research of nuclear energy for the purpose of realizing a research environment to support "Green Innovation " and "Life Innovation" such as measures for prolonged LWR that is a subject for study worldwide, development of Next Generation LWR, the development of radioisotopes manufacturing technology for medical use, and has been promoting the development of post-irradiation test facility that is selected by the Ministry of Education as "Cutting-Edge Research Infrastructure Projects" toward the achievement of a base for international R&D. This development has done TEM, FIB and XPS, etc. and have enabled the processing and the sample observation of irradiated material specimen of 30 MBq amount of radioactivity (in terms of cobalt).
Oku, Takayuki; Kikuchi, Takayuki; Oba, Yojiro; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Oitani, Seiki; Takeda, Masayasu; Kakurai, Kazuhisa; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Kikuchi, Takayuki; Shinohara, Takenao; Oku, Takayuki; Suzuki, Junichi; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Hagiya, Hiroyuki; Oku, Takayuki; Kira, Hiroshi; Shinohara, Takenao; Suzuki, Junichi; Takeda, Masayasu; Tamai, Yuta; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; et al.
no journal, ,
no abstracts in English
Tamai, Yuta; Nishihara, Yoshikazu*; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*
no journal, ,
no abstracts in English
Kikuchi, Takayuki; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Kikuchi, Takayuki; Shinohara, Takenao; Oku, Takayuki; Suzuki, Junichi; Kishimoto, Mikio*; Sasaki, Yuji*; Yokoyama, Makoto*; et al.
no journal, ,
The needle-shaped ferromagnetic metals are often used for the magnetic recording tapes. It is, however necessary to make small and spherical shape to increase the recording capacity and density. Recently, FeN
round nanoparticles with diameter of 20 nm were produced by Hitachi Maxell, Ltd.. But it is difficult to obtain exact magnitude by conventional magnetometer due to the laminated layer around the Fe
N
. We performed polarized neutron diffraction measurements to determine the net magnetization. The averaged diameter of samples were used in these experiments are approximately 19, 18, 17 and 15 nm. The triple-axis neutron spectrometer, TAS-1, installed at JRR-3 was used in this experiment.
Tamai, Yuta; Ishii, Yuya*; Hagiya, Hiroyuki; Kikuchi, Takayuki*; Yokoyama, Makoto*; Nishihara, Yoshikazu*; Takeda, Masayasu; Kakurai, Kazuhisa; Oku, Takayuki; Shinohara, Takenao; et al.
no journal, ,
Magnetic recording tape is widely used for a massive data storage with high reliability, and further increase of capacity, the recording density, is requested by IT organizations. The needle-shaped ferromagnetic metals has been used for the recording media. However, it is necessary to make the media a small and spherical shape to increase the recording density. We have performed the polarized neutron diffraction measurements of FeN
round-shape nanoparticles, and determined the saturation magnetic moments and averaged core size of Fe
N
nanoparticles covered by a laminate layer.