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Ito, Kimihiko*; Matsumura, Daiju; Song, C.*; Kubo, Yoshimi*
ACS Energy Letters (Internet), 7(6), p.2024 - 2028, 2022/06
Times Cited Count:1 Percentile:46.38(Chemistry, Physical)Tang, J.*; Seo, O.*; Rivera Rocabado, D. S.*; Koitaya, Takanori*; Yamamoto, Susumu*; Namba, Yusuke*; Song, C.*; Kim, J.*; Yoshigoe, Akitaka; Koyama, Michihisa*; et al.
Applied Surface Science, 587, p.152797_1 - 152797_8, 2022/06
Times Cited Count:4 Percentile:87.56(Chemistry, Physical)The hydrogen absorption and diffusion mechanisms on cube-shaped Pd nanoparticles (NPs) which are important hydrogen-storage materials were studied using X-ray photoelectron spectroscopy and DFT calculations. In the surface region, hydrogen absorption showed almost similar behavior regardless of the NPs size. It was found that the octahedral sites are more favorable than the tetrahedral sites for hydrogen occupation. We also clarified that the hydrogen atoms absorbing on the smaller-sized Pd NPs diffuse to the subsurface more actively because of the weakened Pd-H bond by the surface disordering, which plays an important role in hydrogen adsorption at a low H pressure.
Nakayoshi, Akira; Rempe, J. L.*; Barrachin, M.*; Bottomley, D.; Jacquemain, D.*; Journeau, C.*; Krasnov, V.; Lind, T.*; Lee, R.*; Marksberry, D.*; et al.
Nuclear Engineering and Design, 369, p.110857_1 - 110857_15, 2020/12
Times Cited Count:6 Percentile:38.41(Nuclear Science & Technology)Much is still not known about the end-state of core materials in each of the units at Fukushima Daiichi Nuclear Power Station (Daiichi) that were operating on March 11, 2011. The Nuclear Energy Agency of the Organization for Economic Development has launched the Preparatory Study on Analysis of Fuel Debris (PreADES) project as a first step to reduce some of these uncertainties. As part of the PreADES Task 1, relevant information was reviewed to confirm the accuracy of graphical depictions of the debris endstates at the damaged Daiichi units, which provides a basis for suggesting future debris examinations. Two activities have been completed within the PreADES Task 1. First, relevant knowledge from severe accidents at the Three Mile Island Unit 2 and the Chernobyl Nuclear Power Plant Unit 4 was reviewed, along with results from prototypic tests and hot cell examinations, to glean insights that may inform future decommissioning activities at Daiichi. Second, the current debris endstate diagrams for the damaged reactors at Daiichi were reviewed to confirm that they incorporate relevant knowledge from plant observations and from severe accident code analyses of the BSAF (Benchmark Study of the Accident at Daiichi Nuclear Power Station) 1 and 2 projects. This paper highlights Task 1 insights, which have the potential to not only inform future Decontamination and Decommissioning activities at Daiichi, but also provide important perspectives for severe accident analyses and management, particularly regarding the long term management of a damaged nuclear site following a severe accident.
Pellegrini, M.*; Herranz, L.*; Sonnenkalb, M.*; Lind, T.*; Maruyama, Yu; Gauntt, R.*; Bixler, N.*; Morreale, A.*; Dolganov, K.*; Sevon, T.*; et al.
Nuclear Technology, 206(9), p.1449 - 1463, 2020/09
Times Cited Count:27 Percentile:98.54(Nuclear Science & Technology)Song, C.*; Seo, O.*; Matsumura, Daiju; Hiroi, Satoshi*; Cui, Y.-T.*; Kim, J.*; Chen, Y.*; Tayal, A.*; Kusada, Kohei*; Kobayashi, Hirokazu*; et al.
RSC Advances (Internet), 10(34), p.19751 - 19758, 2020/05
Times Cited Count:0 Percentile:0(Chemistry, Multidisciplinary)Nakayoshi, Akira; Journeau, C.*; Rempe, J.*; Barrachin, M.*; Bottomley, D.; Nauchi, Y.*; Song, J. H.*
Proceedings of 2019 International Workshop on Post-Fukushima Challenges on Severe Accident Mitigation and Research Collaboration (SAMRC 2019) (USB Flash Drive), 6 Pages, 2019/11
Ono, Akira*; Xu, J.*; Colonna, M.*; Danielewicz, P.*; Ko, C. M.*; Tsang, M. B.*; Wang, Y,-J.*; Wolter, H.*; Zhang, Y.-X.*; Chen, L.-W.*; et al.
Physical Review C, 100(4), p.044617_1 - 044617_35, 2019/10
Times Cited Count:48 Percentile:98.64(Physics, Nuclear)International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and neutrons were packed in a 20-fm-large cube to calculate the number and energies of collisions during the time evolution. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). This study showed that time step in the calculation is one of the biggest causes of the discrepancies. For example, the calculation by JQMD comprises 1-fm/c time steps, each of which is composed of transport, scattering and decay phases. Therefore a sequence of scattering, and decay followed by another scattering in 1 fm/c cannot be considered. Moreover, in JQMD particles are labeled by sequential numbers and scattering reactions are simulated by the order. Therefore scattering between low ID numbers, that between high ID numbers and that between the first (low ID) pair is overlooked in JQMD. Above indications obtained in this study must be kept in our mind for future JQMD upgrades.
Tang, C.*; Song, Q.*; Chang, C.-Z.*; Xu, Y.*; Onuma, Yuichi; Matsuo, Mamoru*; Liu, Y.*; Yuan, W.*; Yao, Y.*; Moodera, J. S.*; et al.
Science Advances (Internet), 4(6), p.eaas8660_1 - eaas8660_6, 2018/06
Times Cited Count:27 Percentile:85.21(Multidisciplinary Sciences)Zhang, Y.-X.*; Wang, Y,-J.*; Colonna, M.*; Danielewicz, P.*; Ono, Akira*; Tsang, M. B.*; Wolter, H.*; Xu, J.*; Chen, L.-W.*; Cozma, D.*; et al.
Physical Review C, 97(3), p.034625_1 - 034625_20, 2018/03
Times Cited Count:85 Percentile:99.25(Physics, Nuclear)International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and 320 neutrons were packed in a 20-fm-large cube to calculate the number of particle-particle collisions as well as the energies of collisions during the time evolution. In addition to the calculation, their algorithms were compared. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). The results were compared with those calculated by the other 15 codes from over the world. Algorithm comparison showed that JQMD calculates collision probabilities from protons at first and collisions by neutrons are simulated later, which might be unreasonable. On the other hand, it was clarified that the calculation by JQMD agrees with those by the others. Despite the fact that some codes deviate from the average by a factor of 2, JQMD exhibited stable performance.
Ho, D. M. L.*; Nelwamondo, A. N.*; Okubo, Ayako; Ramebck, H.*; Song, K.*; Han, S.-H.*; Hancke, J. J.*; Holmgren, S.*; Jonsson, S.*; Kataoka, Osamu; et al.
Journal of Radioanalytical and Nuclear Chemistry, 315(2), p.353 - 363, 2018/02
Times Cited Count:1 Percentile:12.95(Chemistry, Analytical)The Fourth Collaborative Material Exercise (CMX-4) of the Nuclear Forensics International Technical Working Group (ITWG) registered the largest participation for this exercise in nuclear forensics, with seven of the 17 laboratories participating for the first time. In this paper, participants from five of the first-time laboratories shared their individual experience in this exercise, from preparation to analysis of samples. The exercise proved to be highly useful for testing procedures, repurposing established methods, exercising skills, and improving the understanding of nuclear forensic signatures and their interpretation trough the post-exercise review meeting.
Kristo, M. J.*; Williams, R.*; Gaffney, A. M.*; Kayzar-Boggs, T. M.*; Schorzman, K. C.*; Lagerkvist, P.*; Vesterlund, A.*; Ramebck, H.*; Nelwamondo, A. N.*; Kotze, D.*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 315(2), p.425 - 434, 2018/02
Times Cited Count:10 Percentile:76.45(Chemistry, Analytical)In a recent international exercise, 10 international nuclear forensics laboratories successfully performed radiochronometry on three low enriched uranium oxide samples, providing 12 analytical results using three different parent-daughter pairs serving as independent chronometers. The vast majority of the results were consistent with one another and consistent with the known processing history of the materials. In general, for these particular samples, mass spectrometry gave more accurate and more precise analytical results than decay counting measurements. In addition, the concordance of the U-
Pa and
U-
Th chronometers confirmed the validity of the age dating assumptions, increasing confidence in the resulting conclusions.
Cho, S.*; Hyodo, Tetsuo*; Jido, Daisuke*; Ko, C. M.*; Lee, S. H.*; Maeda, Saori*; Miyahara, Kenta*; Morita, Kenji*; Nielsen, M.*; Onishi, Akira*; et al.
Progress in Particle and Nuclear Physics, 95, p.279 - 322, 2017/07
Times Cited Count:73 Percentile:88.37(Physics, Nuclear)With upgraded detectors at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), it has become possible to measure hadrons beyond their ground states in high energy heavy ion collisions. Therefore, heavy ion collisions provide a new method for studying exotic hadrons that are either molecular states made of various hadrons or compact system consisting of muliquarks. Because their structures are related to the fundamental properties of Quantum Chromodynamics (QCD), studying exotic hadrons is currently one of the most active areas of research in hadron physics. The present review is a summary of the current understanding of a selected set of exotic candidate particles that can be potentially measured in heavy ion collisions.
Tam, D. M.*; Song, Y.*; Man, H.*; Cheung, S. C.*; Yin, Z.*; Lu, X.*; Wang, W.*; Frandsen, B. A.*; Liu, L.*; Gong, Z.*; et al.
Physical Review B, 95(6), p.060505_1 - 060505_6, 2017/02
Times Cited Count:23 Percentile:73.81(Materials Science, Multidisciplinary)Lee, C.-G.*; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki; Song, K.*
Talanta, 141, p.92 - 96, 2015/08
Times Cited Count:11 Percentile:41.41(Chemistry, Analytical)Thermal ionization mass spectrometry (TIMS) with a continuous heating technique is known as an effective method for measuring the isotope ratio in trace amounts of uranium. In this study, the analytical performance of thermal ionization mass spectrometry with a continuous heating technique was investigated using a standard plutonium solution (SRM 947). The influence of the heating rate of the evaporation filament on the precision and accuracy of the isotope ratios was examined using a plutonium solution sample at the fg level. Changing the heating rate of the evaporation filament on samples ranging from 0.1 fg to 1000 fg revealed that the influence of the heating rate on the precision and accuracy of the isotope ratios was slight around the heating rate range of 100 to 250 mA/min. All of the isotope ratios of plutonium (SRM 947), Pu/
Pu,
Pu/
Pu,
Pu/
Pu and
Pu/
Pu, were measured down to sample amounts of 70 fg. The ratio of
Pu/
Pu was measured down to a sample amount of 0.1 fg, which corresponds to a PuO
particle with a diameter of 0.2
m. Moreover, the signals of
Pu could be detected with a sample amount of 0.03 fg, which corresponds to the detection limit of
Pu of 0.006 fg as estimated by the 3
criterion.
Pu and
Am formed by the decay of
Pu could be discriminated owing to the difference in the evaporation temperature. As a result,
Pu/
Pu as well as
Pu/
Pu and
Pu/
Pu in plutonium samples could be measured by TIMS with a continuous heating technique and without any chemical separation processes.
Shigyo, Nobuhiro*; Uozumi, Yusuke*; Imabayashi, Yoichi*; Itashiki, Yutaro*; Satoh, Daiki; Kajimoto, Tsuyoshi*; Sanami, Toshiya*; Koba, Yusuke*; Takada, Masashi*; Matsufuji, Naruhiro*; et al.
JAEA-Conf 2014-002, p.81 - 87, 2015/02
Cancer therapy using heavy ion beam has been adopted as highly advanced medical treatment by reason of its clinical advantages. It has become more important to estimate the risk of secondary cancer from recent survey. During treatment, secondary particles such as neutrons and -rays are producedby heavy ion induced nuclear reactions in a patient body as well as beam delivery apparatuses. For the risk assessment of secondary cancer, it is essential to know contribution of secondary neutrons by extra dose to organs in the vicinity of the irradiated tumor because the secondary neutron has a long flight path length and gives undesired dose to normal tissues in a wide volume. The experimental data of neutron energy spectra are required for dose estimations with high accuracy. Especially, precise data around neutron energy of 1 MeV is required because neutron of the energy region has a large relative biological eectiveness. Estimation of the secondary neutron yield data is important for estimation of radiation safety on both of workers and public in treatment facilities.
Kajimoto, Tsuyoshi*; Hashiguchi, Taro*; Shigyo, Nobuhiro*; Satoh, Daiki; Uozumi, Yusuke*; Song, T. Y.*; Lee, C. W.*; Kim, J. W.*; Yang, S. C.*; Koba, Yusuke*; et al.
JAEA-Conf 2014-002, p.127 - 132, 2015/02
Particle transport Monte Carlo codes such as PHITS, FLUKA and so on are used for radiation safety design of high energy accelerators. The validity of code is confirmed by comparison with many experimental data. In this study, we report proton, deuteron, and triton production double differential cross sections (DDXs) from a graphite target by 290 MeV/nucleon Ar ions. The measured spectra are compared with those calculated by PHITS and FLUKA codes.
Yang, H. L.*; Kim, Y. S.*; Park, Y. M.*; Bae, Y. S.*; Kim, H. K.*; Kim, K. M.*; Lee, K. S.*; Kim, H. T.*; Bang, E. N.*; Joung, M.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Because the 2010 operation of Korea Superconducting Tokamak Advanced Research (KSTAR) mainly aims to achieve strongly elongated and diverted plasma, all the necessary hardware systems to provide an essential circumstance for the plasma shaping were newly installed and upgraded in 2010. In this paper, general configuration of the upgraded systems described earlier will be outlined. Moreover, several key performances and test results of the systems will be also reported in summary.
Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.
JAEA-Research 2010-019, 194 Pages, 2010/08
This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.
Kataoka, Takashi*; Kobayashi, Masaki*; Sakamoto, Yuta*; Song, G. S.*; Fujimori, Atsushi*; Chang, F.-H.*; Lin, H.-J.*; Huang, D. J.*; Chen, C. T.*; Okochi, Takuo*; et al.
Journal of Applied Physics, 107(3), p.033718_1 - 033718_7, 2010/02
Times Cited Count:51 Percentile:85.9(Physics, Applied)Kobayashi, Masaki*; Hwang, J. I.*; Song, G.*; Oki, Yasuhiro*; Takizawa, Masaru*; Fujimori, Atsushi; Takeda, Yukiharu; Fujimori, Shinichi; Terai, Kota*; Okane, Tetsuo; et al.
Physical Review B, 78(15), p.155322_1 - 155322_4, 2008/10
Times Cited Count:5 Percentile:26.74(Materials Science, Multidisciplinary)