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Katabuchi, Tatsuya*; Igashira, Masayuki*; Kamada, So*; Tajika, Michihide*; Iwamoto, Nobuyuki; Kawano, Toshihiko*
Physical Review C, 108(3), p.034610_1 - 034610_12, 2023/09
Times Cited Count:0 Percentile:0.00(Physics, Nuclear)Heideman, J.*; Grzywacz, R.*; Xu, Z. Y.*; Madurga, M.*; Escher, J. E.*; Kawano, Toshihiko*; Algora, A.*; Andreyev, A. N.; 41 of others*
Physical Review C, 108(2), p.024311_1 - 024311_9, 2023/08
Times Cited Count:1 Percentile:40.52(Physics, Nuclear)Kawano, Toshihiko*; Cho, Y. S.*; Dimitriou, P.*; Filipescu, D.*; Iwamoto, Nobuyuki; Plujko, V.*; Tao, X.*; Utsunomiya, Hiroaki*; Varlamov, V.*; Xu, R.*; et al.
Nuclear Data Sheets, 163, p.109 - 162, 2020/01
Times Cited Count:104 Percentile:99.69(Physics, Nuclear)Goriely, S.*; Dimitriou, P.*; Wiedeking, M.*; Belgya, T.*; Firestone, R.*; Kopecky, J.*; Krtika, M.*; Plujko, V.*; Schwengner, R.*; Siem, S.*; et al.
European Physical Journal A, 55(10), p.172_1 - 172_52, 2019/10
Times Cited Count:75 Percentile:91.94(Physics, Nuclear)Makii, Hiroyuki; Nishio, Katsuhisa; Hirose, Kentaro; Orlandi, R.; Lguillon, R.; Ogawa, Tatsuhiko; Soldner, T.*; Kster, U.*; Pollitt, A.*; Hambsch, F.-J.*; et al.
Physical Review C, 100(4), p.044610_1 - 044610_7, 2019/10
Times Cited Count:12 Percentile:73.96(Physics, Nuclear)Utsunomiya, Hiroaki*; Iwamoto, Nobuyuki; Kawano, Toshihiko*
Kaku Deta Nyusu (Internet), (122), p.26 - 32, 2019/02
no abstracts in English
Dimitriou, P.*; Belgya, T.*; Cho, Y.-S.*; Filipescu, D.*; Firestone, R.*; Goriely, S.*; Iwamoto, Nobuyuki; Kawano, Toshihiko*; Kopecky, J.*; Krticka, M.*; et al.
EPJ Web of Conferences, 178, p.06005_1 - 06005_3, 2018/05
Times Cited Count:2 Percentile:73.36(Optics)no abstracts in English
Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Kahler, A. C.*; Talou, P.*; Plompen, A. J.*; Schillebeeckx, P.*; et al.
Nuclear Data Sheets, 148, p.189 - 213, 2018/02
Times Cited Count:72 Percentile:98.15(Physics, Nuclear)The CIELO collaboration has studied neutron cross sections on nuclides that significantly impact criticality in nuclear facilities - U, U, Pu, Fe, O and H - with the aim of improving the accuracy of the data and resolving previous discrepancies in our understanding. This multi-laboratory pilot project, coordinated via the OECD/NEA Working Party on Evaluation Cooperation (WPEC) Subgroup 40 with support also from the IAEA, has motivated experimental and theoretical work and led to suites of new evaluated libraries that accurately reflect measured data and also perform well in integral simulations of criticality. This report summarizes our results and outlines plans for the next phase of this collaboration.
Carlson, A. D.*; Pronyaev, V.*; Hale, G. M.*; Zhenpeng, C.*; Capote, R.*; Durn, I.*; Hambsch, F.-J.*; Kawano, Toshihiko*; Kunieda, Satoshi; 13 of others*
EPJ Web of Conferences, 146, p.02025_1 - 02025_4, 2017/09
Times Cited Count:4 Percentile:89.49(Nuclear Science & Technology)Evaluations are being done for the H(n,n), Li(n,t), B(n,), B(n,), C(n,n), Au(n,), U(n,f) and U(n,f) standard cross sections. Evaluations are also being done for data that are not traditional standards including: the Au(n,) cross section at energies below where it is considered a standard; reference cross sections for prompt -ray production in fast neutron-induced reactions; reference cross sections for very high energy fission cross sections; the U thermal neutron fission spectrum and the Cf spontaneous fission neutron spectrum and the thermal constants.
Capote, R.*; Hilaire, S.*; Iwamoto, Osamu; Kawano, Toshihiko*; Sin, M.*
EPJ Web of Conferences, 146, p.12034_1 - 12034_4, 2017/09
Times Cited Count:6 Percentile:94.69(Nuclear Science & Technology)Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Kahler, A. C.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Pigni, M.*; Dunn, M.*; Leal, L.*; et al.
EPJ Web of Conferences, 146, p.02001_1 - 02001_9, 2017/09
Times Cited Count:6 Percentile:94.69(Nuclear Science & Technology)The CIELO collaboration has studied neutron cross sections on nuclides (O, Fe, U and Pu) that significantly impact criticality in nuclear technologies with the aim of improving the accuracy of the data and resolving previous discrepancies in our understanding. This multi-laboratory pilot project, coordinated via the OECD/NEA Working Party on Evaluation Cooperation (WPEC) Subgroup 40 with support also from the IAEA, has motivated experimental and theoretical work and led to suites of new evaluated libraries that accurately reflect measured data and also perform well in integral simulations of criticality.
Kunieda, Satoshi; Shibata, Keiichi; Fukahori, Tokio; Kawano, Toshihiko*; Paris, M.*; Hale, G.*
JAEA-Conf 2015-003, p.33 - 38, 2016/03
We present recent progress of nuclear data evaluation method in the resolved resonance range. Our multi-channel R-matrix code now includes photon-channel and computational capability of charged-particle elastic scattering. We also present the physical constraint from the theory in the analysis of experimental data. Example analysis results are shown for Be and O compound system. Finally, perspectives are discussed toward the advancement of nuclear data in the resonance region including those for medium-heavy nuclei.
Kunieda, Satoshi; Kawano, Toshihiko*; Paris, M.*; Hale, G. M.*; Shibata, Keiichi; Fukahori, Tokio
Nuclear Data Sheets, 123, p.159 - 164, 2015/01
Times Cited Count:7 Percentile:45.26(Physics, Nuclear)The collision matrix in the R-matrix theory is unitary, hence theory brings strong constraints to behavior of the parameters. An unitarity-imposed R-matrix analysis is carried out for O system to evaluate O neutron cross-sections in the resolved resonance range. Covariance matrices are also estimated both for the cross-sections and angular distributions with a deterministic method. Present results mirror the nature in the theory as well as experimental information.
Kunieda, Satoshi; Kawano, Toshihiko*; Paris, M.*; Hale, G. M.*; Shibata, Keiichi; Fukahori, Tokio
NEA/NSC/DOC(2014)13 (Internet), p.33 - 39, 2014/07
There still remain differences among measured data, which makes the evaluated cross-sections uncertain, and which consequently affects some integral calculation. O is one of the important nuclei in the nuclear application, but such kinds of issues appears in elastic-scattering and (n,) reaction cross-sections. Purpose of this study is to solve those issues as they are common concerns in the world. We present estimated cross sections and their covariance data which are "physically" constrained by the R-matrix theory. The differences between the estimated and the measured cross-sections will be also discussed.
Chadwick, M. B.*; Dupont, E.*; Bauge, E.*; Blokhin, A.*; Bouland, O.*; Brown, D. A.*; Capote, R.*; Carlson, A. D.*; Danon, Y.*; De Saint Jean, C.*; et al.
Nuclear Data Sheets, 118, p.1 - 25, 2014/04
Times Cited Count:108 Percentile:98.42(Physics, Nuclear)CIELO (Collaborative International Evaluated Library Organization) provides a new working paradigm to facilitate evaluated nuclear reaction data advances. It brings together experts from across the international nuclear reaction data community to identify and document discrepancies among existing evaluated data libraries, measured data, and model calculation interpretations, and aims to make progress in reconciling these discrepancies to create more accurate ENDF-formatted files. The focus will initially be on a small number of the highest-priority isotopes, namely H, O, Fe, U, and Pu. This paper identifies discrepancies between various evaluations of the highest priority isotopes. The evaluated data for these materials in the existing nuclear data libraries are reviewed, and some integral properties are given. The paper summarizes a program of nuclear science and computational work needed to create the new CIELO nuclear data evaluations.
Kunieda, Satoshi; Kawano, Toshihiko*; Paris, M.*; Hale, G. M.*; Shibata, Keiichi; Fukahori, Tokio
Nuclear Data Sheets, 118, p.250 - 253, 2014/04
Times Cited Count:13 Percentile:63.98(Physics, Nuclear)Oxygen is one of the most important materials in nuclear applications. However, there are big discrepancies among experimental and evaluated data in O() cross section. Also, there are increasing demands for giving uncertainties in evaluated cross section to estimate the margin of integral calculations. We analyzed experimental cross sections with R-matrix theory, and estimated cross sections with their uncertainties. In this analysis, not only the neutron but also an inverse reactions were included. The systematic uncertainties were also considered for each measurement. The resulting cross sections and uncertainties mirror both experimental and theoretical knowledges.
Kunieda, Satoshi; Haight, R. C.*; Kawano, Toshihiko*; Chadwick, M. B.*; Sterbenz, S. M.*; Bateman, F. B.*; Wasson, O. A.*; Grimes, S. M.*; Maier-Komor. P.*; Vonach, H.*; et al.
Physical Review C, 85(5), p.054602_1 - 054602_10, 2012/05
Times Cited Count:25 Percentile:75.56(Physics, Nuclear)Neutron reactions that produce alpha-particles have been investigated for energies from threshold to 150 MeV on elemental chromium, iron, Co and Ni. The cross sections were measured at the Los Alamos Neutron Science Center by direct observation of alpha-particles. The model calculations are made for statistical and pre-equilibrium processes. This study particularly focuses on the pre-equilibrium cluster emission, which is described by the clustering exciton model of Iwamoto and Harada. We calculate the alpha-particle formation factors numerically without any approximations that appeared in the original model. The calculated alpha-particle production cross sections agree well with the measured data, except for the Cr case. With a simple sensitivity study for the level density parameters, it is reported that relatively small changes in the level density parameters improve reproduction of experimental data significantly.
Kunieda, Satoshi; Kawano, Toshihiko*; Chadwick, M. B.*; Fukahori, Tokio; Watanabe, Yukinobu*
EPJ Web of Conferences, 21, p.09003_1 - 09003_8, 2012/02
Times Cited Count:2 Percentile:61.78(Physics, Nuclear)The clustering exciton model of Iwamoto and Harada is applied to the analysis of pre-equilibrium energy spectra for medium-to-heavy nuclei up to 200 MeV. In this work, we calculate alpha-particle formation factors without any approximations that appear in the original model. The clustering process is also considered in both the primary and second pre-equilibrium emissions. We optimize the exciton and the clustering model parameters simultaneously by looking at the experimental and energy spectra. The experimental alpha-particle spectra are well reproduced with a unique set of clustering model parameters, which is independent of incident neutrons/protons. The present analysis also implies that the clustering model parameter is not so different between the medium and heavy nuclei. Our calculations reproduce experimental data generally well up to the incident energy of 150 MeV, but underestimations are seen above this energy.
Chadwick, M. B.*; Herman, M.*; Obloinsk, P.*; Dunn, M. E.*; Danon, Y.*; Kahler, A. C.*; Smith, D. L.*; Pritychenko, B.*; Arbanas, G.*; Arcilla, R.*; et al.
Nuclear Data Sheets, 112(12), p.2887 - 2996, 2011/12
Times Cited Count:2158 Percentile:99.99(Physics, Nuclear)The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. It features extension of covered nuclei, covariance data for 190 nuclei, R-matrix analyses of neutron reactions on light nuclei, updates for some medium-heavy and actinoid nuclei, etc. Criticality benchmark tests with a transport simulation code MCNP shows improved performances.
Chiba, Satoshi; Koura, Hiroyuki; Hayakawa, Takehito; Maruyama, Toshiki; Kawano, Toshihiko*; Kajino, Toshitaka*
Physical Review C, 77(1), p.015809_1 - 015809_7, 2008/01
Times Cited Count:26 Percentile:79.56(Physics, Nuclear)We calculate the direct and semi-direct (DSD) components of the neutron capture cross sections for a series of tin isotopes and compare them with the Hauser-Feshbach (HF) contribution in the energy region of astrophysical interests. It was found that the HF component, which is known to be dominant for isotopes in the vicinity of the stability line, drops off rapidly for isotope Sn and toward more neutron-rich ones, while the DSD component decreases only smoothly. As a consequence, the direct portion of the DSD component comes to give the largest contribution to the total (,) cross section below a few MeV. Therefore, the direct capture process modifies the astrophysical (,) reaction rates for these neutron-rich isotopes to a great extent. The reason of the difference in the isotopic dependence between the HF and DSD components is discussed, and its implication for the -process nucleosynthesis is given.