Si-addition contributes to overcoming the strength-ductility trade-off in high-entropy alloys

Wei, D.*; Gong, W.; Tsuru, Tomohito; Lobzenko, I.; Li, X.*; Harjo, S.; Kawasaki, Takuro; Do, H.-S.*; Bae, J. W.*; Wagner, C.*; et al.

International Journal of Plasticity, 159, p.103443_1 - 103443_18, 2022/12

https://doi.org/10.1016/j.ijplas.2022.103443

DECOVALEX-2019 Task D; INBEB Final Report

Gens, A.*; Alcoverro, J.*; Blaheta, R.*; Hasal, M.*; Michalec, Z.*; Takayama, Yusuke; Lee, C.*; Lee, J.*; Kim, G. Y.*; Kuo, C.-W.*; et al.

LBNL-2001267 (Internet), 210 Pages, 2020/10

This document is the final report of Task D of the DECOVALEX-2019 project, presenting the definitions of the problems studied, approaches applied, achievements made and outstanding issues identified for future research. Task D of the DECOVALEX 2019 project is devoted to the study of the hydro-mechanical and thermo-hydro-mechanical Interactions in Bentonite Engineered Barriers. The Task is structured around two large scale in situ experiments that were subjected to well managed dismantling operations that provided direct observations of the state of the barrier after long test periods. Four teams carried out the modelling of the two experiments: Institute of Geonics, of the Czech Academy of Sciences (IGN), supported by SURAO, Czech Republic, Japan Atomic Energy Agency (JAEA), Korea Atomic Energy Research Institute (KAERI) and National Central University of Taiwan (NCU), supported by the Taipower.

Shell structure of the neutron-rich isotopes Co

Lokotko, T.*; Leblond, S.*; Lee, J.*; Doornenbal, P.*; Obertelli, A.*; Poves, A.*; Nowacki, F.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Authelet, G.*; et al.

Physical Review C, 101(3), p.034314_1 - 034314_7, 2020/03

https://doi.org/10.1103/PhysRevC.101.034314

The structures of the neutron-rich Co isotopes were investigated via () knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Level schemes were reconstructed using the coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations suggests coexistence of spherical and deformed shapes at low excitation energies in the Co isotopes.

Nuclear structure of Ni from the (,) reaction

Elekes, Z.*; Kripk, *; Sohler, D.*; Sieja, K.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Doornenbal, P.*; Obertelli, A.*; Authelet, G.*; Baba, Hidetada*; et al.

Physical Review C, 99(1), p.014312_1 - 014312_7, 2019/01

https://doi.org/10.1103/PhysRevC.99.014312

The nuclear structure of the Ni nucleus was investigated by (,) reaction using a NaI(Tl) array to detect the deexciting prompt rays. A new transition with an energy of 2227 keV was identified by and coincidences. Our shell-model calculations using the Lenzi, Nowacki, Poves, and Sieja interaction produced good candidates for the experimental proton hole states in the observed energy region, and the theoretical cross sections showed good agreement with the experimental values. Although we could not assign all the experimental states to the theoretical ones unambiguously, the results are consistent with a reasonably large Z = 28 shell gap for nickel isotopes in accordance with previous studies.

Overall approaches and experiences of first-time participants in the Nuclear Forensics International Technical Working Group's Fourth Collaborative Material Exercise (CMX-4)

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

https://doi.org/10.1007/s10967-017-5677-0

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.

CIELO collaboration summary results; International evaluations of neutron reactions on uranium, plutonium, iron, oxygen and hydrogen

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

https://doi.org/10.1016/j.nds.2018.02.003

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.

The CIELO collaboration; Progress in international evaluations of neutron reactions on Oxygen, Iron, Uranium and Plutonium

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

https://doi.org/10.1051/epjconf/201714602001

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.

Low-lying structure and shape evolution in neutron-rich Se isotopes

Chen, S.*; Doornenbal, P.*; Obertelli, A.*; Rodriguez, T. R.*; Authelet, G.*; Baba, Hidetada*; Calvet, D.*; Chteau, F.*; Corsi, A.*; Delbart, A.*; et al.

Physical Review C, 95(4), p.041302_1 - 041302_6, 2017/04

https://doi.org/10.1103/PhysRevC.95.041302

Ultra-trace analysis of plutonium by thermal ionization mass spectrometry with a continuous heating technique without chemical separation

Lee, C.-G.*; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki; Song, K.*

Talanta, 141, p.92 - 96, 2015/08

https://doi.org/10.1016/j.talanta.2015.03.060

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.

The CIELO Collaboration; Neutron reactions on H, O, Fe, U, and Pu

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

https://doi.org/10.1016/j.nds.2014.04.002

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.