Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 174

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

$$alpha$$-clustering in atomic nuclei from first principles with statistical learning and the Hoyle state character

Otsuka, Takaharu; Abe, Takashi*; Yoshida, Toru*; Tsunoda, Yusuke*; Shimizu, Noritaka*; Itagaki, Naoyuki*; Utsuno, Yutaka; Vary, J. P.*; Maris, P.*; Ueno, Hideki*

Nature Communications (Internet), 13(1), p.2234_1 - 2234_10, 2022/04

 Times Cited Count:0 Percentile:0.01(Multidisciplinary Sciences)

no abstracts in English

Journal Articles

A First glimpse at the shell structure beyond $$^{54}$$Ca; Spectroscopy of $$^{55}$$K, $$^{55}$$Ca, and $$^{57}$$Ca

Koiwai, Takuma*; Wimmer, K.*; Doornenbal, P.*; Obertelli, A.*; Barbieri, C.*; Duguet, T.*; Holt, J. D.*; Miyagi, Takayuki*; Navr$'a$til, P.*; Ogata, Kazuyuki*; et al.

Physics Letters B, 827, p.136953_1 - 136953_7, 2022/04

 Times Cited Count:0

no abstracts in English

JAEA Reports

Research on factor analysis and technical process for achieving denuclearization; Case study and factor analysis of denuclearization

Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori

JAEA-Review 2021-076, 108 Pages, 2022/03

JAEA-Review-2021-076.pdf:3.89MB

In order to find ways to lead the denuclearization successfully, effectively, and efficiently in the future, "Research on factor analysis and technical process for achieving denuclearization" has been conducted since 2018. This report covers the first half of the research, namely "Factor analysis for denuclearization", summarizing the results of the case study and factor analysis of denuclearization. First, South Africa, Iraq, Libya, Ukraine, Kazakhstan, Belarus, North Korea, Iran and Syria were selected as the initial research target countries, and the history of nuclear development as well as characteristics of denuclearization in each country were investigated and analyzed. Next, in order to consider the measures for the international community to lead the denuclearization of the target countries, eight main denuclearization factors ((1) Motivation for nuclear development, (2) Internal and external situation at the time of the denuclearization, (3) Progress of nuclear development, (4) Effects of sanctions, (5) International framework for denuclearization, (6) Incentives for denuclearization, (7) Denuclearization method, (8) Verification method/verifier) were found out. Finally, the contents of each denuclearization factor from (1) to (8)) in above target countries except Syria were analyzed, together with whether each factor was effective for denuclearization or not. In addition, in order to lead denuclearization effectively and efficiently, what should be done in relation to the eight factors were considered. These results are expected to serve as a basis for research on the technological process of denuclearization, and to help considering the way to accomplish denuclearization.

JAEA Reports

Research on factor analysis and technical process for achieving denuclearisation; Investigation on Libya's case

Tamai, Hiroshi; Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Nakatani, Takayoshi; Suda, Kazunori

JAEA-Review 2021-073, 19 Pages, 2022/03

JAEA-Review-2021-073.pdf:1.51MB

As a part of "Research on Factor Analysis and Technical Process for Achieving Denuclearisation", investigation on Libya's cases of nuclear development and denuclearisation, and analysis of its characteristics have been conducted. Libya had been suspected that dictator Qadaffi had an interest in the acquisition of weapons of mass destruction (WMD) since early 1970s after his revolution. US and UK intelligence were focusing on Libya's situation; however, actual status was not revealed for a long time. In 1980s, Libya faced to economic exhaustion due to sanctions from the international community against Libya's supporting terrorism. Libya decided to abandon WMD development and its denuclearisation in early 2000s. Several factors to prompt Libya's decisions can be highlighted; economic sanctions; witnessing regime collapse of President Hussein due to Iraq War who aimed at WMD; revealing secret procurement of centrifuge equipment through the inspection of German-flagged ships by US. Libya's denuclearisation was rapidly implemented to prevent Libya from reverting to nuclear development through well-coordinated roles among main players, quick decisions by Libyan side, and warning effect of Iraqi case. International Atomic Energy Agency (IAEA) played a central role in the verification of all related facilities and activities in Libya. Through safeguards activities beyond those permitted by Additional Protocol (AP), IAEA evaluated the whole Libya's nuclear programme. The denuclearisation was successfully completed by removal of nuclear materials and related equipment from Libya. It was also revealed that Libya's technological capabilities had not well developed to utilize procured materials and equipment. Libya's case is regarded in the international community as a good practice of denuclearisation. On the other hand, Qadaffi administration was overthrown by the democratisation movement that occurred after denuclearisation. It might be understood as a miserable end

Journal Articles

Study of rational safeguards for the treatment of radioactive waste containing nuclear materials

Nakatani, Takayoshi; Shimizu, Ryo; Tazaki, Makiko; Kimura, Takashi; Tamai, Hiroshi; Suda, Kazunori

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11

Currently, JAEA is in the advancing of decommissioning own nuclear facilities, and some facilities have been handling nuclear materials. In decommissioning, it is necessary to consider rational methods while keeping nuclear non-proliferation and transparency, including treatment of radioactive waste generated from these facilities and methods for terminating safeguards. In this study, we considered the above issues regarding waste treatment with reference to the guidance of Safeguards by Design (SBD) published by the International Atomic Energy Agency (IAEA).

Journal Articles

Investigation and consideration of the requirements and issues from the viewpoint of the IAEA safeguards for the decommissioning of nuclear facilities

Kimura, Takashi; Fukui, Yasuhito; Tazaki, Makiko; Nakatani, Takayoshi; Shimizu, Ryo; Suda, Kazunori

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11

no abstracts in English

Journal Articles

Research on factor analysis for achieving denuclearization, 10; Summary of research; Analysis of denuclearization factors of target countries and lessons learned from the analysis

Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Nakatani, Takayoshi; Tamai, Hiroshi; Suda, Kazunori

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11

no abstracts in English

Journal Articles

Research on factor analysis for achieving denuclearization, 11; Concept of the disabling nuclear facilities in denuclearization

Shimizu, Ryo; Tazaki, Makiko; Kimura, Takashi; Nakatani, Takayoshi; Suda, Kazunori

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 3 Pages, 2021/11

no abstracts in English

Journal Articles

Ground-state properties of light $$4n$$ self-conjugate nuclei in ${it ab initio}$ no-core Monte Carlo shell model calculations with nonlocal $$NN$$ interactions

Abe, Takashi*; Maris, P.*; Otsuka, Takaharu*; Shimizu, Noritaka*; Utsuno, Yutaka; Vary, J. P.*

Physical Review C, 104(5), p.054315_1 - 054315_22, 2021/11

 Times Cited Count:4 Percentile:80.9(Physics, Nuclear)

no abstracts in English

Journal Articles

Investigation of the ground-state spin inversion in the neutron-rich $$^{47,49}$$Cl isotopes

Linh, B. D.*; Corsi, A.*; Gillibert, A.*; Obertelli, A.*; Doornenbal, P.*; Barbieri, C.*; Chen, S.*; Chung, L. X.*; Duguet, T.*; G$'o$mez-Ramos, M.*; et al.

Physical Review C, 104(4), p.044331_1 - 044331_16, 2021/10

 Times Cited Count:1 Percentile:46.35(Physics, Nuclear)

no abstracts in English

JAEA Reports

Carrying-out of whole nuclear fuel materials in Plutonium Research Building No.1

Inagawa, Jun; Kitatsuji, Yoshihiro; Otobe, Haruyoshi; Nakada, Masami; Takano, Masahide; Akie, Hiroshi; Shimizu, Osamu; Komuro, Michiyasu; Oura, Hirofumi*; Nagai, Isao*; et al.

JAEA-Technology 2021-001, 144 Pages, 2021/08

JAEA-Technology-2021-001.pdf:12.98MB

Plutonium Research Building No.1 (Pu1) was qualified as a facility to decommission, and preparatory operations for decommission were worked by the research groups users and the facility managers of Pu1. The operation of transportation of whole nuclear materials in Pu1 to Back-end Cycle Key Element Research Facility (BECKY) completed at Dec. 2020. In the operation included evaluation of criticality safety for changing permission of the license for use nuclear fuel materials in BECKY, cask of the transportation, the registration request of the cask at the institute, the test transportation, formulation of plan for whole nuclear materials transportation, and the main transportation. This report circumstantially shows all of those process to help prospective decommission.

Journal Articles

Analysis on essential factors for successful denuclearization

Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori

Proceedings of INMM & ESARDA Joint Virtual Annual Meeting (Internet), 10 Pages, 2021/08

JAEA Reports

Proceedings of debriefing session on JAEA's Underground Research Laboratory Projects, 2020

Shimizu, Mayuko; Amano, Kenji; Mizuno, Takashi; Hama, Katsuhiro

JAEA-Review 2021-004, 92 Pages, 2021/07

JAEA-Review-2021-004.pdf:10.33MB

Japan Atomic Energy Agency (JAEA) has been conducting research and development (R&D) on geological disposal technology in order to establish a scientific and technological basis for the geological disposal of HLW. "Debriefing Session on JAEA's Underground Research Laboratory" was held online on December 1, 2020 by live stream on YouTube, in order to widely disseminate the results of R&D themes ("Important issues") that we have been focusing on from fiscal year 2015 to 2019 and the plans for 2020 and beyond, and to further enhance the research plan. This document summarizes the overview of the debriefing session and the presentation materials.

Journal Articles

Radioactivity and radionuclides in deciduous teeth formed before the Fukushima-Daiichi Nuclear Power Plant accident

Takahashi, Atsushi*; Chiba, Mirei*; Tanahara, Akira*; Aida, Jun*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Murakami, Shinobu*; Koarai, Kazuma; Ono, Takumi*; Oka, Toshitaka; et al.

Scientific Reports (Internet), 11(1), p.10355_1 - 10355_11, 2021/05

 Times Cited Count:4 Percentile:63.59(Multidisciplinary Sciences)

Journal Articles

Study of neutron-nuclear spin correlation term with a polarized Xe target

Sakai, Kenji; Oku, Takayuki; Okudaira, Takuya; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Hayashida, Hirotoshi*; Kakurai, Kazuhisa*; Shimizu, Hirohiko*; Hirota, Katsuya*; et al.

JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03

In neutron fundamental physics, study of correlation term $${bf s}cdot{bf I}$$ of a neutron spin $${bf s}$$ and a target nuclear spin $${bf I}$$ is important because $${bf s}cdot{bf I}$$ term interferes to parity non-conserving (PNC) and time reversal non-conserving terms. For this study, a xenon (Xe) is an interesting nucleus because it has been observed an enhancement of PNC effect around neutron resonance peaks, and polarizes up to $$ sim 10^{-1}$$ by using a spin exchange optical pumping (SEOP) method. We would plan to develop a polarized Xe gas target with a compact in-situ SEOP system, and to study $${bf s}cdot{bf I}$$ term by utilizing epithermal neutron beams supplied from a high intense pulsed spallation neutron source. As the first step, we attempted to measure neutron polarizing ability caused by $${bf s}cdot{bf I}$$ term at a 9.6 eV s-wave resonance peak of $$^{129}$$Xe at BL10 in MLF, by detecting change $$Delta R$$ of ratio between neutron transmissions with the polarized and unpolarized Xe target. After demonstrating that our apparatus could detect small change ($$Delta R_{rm DB} , {approx},10^{-2}$$) of neutron transmissions caused by Doppler broadening effect, a signified value of $$Delta R$$ has been obtained as preliminary results. For analyzing the obtained $$Delta R$$ in detail, we are improving our nuclear magnetic resonance and electron paramagnetic resonance systems for evaluating Xe polarization independently of neutron beams.

Journal Articles

Quasifree neutron knockout reaction reveals a small $$s$$-Orbital component in the Borromean nucleus $$^{17}$$B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

 Times Cited Count:19 Percentile:98.17(Physics, Multidisciplinary)

A quasifree ($$p$$,$$pn$$) experiment was performed to study the structure of the Borromean nucleus $$^{17}$$B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for $$1s_{1/2}$$ and $$0d_{5/2}$$ orbitals, and a surprisingly small percentage of 9(2)% was determined for $$1s_{1/2}$$. Our finding of such a small $$1s_{1/2}$$ component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in $$^{17}$$B. The present work gives the smallest $$s$$- or $$p$$-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of $$s$$ or $$p$$ orbitals is not a prerequisite for the occurrence of a neutron halo.

Journal Articles

$$N$$ = 32 shell closure below calcium; Low-lying structure of $$^{50}$$Ar

Cort$'e$s, M. L.*; Rodriguez, W.*; Doornenbal, P.*; Obertelli, A.*; Holt, J. D.*; Men$'e$ndez, J.*; Ogata, Kazuyuki*; Schwenk, A.*; Shimizu, Noritaka*; Simonis, J.*; et al.

Physical Review C, 102(6), p.064320_1 - 064320_9, 2020/12

 Times Cited Count:4 Percentile:65.18(Physics, Nuclear)

Low-lying excited states in the $$N$$ = 32 isotope $$^{50}$$Ar were investigated by in-beam $$gamma$$-ray spectroscopy following proton- and neutron-knockout, multinucleon removal, and proton inelastic scattering at the RIKEN Radioactive Isotope Beam Factory. The energies of the two previously reported transitions have been confirmed, and five additional states are presented for the first time, including a candidate for a 3$$^{-}$$ state. The level scheme built using $$gamma$$ $$gamma$$ coincidences was compared to shell-model calculations in the $$sd-pf$$ model space and to ${it ab initio}$ predictions based on chiral two- and three-nucleon interactions. Theoretical proton- and neutron-knockout cross sections suggest that two of the new transitions correspond to 2$$^{+}$$ states, while the previously proposed 4$$^{+}_{1}$$ state could also correspond to a 2$$^{+}$$ state.

Journal Articles

Dynamics of proteins with different molecular structures under solution condition

Inoue, Rintaro*; Oda, Takashi*; Nakagawa, Hiroshi; Tominaga, Taiki*; Saio, Tomohide*; Kawakita, Yukinobu; Shimizu, Masahiro*; Okuda, Aya*; Morishima, Ken*; Sato, Nobuhiro*; et al.

Scientific Reports (Internet), 10, p.21678_1 - 21678_10, 2020/12

 Times Cited Count:2 Percentile:9.06(Multidisciplinary Sciences)

Incoherent quasielastic neutron scattering (iQENS) is a fascinating technique for investigating the internal dynamics of protein. However, both low flux of neutron beam and absence of analytical procedure for extracting the internal dynamics from iQENS profile have been obstacles for studying it under physiological condition (in solution). Thanks to the recent development of neutron source, spectrometer and computational technique, they enable us to decouple internal dynamics, translational and rotational diffusions from the iQENS profile. The internal dynamics of two proteins: globular domain protein (GDP) and intrinsically disordered protein (IDP) in solution were studied. It was found that the average relaxation rate of IDP was larger than that of GDP. Through the detailed analyses on their internal dynamics, it was revealed that the fraction of mobile H atoms in IDP was much higher than that in GDP. Interestingly, the fraction of mobile H atoms was closely related to the fraction of H atoms on highly solvent exposed surfaces. The iQENS study presented that the internal dynamics were governed by the highly solvent exposed amino acid residues depending upon protein molecular architectures.

Journal Articles

Research on factor analysis for achieving denuclearization, 9; DPRK's denuclearization

Shimizu, Ryo; Kimura, Takashi; Tazaki, Makiko; Nakatani, Takayoshi; Tamai, Hiroshi; Suda, Kazunori

Dai-41-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 3 Pages, 2020/11

Efforts to denuclearize North Korea have been made by neighboring countries and related countries, but they have not abandoned North Korea's nuclear development. In this report, we will analyze the North Korean denuclearization negotiations that have been carried out so far, and report on the elements necessary for the realization of North Korea's denuclearization obtained from the past history.

Journal Articles

Research on factor analysis for achieving denuclearization, 6; Denuclearization of former republics of the Soviet Union

Kimura, Takashi; Tazaki, Makiko; Nakatani, Takayoshi; Shimizu, Ryo; Tamai, Hiroshi; Suda, Kazunori

Dai-41-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 3 Pages, 2020/11

Following the collapse of the Soviet Union in 1991, Ukraine, Kazakhstan, and Belarus (the former three Soviet Union countries) unintentionally deployed nuclear weapons within their territory. The former three Soviet Union countries achieved denuclearization by transferring the deployed warheads and the delivery system of the nuclear weapons to Russia for disposal. This report gives our analysis of the success factors for achieving denuclearization by investigating the efforts towards denuclearization of such countries, the relevant frameworks such as the Treaty on the Reduction of Strategic Arms, etc.

174 (Records 1-20 displayed on this page)