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Journal Articles

Electrochemical reaction mechanisms under various charge-discharge operating conditions for Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$ in a lithium-ion battery

Konishi, Hiroaki*; Hirano, Tatsumi*; Takamatsu, Daiko*; Gunji, Akira*; Feng, X.*; Furutsuki, Sho*; Okumura, Takafumi*; Terada, Shohei*; Tamura, Kazuhisa

Journal of Solid State Chemistry, 262, p.294 - 300, 2018/06

 Times Cited Count:6 Percentile:51.04(Chemistry, Inorganic & Nuclear)

The potential in each state of charge (SOC) during charging of Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$ is higher than that during discharging. To clarify the effect of chargedischarge operating conditions on the electrochemical reaction, Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$ was charged and discharged under various charge-discharge operating ranges, and OCP, crystal structure, and oxidation states of the ransition metals were evaluated by electrochemical measurement, XRD, and XAFS. These results indicate that OCP, lattice parameters, and oxidation states of the transition metals of Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$ in each SOC are not constant. The XRD results indicate that two phases, namely, LiNi$$_{0.33}$$Mn$$_{0.33}$$Co$$_{0.33}$$O$$_{2}$$-like and Li$$_{2}$$MnO$$_{3}$$-like, exist in Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$.

Journal Articles

Mechanisms responsible for two possible electrochemical reactions in Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$ used for lithium ion batteries

Konishi, Hiroaki*; Hirano, Tatsumi*; Takamatsu, Daiko*; Gunji, Akira*; Feng, X.*; Furutsuki, Sho*; Okumura, Takafumi*; Terada, Shohei*; Tamura, Kazuhisa

Journal of Solid State Chemistry, 258, p.225 - 231, 2018/02

 Times Cited Count:7 Percentile:57.15(Chemistry, Inorganic & Nuclear)

Li$$_{1.2}$$Ni$$_{0.13}$$Mn$$_{0.54}$$Co$$_{0.13}$$O$$_{2}$$ is known as one of the cathode electrode material for Li ion batteries and its structure during charge and discharge process was investigated using electrochemical method and X-ray diffraction. It was found that in the charge process the structure changes in the order of Li$$_{2}$$MnO$$_{3}$$, LiNi$$_{0.33}$$Mn$$_{0.33}$$Co$$_{0.33}$$O$$_{2}$$, and Li$$_{2}$$MnO$$_{3}$$. On the other hand, in the discharge process, the structure changes in the order of Li$$_{2}$$MnO$$_{3}$$ and LiNi$$_{0.33}$$Mn$$_{0.33}$$Co$$_{0.33}$$O$$_{2}$$.

Journal Articles

Current status of a new polarized neutron reflectometer at the intense pulsed neutron source of the Materials and Life Science Experimental Facility (MLF) of J-PARC

Takeda, Masayasu; Yamazaki, Dai; Soyama, Kazuhiko; Maruyama, Ryuji; Hayashida, Hirotoshi; Asaoka, Hidehito; Yamazaki, Tatsuya; Kubota, Masato; Aizawa, Kazuya; Arai, Masatoshi; et al.

Chinese Journal of Physics, 50(2), p.161 - 170, 2012/04

Journal Articles

COMPASS code development; Validation of multi-physics analysis using particle method for core disruptive accidents in sodium-cooled fast reactors

Koshizuka, Seiichi*; Morita, Koji*; Arima, Tatsumi*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; Okada, Hidetoshi*; Uehara, Yasushi*; et al.

Proceedings of 8th International Topical Meeting on Nuclear Thermal-Hydraulics, Operation and Safety (NUTHOS-8) (CD-ROM), 11 Pages, 2010/10

In this paper, FY2009 results of the COMPASS code development are reported. Validation calculations for melt freezing and blockage formation, eutectic reaction of metal fuel, duct wall failure (thermal-hydraulic analysis), fuel pin failure and disruption and duct wall failure (structural analysis) are shown. Phase diagram calculations, classical and first-principles molecular dynamics were used to investigate physical properties of eutectic reactions: metallic fuel/steel and control rod material/steel. Basic studies for the particle method and SIMMER code calculations supported the COMPASS code development. COMPASS is expected to clarify the basis of experimentally-obtained correlations used in SIMMER. Combination of SIMMER and COMPASS will be useful for safety assessment of CDAs as well as optimization of the core design.

Journal Articles

Detailed analyses of specific phenomena in core disruptive accidents of sodium-cooled fast reactors by the COMPASS code

Morita, Koji*; Zhang, S.*; Arima, Tatsumi*; Koshizuka, Seiichi*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Shirakawa, Noriyuki*; Inoue, Fusao*; Yugo, Hiroaki*; et al.

Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM), 9 Pages, 2010/05

A five-year research project has been initiated in 2005 to develop a code based on the MPS (Moving Particle Semi-implicit) method for detailed analysis of specific phenomena in core disruptive accidents (CDAs) of sodium-cooled fast reactors (SFRs). The code is named COMPASS (Computer Code with Moving Particle Semi-implicit for Reactor Safety Analysis). The specific phenomena include (1) fuel pin failure and disruption, (2) molten pool boiling, (3) melt freezing and blockage formation, (4) duct wall failure, (5) low-energy disruptive core motion, (6) debris-bed coolability, and (7) metal-fuel pin failure. Validation study of COMPASS is progressing for these key phenomena. In this paper, recent COMPASS results of detailed analyses for the several specific phenomena are summarized.

Journal Articles

Validation for multi-physics simulation of core disruptive accidents in sodium-cooled fast reactors by COMPASS code

Koshizuka, Seiichi*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; Okada, Hidetoshi*; et al.

Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM), 11 Pages, 2009/09

Dispersion and freezing of molten core material was calculated by the COMPASS code to compare with the experimental data of GEYSER. Molten core material flowed up with freezing on the pipe inner surface. As a molten pool behavior, CABRI-TPA2 experiment was analyzed, where a sphere of solid steel was surrounded by solid fuel. Power was injected to cause melting and boiling of the steel sphere. SCARABEE-BE+3 test was analyzed by COMPASS as a validation of failure of duct walls.

Journal Articles

COMPASS code development and validation; A Multi-physics analysis of core disruptive accidents in sodium-cooled fast reactors using particle method

Koshizuka, Seiichi*; Liu, J.*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; et al.

Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), 1 Pages, 2009/05

A computer code, named COMPASS, is developed for multi-physics analysis of core disruptive accidents of sodium-cooled fast reactors (SFRs). A meshless method, called MPS method, is employed since complex thermal-hydraulics and structural problems with various phase change processes have to be analyzed. Verification for separeted basic processes and validation for practical phenomena are carried out. COMPASS is also expected to investigate molten fuel discharge to avoid re-criticality in large size SFR cores. Both MOX and metal fuels are considered. Eutectic reactions between the metal fuel and the cladding material are investigated by phase diagram calculation, classical and first-principles molecular dynamics. Basic studies relevant to the numerical methods support the code development of COMPASS. Parallel processing is implemented by OpenMP to treat large-scale problems. A visualization tool is also prepared by using AVS.

Journal Articles

Magnetic structure analysis of magnetic multilayers using neutron reflectometry

Hirano, Tatsumi*; Takeda, Masayasu

Magune, 4(1), p.38 - 42, 2009/01

The characterization of a magnetic interface structure in magnetic multilayer is important for producing good magnetic devices because the device properties strongly depend on the structure. In this report we review a polarized neutron reflectometry to analyze the magnetic interface structure and also mention a future prospect of a neutron experiment.

Journal Articles

Code development for multi-physics and multi-scale analysis of core disruptive accidents in fast reactors using particle methods

Koshizuka, Seiichi*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Shirakawa, Noriyuki*; Naito, Masanori*; Okada, Hidetoshi*; et al.

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10

A computer code, named COMPASS, is being developed for various complex phenomena of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The COMPASS is designed to analyze multi-physics problems involving thermal hydraulics, structure and phase change, in a unified framework of the MPS (Moving Particle Semi-implicit) method. The project has been carried out by six organizations for five years from FY2005 to FY2009. In this paper, the outcomes of the project in FY2007 are presented. Three validation calculations were completed by following the validation plan: melt freezing and blockage formation, molten pool boiling, and duct wall failure. The COMPASS code development was supported by basic studies of the numerical method, material science for eutectic reaction of the metal fuel, and SIMMER-III analyses.

Journal Articles

Code development for core disruptive accidents in sodium-cooled fast reactors

Koshizuka, Seiichi*; Liu, J.*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; et al.

Proceedings of IAEA Topical Meeting on Advanced Safety Assessment Methods for Nuclear Reactors (CD-ROM), 9 Pages, 2007/10

A computer code, named COMPASS (Computer Code with Moving Particle Semi-implicit for Reactor Safety Analysis), is being developed for various complex phenomena of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). Theoretical studies are performed about a unified algorithm for compressible and incompressible flows, fluid flow with solid debris, and algorithm improvement for free surface flows. Code verification and validation procedures are established by exploiting the past experiences in those of SIMMER-III code. COMPASS will be used for separated phenomena in CDAs, while the whole core will be analyzed by SIMMER-III. COMPASS is expected to clarify the detailed process in duct wall failure and fuel discharge to avoid re-criticality during CDAs in large size SFRs.

Journal Articles

Multi-physics and multi-scale simulation for core disruptive accidents in fast breeder reactors

Koshizuka, Seiichi*; Liu, J.*; Morita, Koji*; Arima, Tatsumi*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Shirakawa, Noriyuki*; Hosoda, Seigo*; Araki, Kazuhiro*; et al.

Proceedings of 5th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-5), p.472 - 479, 2006/11

A 5-year research project started in FY2005 in the framework of Innovative Nuclear Research and Development Program funded by the Ministry of Education, Culture, Sports, Science and Technology in Japan. A computer code, named COMPASS (Computer Code with Moving Particle Semi-implicit for Reactor Safety Analysis), is being developed using the Moving Particle Semi-implicit (MPS) method for various complex phenomena of severe accidents in fast breeder reactors. Both MOX and metal fuels are considered. Eutectic reactions between the metal fuel and the cladding material are being investigated by molecular dynamics and molecular orbital methods. The molten metal flow with solidification was analyzed by MPS. The elastic analysis of a hexagonal wrapper tube was analyzed by the MPS method as well. The results were compared with an experiment and an calculation using an commercial code. Eutectic reactions were calculated by molecular dynamics and compared with the references. We found that the combination of the above numerical methods was useful for multi-physics and multi-scale phenomena of core disruptive accidents in fast breeder reactors.

Oral presentation

R&D of the next generation safety analysis methods for fast reactors with new computational science and technology, 8; Status of R&D in FY2006

Koshizuka, Seiichi*; Liu, J.*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; et al.

no journal, , 

A computer code is developed based on a particle method technology in order to simulate in detail various phenomana in core disruptive accidents in fast reactors. This report is a summary of progress during FY2006 in a five-year project of the code development.

Oral presentation

Outline design specification of a new polarized neutron reflectometer for the intense pulsed neutron source (JSNS) at J-PARC

Takeda, Masayasu; Yamazaki, Dai; Soyama, Kazuhiko; Hirano, Tatsumi*

no journal, , 

The X-ray and neutron reflectometries have now widely used for the study of buried interfaces in thin films and multilayers. Neutron is an ideal probe for the reflectometry because of its transparency for the most of materials, and its sensitivity of light elements and magnetic moments in the materials. An intense pulsed neutron source (JSNS) is now under construction at Materials and Life Science Facility (MLF) as a part of J-PARC (Japan Proton Accelerator Research Complex) in Tokai-mura, Ibaraki prefecture, Japan. JSNS will provide the world highest intensity pulsed neutron for promoting materials science and life science in the beginning of the next spring. We have sent a letter of intent which proposed to construct a polarized neutron reflectometer at MLF to the director of J-PARC, and a preliminary examination has been passed. The outline design specification of this new polarized neutron reflectometer will be presented.

Oral presentation

Outline design specification of a new polarized neutron reflectometer proposed for materials and life science facility at J-PARC

Takeda, Masayasu; Yamazaki, Dai; Soyama, Kazuhiko; Hirano, Tatsumi*

no journal, , 

The X-ray and neutron reflectometries have now widely used for the study of depth profiles of various thin films and multilayers. In addition, the technique gives information on in-plane structures of various surfaces and buried interfaces by analysis of off-specular reflection profiles. Such structural information in the vicinity of interfaces is often a clue to elucidate the origin of new phenomena appearing in artificial multilayers and to develop the high performance devises with the layered structure in which the interface plays an essential role in the function. We propose a polarized neutron reflectometer for JSNS to investigate the magnetic multilayers, following increasing interest in interfacial magnetism which has a close relation to the function of the magnetic recording devices. The outline design specification of this new polarized neutron reflectometer will be presented.

Oral presentation

Magnetic structure analysis of magnetic multilayer using neutron reflectometry

Hirano, Tatsumi*; Takeda, Masayasu

no journal, , 

The characterization of a magnetic interface structure in magnetic multilayer is important for producing good magnetic devices because the device properties strongly depend on the structure. In this report we review a polarized neutron reflectometry to analyze the magnetic interface structure and also mention a future prospect of a neutron experiment.

Oral presentation

The Concept of the polarized neutron reflectometer designed for J-PARC

Takeda, Masayasu; Yamazaki, Dai; Soyama, Kazuhiko; Hirano, Tatsumi*; Suzuki, Junichi; Aizawa, Kazuya; Suzuya, Kentaro; Arai, Masatoshi; Asaoka, Hidehito

no journal, , 

The interfacial magnetism in the magnetic multilayers is a key to achieve the high-performance magnetic devices. Polarized neutron reflectometry is a powerful tool to investigate such interfacial magnetism. We have a plan to install the polarized neutron reflectometer at Materials and Life Science Facility (MLF) in Japan Proton Accelerator Research Complex (J-PARC). We present the design concept and the expected performance of the polarized neutron reflectometer.

Oral presentation

Magnetic structural analysis of magnetic multilayers for read sensor heads by complementary use of polarized neutron and X-ray

Takeda, Masayasu; Yamazaki, Dai; Hirano, Tatsumi*

no journal, , 

The characterization of the magnetic interface structure in magnetic multilayers of a read sensor head is indispensable for producing the high-performance and high-reliability read sensor heads, because the device properties strongly depend on the structure. X-ray and neutron reflectometry is a powerful and nondestructive technique to investigate the internal layered structures. In this presentation, it is reported that several results of measurements of the magnetic multilayers for the read sensor heads using a conventional X-ray reflectometer in a laboratory and a new neutron reflectometer, SUIREN, installed at the C2-2 cold neutron beam port of the neutron guide hall in the research reactor, JRR-3, of Japan Atomic Energy Agency.

Oral presentation

J-PARC polarized neutron reflectometer

Yamazaki, Dai; Takeda, Masayasu; Soyama, Kazuhiko; Maruyama, Ryuji; Hirano, Tatsumi*

no journal, , 

We have started designing a polarized neutron reflectometer which dedicates to investigation on magnetic multilayers at MLF. In this contribution, design concept of the J-PARC polarized neutron reflectometer will be presented together with beam-line simulations and test results of the focusing devices.

Oral presentation

Polarized neutron reflectometer at J-PARC, 2

Yamazaki, Dai; Takeda, Masayasu; Maruyama, Ryuji; Soyama, Kazuhiko; Hirano, Tatsumi*; Suzuki, Junichi; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi

no journal, , 

no abstracts in English

Oral presentation

A New polarized neutron reflectometer at materials and life science facility of J-PARC

Takeda, Masayasu; Maruyama, Ryuji; Aizawa, Kazuya; Arai, Masatoshi; Kaneko, Koji; Nakatani, Takeshi; Shinohara, Takenao; Suzuki, Junichi; Suzuya, Kentaro; Takahashi, Nobuaki; et al.

no journal, , 

33 (Records 1-20 displayed on this page)