Refine your search:     
Report No.
Search Results: Records 1-20 displayed on this page of 51

Presentation/Publication Type

Initialising ...


Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...


Initialising ...


Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

sparse-ir; Optimal compression and sparse sampling of many-body propagators

Wallerberger, M.*; Badr, S.*; Hoshino, Shintaro*; Huber, S.*; Kakizawa, Fumiya*; Koretsune, Takashi*; Nagai, Yuki; Nogaki, Kosuke*; Nomoto, Takuya*; Mori, Hitoshi*; et al.

Software X (Internet), 21, p.101266_1 - 101266_7, 2023/02

 Times Cited Count:3 Percentile:95.04(Computer Science, Software Engineering)

no abstracts in English

Journal Articles

Development of semiconductor switches for high-power crowbar circuits

Ono, Ayato; Takayanagi, Tomohiro; Fuwa, Yasuhiro; Shinozaki, Shinichi; Ueno, Tomoaki*; Horino, Koki*; Sugita, Moe; Yamamoto, Kazami; Kinsho, Michikazu; Ikoma, Naoya*; et al.

Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.395 - 399, 2023/01

At J-PARC, an ignitron is used for the crowbar device of the klystron power supply for high-frequency acceleration of a linear accelerator. Ignitron uses mercury, which is of limited use worldwide, and is expected to be discontinued in the future. Therefore, we designed a semiconductor crowbar switch for short-circuit protection of klystron using a MOS gate thyristor. We have manufactured an oval-type board module that realizes an operating output of 3 kV, 40 kA, and 50 $$mu$$s per board. For the control power supply to each board module assuming a high voltage of 120 kV, we adopted a self-power supply method that creates a control power supply with a high-voltage DCDC converter from the voltage shared and charged by each board module. It was possible to confirm the operating performance on a 1/2 scale (60 kV, 40 kA) against the voltage of the existing equipment (120 kV, 40 kA) by connecting twenty oval board modules in series. The output test result will be reported.

Journal Articles

Safe and rapid development of capillary electrophoresis for ultratrace uranyl ions in radioactive samples by way of fluorescent probe selection for actinide ions from a chemical library

Haraga, Tomoko; Ouchi, Kazuki; Sato, Yoshiyuki; Hoshino, Hitoshi*; Tanana, Rei*; Fujihara, Takashi*; Kurokawa, Hideki*; Shibukawa, Masami*; Ishimori, Kenichiro; Kameo, Yutaka; et al.

Analytica Chimica Acta, 1032, p.188 - 196, 2018/11

 Times Cited Count:12 Percentile:51.31(Chemistry, Analytical)

The development of safe, rapid and highly sensitive analytical methods for radioactive samples, especially actinide (An) ions, represents an important challenge. Here we propose a methodology for selecting appropriate emissive probes for An ions with very low consumption and emission of radioactivity by capillary electrophoresis-laser-induced fluorescence detection (CE-LIF), using a small chemical library of probes with eight different chelating moieties. It was found that the emissive probe, which possesses the tetradentate chelating moiety, was suitable for detecting uranyl ions. The detection limit for the uranyl-probe complex using CE-LIF combined with dynamic ternary complexation and on-capillary concentration techniques was determined to be 0.7 ppt. This method was successfully applied to real radioactive liquid samples collected from nuclear facilities.

Journal Articles

Retreat from stress; Rattling in a planar coordination

Suekuni, Koichiro*; Lee, C. H.*; Tanaka, Hiromi*; Nishibori, Eiji*; Nakamura, Atsushi*; Kasai, Hidetaka*; Mori, Hitoshi*; Usui, Hidetomo*; Ochi, Masayuki*; Hasegawa, Takumi*; et al.

Advanced Materials, 30(13), p.1706230_1 - 1706230_6, 2018/03

 Times Cited Count:43 Percentile:88.96(Chemistry, Multidisciplinary)

Thermoelectric materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. In this paper, we studied the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)$$_{12}$$(Sb,As)$$_{4}$$S$$_{13}$$. The results revealed that the Cu atoms in a planar coordination are rattling, which effectively scatter phonons. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination.

Journal Articles

Effect of topsoil removal and selective countermeasures on radiocesium accumulation in rice plants in Fukushima paddy field

Yang, B.*; Onda, Yuichi*; Omori, Yoshihiro*; Sekimoto, Hitoshi*; Fujiwara, Toru*; Wakiyama, Yoshifumi*; Yoshimura, Kazuya; Takahashi, Junko*; Sun, X.*

Science of the Total Environment, 603-604, p.49 - 56, 2017/12

 Times Cited Count:2 Percentile:7.67(Environmental Sciences)

Journal Articles

Numerical analysis of turbulent flow in a rectangular duct containing straight cylinder placed near a bottom wall

Sugiyama, Hitoshi*; Otemori, Toshiki*; Kato, Naoto*; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro

Jidosha Gijutsukai Gakujutsu Koenkai Zensatsushu, (147-14), p.25 - 30, 2014/10

Numerical analysis has been performed for three-dimensional developing turbulent flow in a rectangular duct containing straight cylinder placed near a bottom wall. In this kind of turbulent flow, it has been pointed out as a characteristic features that anisotropic turbulence generates the secondary flow of the second kind and pulsation flow is measured in narrow gap region located between cylinder and bottom wall. Comparisons with the experimental results suggest that the present method is able to predict velocity profiles correctly and reproduce both the secondary flow of the second kind and the generation of pulsation flow near the narrow region between cylinder and bottom wall.

Journal Articles

Application of capillary electrophoresis with laser-induced fluorescence detection for the determination of trace neodymium in spent nuclear fuel using complexation with an emissive macrocyclic polyaminocarboxylate probe

Haraga, Tomoko; Saito, Shingo*; Sato, Yoshiyuki; Asai, Shiho; Hanzawa, Yukiko; Hoshino, Hitoshi*; Shibukawa, Masami*; Ishimori, Kenichiro; Takahashi, Kuniaki

Analytical Sciences, 30(7), p.773 - 776, 2014/07

 Times Cited Count:6 Percentile:22.96(Chemistry, Analytical)

A simple and rapid method with low radiation exposure risk was developed for the determination of neodymium in spent nuclear fuel by CE with LIF detection using a fluorescent ligand having a macrocyclic hexadentate polyaminocarboxylate structure. The concentration of Nd(III) in a spent nuclear fuel sample was determined with no interference from various matrix elements, including lanthanides and uranium (at a 200-fold excess), with 92 $$pm$$ 3% recovery. This is due to method's high resolution based on establishing a ternary complex equilibrium during migration in which the hydroxyl ion plays an auxiliary role.

Journal Articles

Role of cerium oxide in the enhancement of activity for the oxygen reduction reaction at Pt-CeO$$_{x}$$ nanocomposite electrocatalyst; An in situ electrochemical X-ray absorption fine structure study

Masuda, Takuya*; Fukumitsu, Hitoshi*; Fugane, Keisuke*; Togasaki, Hirotaka*; Matsumura, Daiju; Tamura, Kazuhisa; Nishihata, Yasuo; Yoshikawa, Hideki*; Kobayashi, Keisuke*; Mori, Toshiyuki*; et al.

Journal of Physical Chemistry C, 116(18), p.10098 - 10102, 2012/05

 Times Cited Count:115 Percentile:94.05(Chemistry, Physical)

In situ electrochemical X-ray absorption fine structure (XAFS) measurements were performed at the Pt L$$_{3}$$ and Ce L$$_{3}$$ edges of the Pt-CeO$$_{x}$$/C catalyst, which was prepared by a combined process of precipitation and coimpregnation methods, as well as at the Pt L$$_{3}$$ edge of the conventional Pt/C catalyst in oxygen-saturated H$$_{2}$$SO$$_{4}$$ solution to clarify the role of CeO$$_{x}$$ in the reduction of the overpotential for the oxygen reduction reaction (ORR) at the Pt-CeO$$_{x}$$ nanocomposite compared with the conventional Pt/C catalyst. XAFS measurements clearly show that the enhancement of ORR activity is attributed to the inhibition of Pt oxide formation by the CeO$$_{x}$$ layer, of which Ce$$^{3+}$$ was oxidized to Ce$$^{4+}$$ instead of Pt at the Pt oxide formation potential.

Journal Articles

Electronic structure of heavy fermion uranium compounds studied by core-level photoelectron spectroscopy

Fujimori, Shinichi; Okochi, Takuo*; Kawasaki, Ikuto; Yasui, Akira; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 81(1), p.014703_1 - 014703_9, 2012/01

 Times Cited Count:37 Percentile:82.92(Physics, Multidisciplinary)

High-energy-resolution core-level and valence-band photoelectron spectroscopic studies were performed for the heavy Fermion uranium compounds UGe$$_2$$, UCoGe, URhGe, URu$$_2$$Si$$_2$$, UNi$$_2$$Al$$_3$$, UPd$$_2$$Al$$_3$$, and UPt$$_3$$ as well as typical localized and itinerant uranium compounds to understand the relationship between the uranium valence state and their core-level spectral line shapes. The core-level spectra of UGe$$_2$$, UCoGe, URhGe, URu$$_2$$Si$$_2$$, and UNi$$_2$$Al$$_3$$ are rather similar to those of itinerant compounds, suggesting that U 5$$f$$ electrons in these compounds are well hybridized with ligand states. On the other hand, the core-level spectra of UPd$$_2$$Al$$_3$$ and UPt$$_3$$ show considerably different spectral line shapes from those of the itinerant compounds, suggesting that U 5$$f$$ electrons in UPd$$_2$$Al$$_3$$ and UPt$$_3$$ are less hybridized with ligand states, leading to the correlated nature of U 5$$f$$ electrons in these compounds.

Journal Articles

Conduction-band electronic states of YbInCu$$_4$$ studied by photoemission and soft X-ray absorption spectroscopies

Utsumi, Yuki*; Sato, Hitoshi*; Kurihara, Hidenao*; Maso, Hiroyuki*; Hiraoka, Koichi*; Kojima, Kenichi*; Tobimatsu, Komei*; Okochi, Takuo*; Fujimori, Shinichi; Takeda, Yukiharu; et al.

Physical Review B, 84(11), p.115143_1 - 115143_7, 2011/09

 Times Cited Count:9 Percentile:40.24(Materials Science, Multidisciplinary)

We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu$$_4$$ by means of temperature-dependent hard X-ray photoemission spectroscopy (HX-PES), soft X-ray absorption spectroscopy (XAS), and soft X-ray photoemission spectroscopy (SX-PES) of the valence band. We have described the valence transition in YbInCu$$_4$$ in terms of the charge transfer from the CB to Yb 4$$f$$ states.

JAEA Reports

Study on potential impacts of natural phenomena on a HLW geological disposal system

Kawamura, Makoto; Makino, Hitoshi; Sasao, Eiji; Niizato, Tadafumi; Yasue, Kenichi; Asamori, Koichi; Umeda, Koji; Ishimaru, Tsuneari; Osawa, Hideaki; Ebashi, Takeshi; et al.

JAEA-Research 2010-027, 85 Pages, 2010/09


Japan Atomic Energy Agency (JAEA) have developed a formal evaluation method to assess the potential impacts of natural phenomena (earthquakes and faulting; volcanism; uplift, subsidence, denudation and sedimentation; climatic and sea-level changes) on a high level radioactive waste (HLW) disposal system for the purpose of maintenance of evaluation method for potential impacts of natural phenomena within more realistic view. In this report, we developed a framework as a part of the total system performance assessment for two purposes: the first one is quantification of relationship of characteristic of natural phenomena between geological environmental conditions (T-H-M-C-G), and the other one is quantification of relationship of T-H-M-C-G condition between parameters of performance assessment. We tried to apply the framework to all natural phenomena to confirm the effectiveness of the framework. On the other hand, we applied an argument-diagram that was developed one of the methods of the knowledge management to elicit future tasks. As a result, to apply the framework, we could show that information integration could carry out efficiently, and information integration was attained by the common framework by combining information on geohistory and existing information of natural phenomena and geological environmental conditions as modern-analogue. We could show that suitable scenarios might be chosen by information integration. Furthermore, we were able to elicit future tasks to this study by applying the argument-diagram.

Journal Articles

Antiferromagnetic interaction between paramagnetic Co ions in the diluted magnetic semiconductor Zn$$_{1-x}$$Co$$_x$$O

Kobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Osafune, Yoshitaka*; Fujimori, Atsushi*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke*; Saeki, Hiromasa*; et al.

Physical Review B, 81(7), p.075204_1 - 075204_7, 2010/02


 Times Cited Count:19 Percentile:62.78(Materials Science, Multidisciplinary)

Journal Articles

Experimental observation of bulk band dispersions in the oxide semiconductor ZnO using soft X-ray angle-resolved photoemission spectroscopy

Kobayashi, Masaki*; Song, G.-S.*; Kataoka, Takashi*; Sakamoto, Yuta*; Fujimori, Atsushi; Okochi, Takuo*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi; et al.

Journal of Applied Physics, 105(12), p.122403_1 - 122403_4, 2009/06


 Times Cited Count:11 Percentile:43.1(Physics, Applied)

Journal Articles

Design of neutron beamline for fundamental physics at J-PARC BL05

Mishima, Kenji*; Ino, Takashi*; Sakai, Kenji; Shinohara, Takenao; Hirota, Katsuya*; Ikeda, Kazuaki*; Sato, Hiromi*; Otake, Yoshie*; Omori, Hitoshi*; Muto, Suguru*; et al.

Nuclear Instruments and Methods in Physics Research A, 600, p.342 - 345, 2009/02

 Times Cited Count:27 Percentile:86.01(Instruments & Instrumentation)

A new beamline for a fundamental physics experiment is under construction at BL05 port in the Materials and Life Science Facility (MLF) at Japan Proton Accelerator Research Complex (J-PARC), this beamline is designed using novel techniques of neutron optics and it is termed "Neutron Optics and Physics". The beam from the moderator is deflected by multi-channel supermirrors and split into three branches for individual experiments. In this study, we have optimized the design of the beam optics and shields using the Monte Carlo simulation package PHITS. The neutron fluxes of beams are expected to be $$9.2 times 10^5/$$cm$$^2/mu$$str$$/$$s$$/$$MW, $$1.2 times 10^9/$$cm$$^2/$$s$$/$$MW, $$4.0 times 10^8/$$cm$$^2/$$s$$/$$MW, with polarization of 99.8%.

JAEA Reports

Study on evaluation method of potential impact of natural phenomena on a HLW disposal system

Kawamura, Makoto; Oi, Takao; Niizato, Tadafumi; Yasue, Kenichi; Tokiwa, Tetsuya; Niwa, Masakazu; Shimada, Koji; Kurosawa, Hideki; Asamori, Koichi; Kawachi, Susumu; et al.

JAEA-Research 2008-018, 47 Pages, 2008/03


In this report, we sophisticated the framework as a part of the total system performance assessment for two purposes: the first one is quantification of relationship of characteristic of natural phenomena between geological environmental conditions (THMCG), and the other one is quantification of relationship of THMCG condition between parameters of performance assessment. On the other hand, we applied the sophisticated framework to all natural phenomena. As a result, to apply the sophisticated framework, we could show that information integration could carry out efficiently. Moreover, we have checked that the framework was applicable to all phenomena. Furthermore, we could show that suitable scenarios might be chosen by information integration.

Journal Articles

Photoemission and X-ray absorption studies of valence states in (Ni,Zn,Fe,Ti)$$_3$$O$$_4$$ thin films exhibiting photoinduced magnetization

Kobayashi, Masaki*; Oki, Yasuhiro*; Takizawa, Masaru*; Song, G. S.*; Fujimori, Atsushi; Takeda, Yukiharu; Terai, Kota*; Okane, Tetsuo; Fujimori, Shinichi; Saito, Yuji; et al.

Applied Physics Letters, 92(8), p.082502_1 - 082502_3, 2008/02

 Times Cited Count:12 Percentile:45.27(Physics, Applied)

Journal Articles

Construction of the vertical test system for the superconducting cavity in KEK-STF

Yamamoto, Yasuchika*; Hayano, Hitoshi*; Kako, Eiji*; Noguchi, Shuichi*; Sato, Masato*; Shishido, Toshio*; Umemori, Kensei*; Watanabe, Ken*; Sakai, Hiroshi*; Shinoe, Kenji*; et al.

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.888 - 891, 2008/00

In KEK, the new Superconducting RF Test Facility(STF) is being constructed, including the electro-polish system (EP), the high pressure rinsing system (HPR), the clean-room, the refrigerator system, the high power RF source system, and the vertical test system. The cavity is generally measured in the vertical cryostat for the performance test. The new vertical test facility was constructed since the last year, and completed at the beginning of March. The first test was done for the total system check at the beginning of July.

Journal Articles

Soft X-ray magnetic circular dichroism study of weakly ferromagnetic Zn$$_{1-x}$$V$$_{x}$$O thin film

Ishida, Yukiaki*; Hwang, J. I.*; Kobayashi, Masaki*; Takeda, Yukiharu; Mamiya, Kazutoshi*; Okamoto, Jun*; Fujimori, Shinichi; Okane, Tetsuo; Terai, Kota*; Saito, Yuji; et al.

Applied Physics Letters, 90(2), p.022510_1 - 022510_3, 2007/01

 Times Cited Count:23 Percentile:64.91(Physics, Applied)

no abstracts in English

Journal Articles

Characterization of magnetic components in the diluted magnetic semiconductor Zn$$_{1-x}$$Co$$_x$$O by X-ray magnetic circular dichroism

Kobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Mizokawa, Takashi*; Fujimori, Atsushi*; Mamiya, Kazutoshi*; Okamoto, Jun*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; et al.

Physical Review B, 72(20), p.201201_1 - 201201_4, 2005/11

 Times Cited Count:139 Percentile:96.2(Materials Science, Multidisciplinary)

no abstracts in English

JAEA Reports

The Support Activities of JNC against the JCO Criticality Accident

Kanamori, Masashi; Kawata, Tomio; Hitoshi, Watanabe,; Tobita, Yoshiharu; Sugiyama, Toshihide; Miyabe, Kenjiro; Kobayashi, Hirohide

JNC TN8450 2003-009, 506 Pages, 2004/03


This paper describes all the activities that were executed by JNC related to JCO criticality accident on September 30,1999. During the JCO accident, the activities of radiation monitoring, environmental monitoring, criticality termination operation, computer simulation of criticality accident, whole body exposure measurements by WBC about 24-Na, back up of local government like consultation of residents near by were performed by JNC. After the accident Japanese government and Nuclear Safety Commission establishes the investigation committee of JCO accident. JNC has also back up this activity. For example, investigation of the causes, accident scenario, estimation of the doses of the workers and personnel for deserter, counter measure operation. This paper summarizes all the important activity executed by JNC in the meantime.

51 (Records 1-20 displayed on this page)