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Journal Articles

Design and actual performance of J-PARC 3 GeV rapid cycling synchrotron for high-intensity operation

Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.

Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09

 Times Cited Count:3 Percentile:80.29(Nuclear Science & Technology)

In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.

Journal Articles

Alternation of magnetic anisotropy accompanied by metal-insulator transition in strained ultrathin manganite heterostructures

Kobayashi, Masaki*; Anh, L. D.*; Suzuki, Masahiro*; Kaneta-Takada, Shingo*; Takeda, Yukiharu; Fujimori, Shinichi; Shibata, Goro*; Tanaka, Arata*; Tanaka, Masaaki*; Oya, Shinobu*; et al.

Physical Review Applied (Internet), 15(6), p.064019_1 - 064019_10, 2021/06

 Times Cited Count:0 Percentile:28.82(Physics, Applied)

Journal Articles

Lanthanide intra-series separation by a 1,10-phenanthroline derivative; Counterion effect

Simonnet, M.; Suzuki, Shinichi; Miyazaki, Yuji*; Kobayashi, Toru; Yokoyama, Keiichi; Yaita, Tsuyoshi

Solvent Extraction and Ion Exchange, 38(4), p.430 - 440, 2020/00

 Times Cited Count:15 Percentile:70.69(Chemistry, Multidisciplinary)

Journal Articles

Evaluation of electronic state of Cs-adsorbed clay minerals by NEXAFS analysis using DFT calculations

Suzuki, Chikashi; Yaita, Tsuyoshi; Suzuki, Shinichi; Pacold, J.*; Altman, A. B.*; Minasian, S. G.*; Tyliszczak, T.*; Shuk, D. K.*; Yoshida, Hiroyuki; Osaka, Masahiko

Journal of Physics and Chemistry of Solids, 127, p.169 - 177, 2019/04

 Times Cited Count:5 Percentile:22.33(Chemistry, Multidisciplinary)

A combined method of NEXAFS measurement and DFT-calculation was employed for Cs evaluation in clay minerals. The Cs M$$_{4,5}$$ NEXAFS spectra of Cs halides were analyzed using the DFT-calculations, and were well reproduced by incorporating the core-hole strength. The Cs M$$_{4,5}$$ NEXAFS spectrum of clay minerals was well-reproduced by the DFT-calculations including the major transitions and tail structures with the established method. The further evaluation of this spectrum by charge density suggests that these major transitions and the tail structures likely reflect bonding states and local environments around the Cs atoms. Comparison of electronic states of Cs in the clay mineral with those in the Cs halides by DFT-calculations has shown that the interaction between Cs and the nearest-neighbor atom is largest in the clay mineral, because the energy level of Cs-5s and 5p is closer to that of O-2s and 2p than the s and p orbitals of other alkali metal and alkali earth metal elements.

Journal Articles

Electrochemical Cs removal and crystal formation from Fukushima weathered biotite in molten NaCl-CaCl$$_{2}$$

Honda, Mitsunori; Goto, Takuya*; Sakanaka, Yoshihide*; Yaita, Tsuyoshi; Suzuki, Shinichi*

AIMS Electronics and Electrical Engineering (Internet), 3(2), p.102 - 110, 2019/03

The possibility of removal and controlling crystal formation from weathered biotite (WB) in clay minerals were investigated using molten salt electrochemistry (EC) in molten NaCl-CaCl$$_{2}$$ under an electrochemical reductive reaction. Cyclic Voltammogram (CV) measurements were performed in the range of +0.5 V to -2.2 V. Several peaks were confirmed in the CV spectra. The peak at -1.4 V represents a reduction reaction of Fe in WB, so we conducted an experiment at -1.4 V for 2 h to reduce Iron (Fe). The Cs removal rate after EC treatment was determined by X-ray fluorescence analysis, and almost 100% Cs removal was confirmed. To understand the effect of the reductive reaction, we performed X-ray Adsorption Fine Structure (XAFS) analysis. Before EC treatment, the Fe in WB was present as a mixture of Fe$$^{3+}$$ and Fe$$^{2+}$$. After EC treatment, the presence of Fe$$^{2+}$$ was confirmed by XAFS analysis. Based on this finding, EC treatment is effective for reducing Fe in WB. This result indicated that Fe$$_{2}$$O$$_{3}$$ formation was suppressed, and the reduction reaction was effective for controlling crystal formation.

Journal Articles

Complexation properties and structural character of lanthanides complexes of $$O,N$$-hetero donor ligand BIZA

Kobayashi, Toru; Akutsu, Kazuhiro*; Nakase, Masahiko*; Suzuki, Shinichi; Shiwaku, Hideaki; Yaita, Tsuyoshi

Separation Science and Technology, 54(13), p.2077 - 2083, 2019/02

 Times Cited Count:5 Percentile:22.87(Chemistry, Multidisciplinary)

Development of separation reagent, which can efficiently separate lanthanides, is of increasing importance because it concerns establishment of purification and recycle techniques rare-earth elements. In our research group, several hetero donor type ligands, which have both oxygen and heterocyclic nitrogen atoms as donor atoms, were developed and revealed that this type of ligands show the selective complexation with specific lanthanide. In this paper, we will discuss the lanthaides complexation properties of the hetero donor type ligand containing benzimidazole group as nitrogen donor ($$N$$-methyl-$$N$$-phenyl-2-(1$$H$$-benzimidazol-2-yl)-pyridine-6-carboxamide) based on structural investigation by crystallography.

Journal Articles

Quantitative analysis of Cs extraction by some dialkoxycalix[4]arene-crown-6 extractants

Simonnet, M.; Miyazaki, Yuji*; Suzuki, Shinichi; Yaita, Tsuyoshi

Solvent Extraction and Ion Exchange, 37(1), p.81 - 95, 2019/00

 Times Cited Count:4 Percentile:18.03(Chemistry, Multidisciplinary)

Journal Articles

Cesium liquid-liquid extraction by calix-crown ethers; Solvent effect

Simonnet, M.; Miyazaki, Yuji; Suzuki, Shinichi; Yaita, Tsuyoshi

Progress in Nuclear Science and Technology (Internet), 5, p.66 - 69, 2018/11

Journal Articles

Absorbent property of fullerene for cesium isotope separation investigated using X-ray photoelectron spectroscopy

Sekiguchi, Tetsuhiro; Yokoyama, Keiichi; Uozumi, Yuki*; Yano, Masahiro; Asaoka, Hidehito; Suzuki, Shinichi; Yaita, Tsuyoshi

Progress in Nuclear Science and Technology (Internet), 5, p.161 - 164, 2018/11

For nuclear transmutation of cesium-135 ($$^{135}$$Cs), which is long-lived fission product, we are developing selective absorbent which takes only Cs atom in, but does not CsI. In this study, absorbing property of Cs atom onto the surface of fullerene (C$$_{60}$$) film has been investigated using synchrotron-based angle-dependent X-ray photoelectron spectroscopy (XPS). The results were compared with those of CsI. It was found that Cs penetrates into C$$_{60}$$ deep bulk. In contrast, CsI deposits on shallow surface. Furthermore, XPS spectra were measured as a function of Ar$$^{+}$$-sputtering time in order to know Cs concentration profiles in deep region. Results showed that Cs penetrates into deep region of several hundreds ${AA}$.

Journal Articles

Lanthanides complexation properties of O, N-hetero donor ligand PTA

Kobayashi, Toru; Suzuki, Shinichi; Shiwaku, Hideaki; Yaita, Tsuyoshi

Progress in Nuclear Science and Technology (Internet), 5, p.74 - 77, 2018/11

Development of extractant, which can efficiently separate actinides, is of increasing importance because it concerns establishment and simplification of separation techniques in nuclear fuel cycle and decontamination of radioactive wastes. In this study, the complexation properties of N-alkyl-N-phenyl-1,10-phenanthroline-2-carboxamide (PTA) with trivalent lanthanides (Ln$$^{3+}$$) were investigated based on structural analysis by using X-ray crystallography and extended X-ray absorption fine structure (EXAFS) methods. As a result, it is revealed that two PTA molecules coordinate with Ln$$^{3+}$$ as tridentate ligand via two nitrogen in phenanthroline moiety and one oxygen in amide moiety in both crystal and solution states. The slight difference in coordination bond distances are observed between Eu$$^{3+}$$ and Nd$$^{3+}$$ complexes, this difference corresponds to the difference in ionic radius between Nd$$^{3+}$$ and Eu$$^{3+}$$. This result indicates slight difference in ionic radii of Ln$$^{3+}$$ hardly affects coordination properties of PTA.

Journal Articles

Measurement of water-steam flow behavior and pressure distribution in venturi scrubber

Uesawa, Shinichiro; Horiguchi, Naoki; Suzuki, Takayuki*; Shibata, Mitsuhiko; Yoshida, Hiroyuki

Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 11 Pages, 2018/10

Journal Articles

Development of simultaneous evaluation method of bubble behavior and electric field distribution around WMS by using TPFIT and EMSolution

Uesawa, Shinichiro; Suzuki, Takayuki*; Yoshida, Hiroyuki

Konsoryu Shimpojiumu 2018 Koen Rombunshu (Internet), 2 Pages, 2018/08

no abstracts in English

Journal Articles

Proposed cesium-free mineralization method for soil decontamination; Demonstration of cesium removal from weathered biotite

Honda, Mitsunori; Shimoyama, Iwao; Kogure, Toshihiro*; Baba, Yuji; Suzuki, Shinichi; Yaita, Tsuyoshi

ACS Omega (Internet), 2(12), p.8678 - 8681, 2017/12

 Times Cited Count:6 Percentile:26.76(Chemistry, Multidisciplinary)

Journal Articles

Reduction and resource recycling of high-level radioactive wastes through nuclear transmutation; Isolation techniques of Pd, Zr, Se and Cs in simulated high level radioactive waste using solvent extraction

Sasaki, Yuji; Morita, Keisuke; Ito, Keisuke; Suzuki, Shinichi; Shiwaku, Hideaki; Takahashi, Yuya*; Kaneko, Masaaki*; Omori, Takashi*; Asano, Kazuhito*

Proceedings of International Nuclear Fuel Cycle Conference (GLOBAL 2017) (USB Flash Drive), 4 Pages, 2017/09

no abstracts in English

Journal Articles

A Chemiluminescence sensor with signal amplification based on a self-immolative reaction for the detection of fluoride ion at low concentrations

Hisamatsu, Shugo; Suzuki, Shinichi; Komoto, Shigeo*; Kishikawa, Keiki*; Yamamoto, Yusuke*; Motokawa, Ryuhei; Yaita, Tsuyoshi

Tetrahedron, 73(27-28), p.3993 - 3998, 2017/07

 Times Cited Count:15 Percentile:58.19(Chemistry, Organic)

Journal Articles

Extraction and separation of Se, Zr, Pd, and Cs including long-lived radionuclides

Sasaki, Yuji; Morita, Keisuke; Suzuki, Shinichi; Shiwaku, Hideaki; Ito, Keisuke; Takahashi, Yuya*; Kaneko, Masaaki*

Solvent Extraction Research and Development, Japan, 24(2), p.113 - 122, 2017/06

The solvent extraction of Se, Zr, Pd, and Cs from nitric acid into 1-octanol (OC) and dodecane has been performed. These elements include long-lived radionuclides in spent nuclear fuels, so a simple separation method is indispensable for the development of the treatment of high-level liquid radioactive waste. It was found that Se can be extracted using phenylenediamine, Zr can be extracted using tetraoctyl diglycolamide and di-2-ethylhexyl phosphoric acid, and Pd can be extracted using (methylimino)bis(dioctylacetamide) and hexaoctylnitrilotriacetamide. These elements can be recovered in over 90% yield by these extractants from nitric acid into OC. A distribution ratio of Cs of greater than 1 can be obtained using di-t-butyldibenzo-18-crown-6. It is clear that 90% recovery of Cs can be achieved using an extraction solvent with ten times the volume of the aqueous phase.

Journal Articles

Development of cesium-free mineralization for decontamination and reuse of radioactive contaminated soil in Fukushima

Shimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Hirao, Norie*; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi

Photon Factory News, 35(1), p.17 - 22, 2017/05

We introduce Cs-free mineralization (CFM) for Cs removal and reuse of radioactive-contaminated soil in Fukushima and report recent work conducted in the BL27A beamline in Photon Factory. In this work, we investigated compositional and structural changes of Cs-sorbed weathered biotite (WB) before and after heating treatment with addition of NaCl-CaCl$$_{2}$$ salts under low-pressure condition, to study Cs desorption mechanism from clay minerals. X-ray fluorescence spectroscopy clarified that almost all Cs and K were removed with the salts at 700 $$^{circ}$$C. On the other hand, Ca increased with heating temperature. X-ray diffraction and transmission electron microscopy analysis clarified that phase transitions from WB to some Ca-rich silicate minerals, e.g., augite, were caused by the heating treatment with the salt. Based on these results, CFM is proposed for Cs removal utilizing the mechanism in which large monovalent cations are discharged with accompanying the phase transition. We also discuss the role of Cl in this reaction showing chemical bonding change of Cl observed using X-ray absorption spectroscopy in the early stage of the chemical reaction.

Journal Articles

Mechanism of Cs removal from Fukushima weathered biotite by heat treatment with a NaCl-CaCl$$_{2}$$ mixed salt

Honda, Mitsunori; Okamoto, Yoshihiro; Shimoyama, Iwao; Shiwaku, Hideaki; Suzuki, Shinichi; Yaita, Tsuyoshi

ACS Omega (Internet), 2(2), p.721 - 727, 2017/02

 Times Cited Count:18 Percentile:55.6(Chemistry, Multidisciplinary)

Journal Articles

Origin of robust nanoscale ferromagnetism in Fe-doped Ge revealed by angle-resolved photoemission spectroscopy and first-principles calculation

Sakamoto, Shoya*; Wakabayashi, Yuki*; Takeda, Yukiharu; Fujimori, Shinichi; Suzuki, Hakuto*; Ban, Yoshisuke*; Yamagami, Hiroshi; Tanaka, Masaaki*; Oya, Shinobu*; Fujimori, Atsushi*

Physical Review B, 95(7), p.075203_1 - 075203_5, 2017/02

 Times Cited Count:9 Percentile:43.06(Materials Science, Multidisciplinary)

Journal Articles

Development of a control system at a 3 MeV linac in J-PARC

Sawabe, Yuki*; Ishiyama, Tatsuya; Takahashi, Daisuke; Kato, Yuko; Suzuki, Takahiro*; Hirano, Koichiro; Takei, Hayanori; Meigo, Shinichiro; Kikuzawa, Nobuhiro; Hayashi, Naoki

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.647 - 651, 2016/11

In the J-PARC, a 3 MeV linac has been developed for the tests of beam scraper irradiation and charge exchange by high-power laser. To accomplish tests efficiently and safely, the control system for 3 MeV was designed and developed, and this system consists of four subsystems, personal protection system, machine protection system, timing system, and remote control system using the EPICS. In this paper, the details of control system for a 3 MeV linac are presented.

371 (Records 1-20 displayed on this page)