Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Se
Lee, C. H.*; Nishida, Atsuhiro*; Hasegawa, Takumi*; Nishiate, Hirotaka*; Kunioka, Haruno*; Kawamura, Seiko; Nakamura, Mitsutaka; Nakajima, Kenji; Mizuguchi, Yoshikazu*
Applied Physics Letters, 112(2), p.023903_1 - 023903_4, 2018/01
Times Cited Count：28 Percentile：77.9(Physics, Applied)Low energy phonons in LaOBiSSe are studied using inelastic neutron scattering. Dispersionless flat phonon branches that are mainly associated with a large vibration of Bi atoms are observed at a relatively low energy of 
= 6 - 6.7 meV. The phonon energy softens upon Se doping owing to its heavier atomic mass than S atom and the expansion of lattice constant. Simultaneously, the lattice thermal conductivity lowered upon Se doping as the same manner of the phonon softening. These suggest that despite the lack of an oversized cage in LaOBiSSe, rattling motions of Bi atoms can scatter phonon like rattling in cage compounds, contributing to enhance the thermoelectric property.
Matsuki, Takuya; Masui, Kenji; Sekine, Megumi; Tanigawa, Masafumi; Yasuda, Takeshi; Tsutagi, Koichi; Ishiyama, Koichi; Nishida, Naoki; Horigome, Kazushi; Mukai, Yasunobu; et al.
Proceedings of INMM 57th Annual Meeting (Internet), 9 Pages, 2016/07
The International Atomic Energy Agency (IAEA) has proposed in its long-term research and development (R&D) plan, development of a real-time measurement technology to monitor and verify nuclear material movement continuously as part of an advanced approach to effectively and efficiently conduct safeguards for reprocessing facilities. Since the Tokai Reprocessing Plant (TRP) has solutions containing both Pu and fission products (FP), a new detector development project to monitor Pu with FP is being carried out from 2015 to 2017. This project is mainly conducted in the High Active Liquid Waste Storage (HALWS) in the TRP. For the first step of this project, as the confirmation of composition of high active liquid waste (HALW) to evaluate neutron/
-ray emitted from solution in the selected HALW tank which has the most amount of Pu in HALW tanks at the TRP, we took HALW sample and conducted -ray spectrum measurement for HALW. As a study of detector setting location, to survey the available neutron/-ray (i.e. intensity) at the outside surface of the cell where HALW tank is located, we implemented continuous measurement by neutron/-ray detector. In this paper, we report three -ray peaks related with 
Pu and 
Pu measured in the composition research of HALW, which is needed to identify Pu amount by the new detector that we are developing and the result of radiation measurement on the surface of the cell.
Shibata, Takanori*; Nishida, Kenjiro*; Mochizuki, Shintaro*; Mattei, S.*; Lettry, J.*; Hatayama, Akiyoshi*; Ueno, Akira; Oguri, Hidetomo; Okoshi, Kiyonori; Ikegami, Kiyoshi*; et al.
Review of Scientific Instruments, 87(2), p.02B128_1 - 02B128_3, 2016/02
Times Cited Count：3 Percentile：16.49(Instruments & Instrumentation)A numerical model of plasma transport and electromagnetic field in the J-PARC RF ion source has been developed to understand relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. The magnetic field line with absolute magnetic flux density 30-120 Gauss results in the magnetization of electron which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.
Tobita, Toru; Nakagawa, Sho*; Takeuchi, Tomoaki; Suzuki, Masahide; Ishikawa, Norito; Chimi, Yasuhiro; Saito, Yuichi; Soneda, Naoki*; Nishida, Kenji*; Ishino, Shiori*; et al.
Journal of Nuclear Materials, 452(1-3), p.241 - 247, 2014/09
Times Cited Count：17 Percentile：76.64(Materials Science, Multidisciplinary)Three kinds of Fe-based model alloys, Fe-0.018 atomic percent (at.%) Cu, Fe-0.53at.%Cu, and Fe-1.06at.%Cu were irradiated with 2 MeV electrons up to the dose of 2
10
dpa at 250
C. After the irradiation, the increase in Vickers hardness and the decrease in electrical resistivity were observed. The increase in hardness by electron irradiation is proportional to the product of the Cu contents and the square root of the electron dose. The decrease in electrical resistivity is proportional to the product of the square of Cu contents and the electron dose. Cu clustering in the materials with electron irradiation and thermal aging was observed by means of the three dimensional atom probes (3D-AP). The change in Vickers hardness and electrical resistivity is well correlated with the volume fraction of Cu clusters.
Ueyama, Daichi*; Semboshi, Satoshi*; Saito, Yuichi; Ishikawa, Norito; Nishida, Kenji*; Soneda, Naoki*; Hori, Fuminobu*; Iwase, Akihiro*
Japanese Journal of Applied Physics, 53(5S1), p.05FC04_1 - 05FC04_5, 2014/05
Times Cited Count：9 Percentile：34.69(Physics, Applied)In our previous research, it was found that the hardness of Cu-Ti alloy increased by energetic heavy ion irradiation at room temperature. In the conference, we will show the result of electron beam irradiation on the hardness of Cu-Ti alloys. We used CuTi sheets with the dimension of 10 10 0.250 mm
. The specimens were irradiated at 473 K and 523 K with 2 MeV electrons. For comparison, we thermally aged some specimens at the same temperatures as that for the irradiation. The electron fluence of 8.0 10
/cm
corresponds to the processing time of about 10 h. As a result, the thermal aging for 10 h increases the hardness by 5 or less, which is much smaller than that by the irradiation (about 20). The hardness of the reverse side of irradiated surface is almost the same as that of the irradiated surface. The present result implies that energetic electron irradiation can be a useful tool for controlling the hardness of the "bulk" Cu-Ti alloy.
Mitsuda, Tomoaki*; Kobayashi, Ippei*; Kosugi, Shinya*; Fujita, Naoki*; Saito, Yuichi; Hori, Fuminobu*; Semboshi, Satoshi*; Kaneno, Yasuyuki*; Nishida, Kenji*; Soneda, Naoki*; et al.
Nuclear Instruments and Methods in Physics Research B, 272, p.49 - 52, 2012/02
Times Cited Count：9 Percentile：52.49(Instruments & Instrumentation)Mitsuda, Tomoaki*; Kobayashi, Ippei*; Kosugi, Shinya*; Fujita, Naoki*; Saito, Yuichi; Hori, Fuminobu*; Semboshi, Satoshi*; Kaneno, Yasuyuki*; Nishida, Kenji*; Soneda, Naoki*; et al.
Journal of Nuclear Materials, 408(2), p.201 - 204, 2011/01
Times Cited Count：13 Percentile：66.82(Materials Science, Multidisciplinary)
Ti)0
Yoneda, Yasuhiro; Saito, Hiroyuki; Yoshii, Kenji; Nishida, Takashi*; Hayakawa, Hironori*; Ikeda, Naoshi*
Key Engineering Materials, 421-422, p.30 - 33, 2010/00
Polycrystalline Bi(MgTi)O samples were prepared under high pressure. A mixed powder of Bi
O, TiO and MgO with a prescribed ratio was packed into platinum cell and was heated a cubic anvil-type apparatus at 6.5 GPa and 1000 
C. The obtained samples were characterized by powder X-ray diffraction measurements. Although some impurity peaks existed, the main peaks were perovskite peaks. The structure of Bi(MgTi)O is rhombohedral, as well as BiFeO. The D-E hysteresis loop was not saturated due to the impurities, but the possibility as ferroelectric can be expected enough.
from molten saltsAbe, Hideki*; Yoshii, Kenji; Nishida, Kenji*; Imai, Motoharu*; Kitazawa, Hideaki*
Journal of Physics and Chemistry of Solids, 66(2-4), p.406 - 409, 2005/04
Times Cited Count：7 Percentile：33.79(Chemistry, Multidisciplinary)An electroplating technique of the superconductive boride MgB onto graphite substrates is reported. Films of MgB with a thickness of tens micrometer were fabricated on the planar and curved surfaces of graphite substrates by means of electrolysis on a mixture of magnesium chloride, potassium chloride, sodium chloride, and magnesium borate fused at high temperatures in an Ar atmosphere. The electrical resistivity and magnetization measurements revealed that the electroplated MgB films undergo a superconducting transition with the critical temperature of 36 K.
from molten saltsAbe, Hideki*; Yoshii, Kenji; Nishida, Kenji*; Imai, Motoharu*; Kitazawa, Hideaki*
Journal of Physics and Chemistry of Solids, 66(1), p.406 - 409, 2005/01
no abstracts in English
films electroplated to stainless steel substratesAbe, Hideki*; Nishida, Kenji*; Imai, Motoharu*; Kitazawa, Hideaki*; Yoshii, Kenji
Applied Physics Letters, 85(25), p.6197 - 6199, 2004/12
Times Cited Count：15 Percentile：51.46(Physics, Applied)no abstracts in English
(M
,Si) (M=Sr and Ba, M=Al and Ga), ternary silicides with the AlB-type structureImai, Motoharu*; Nishida, Kenji*; Kimura, Takashi*; Kitazawa, Hideaki*; Abe, Hideki*; Kito, Hijiri*; Yoshii, Kenji
Physica C, 382(4), p.361 - 366, 2002/11
Times Cited Count：57 Percentile：88.53(Physics, Applied)no abstracts in English
Nishida, Kazuhiro; Kitamura, Kenji*; Yamada, Fumiaki
Saikuru Kiko Giho, (10), p.5 - 13, 2001/03
The results of the function test and the startup test of the Prototype Fast Breeder Reactor Monju were examined for the hypothetical analysis of the rapid withdrawal of the control rod assembly and to analyze pump seizure in the Primary Heat Transport System, in order to obtain accurate transition of the plant dynamics. These analyses confirmed that both of the accidents settle down without affecting the plant structure. During the withdrawal accident, reactor power reached 106%. During the pump seizure accident, the fuel cladding mid-wall temperature reached 702C. Both of these values are sufficiently below the safety margins for anomaly transients and accidents during operation and former analyses for design safety permission. The differences between these results and the former analyses for design safety permission have mostly been attributed to the characteristics of the control rods.
Ti)OYoneda, Yasuhiro; Nishida, Takashi*; Saito, Hiroyuki; Yoshii, Kenji
no journal, ,
The antiferroelectric crystal can become very useful ferroelectric by combining with other ferroelectric though is only by it a wonderful, electric characteristic. It was reported to synthesize Bi(MgTi) O by the high temperature high pressure synthesis by Khalyavin though it was one of bisumuth perovsukite, and the synthesis was difficult in the normal pressure. Bi(MgTi) O was collected in a method similar as for us and when the high temperature high pressure was synthesized, the sample that became rhombohedral structure a room temperature was able to be collected. When the P-E hysteresis loop of this sample was measured, the result of suggesting hysteresis strong dielectric feature. It was found that the rhombohedral structure is the metastable phase though it was stable phase in the high pressure.
Masaki, Yuji*; Miyauchi, Hironari*; Taguchi, Shigeo; Horigome, Kazushi; Ishibashi, Atsushi; Yamamoto, Masahiko; Masui, Kenji; Nishida, Naoki; Kuno, Takehiko; Surugaya, Naoki
no journal, ,
Reprocess the technology development center has longtime experience for the handling of the radiation and perform support aiming at the acquisition of the spot analysis technique about the radioactive nuclear material handling in response to a demand out of the mechanism.
Yoshii, Kenji; Tsuji, Takuya; Matsumura, Daiju; Nishida, Ginichi*; Inoue, Naoki*; Fukada, Yukimasa*; Yaita, Tsuyoshi
no journal, ,
We have investigated the magnetic properties of Bi-doped perovskite GdCrO, which was reported to be multiferroic below the magnetic transition temperature (170 K). For the low doping levels (about 5-10% Bi at the Gd site), single-phase samples could be prepared at 920C, a temperature which is much lower than the firing temperature of GdCrO (about 1300-1400C). This result is essentially the same as that of isostructural (Sm,Bi)CrO. Magnetic measurements showed that the magnetic properties were essentially identical to those of GdCrO. For example, the chromium spins show a ferrimagnetic transition at 170 K. Interestingly, these properties were entirely different from those of (Sm,Bi)CrO, which showed that the Bi doping led to a drastic lowering of magnetic transition temperature (by 140 K). We have also conducted X-ray absorption measurements to determine the crystallographic site of Bi. The results will be shown at the conference.
