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F from 
O
?Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count：14 Percentile：74.18(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree (
) knockout reaction. The sum of spectroscopic factors of 
orbital is found to be 1.0 
0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 
35% O
, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the 
proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Kobata, Masaaki; Okane, Tetsuo; Kobayashi, Keisuke*
Bunko Kenkyu, 67(4), p.161 - 162, 2018/08
We introduce hard X-ray photoelectron spectroscopy, which has been rapidly introduced and developed in synchrotron radiation facilities. In particular, in order to realize electronic state analysis by hard X-ray photoelectron spectroscopy of insulators, the developed charge neutralization method was described. As an example, we showed adsorption behavior of cesium to nuclear reactor structure assuming Fukushima Daiichi Nuclear Power Plant accident. Finally, future prospects of hard X-ray photoelectron spectroscopy will be described.
Okuno, Mitsuru*; Nagaoka, Shinji*; Kokubu, Yoko; Nakamura, Toshio*; Kobayashi, Tetsuo*
Fukuoka Daigaku Rigaku Shuho, 48(1), p.1 - 5, 2018/03
Kuju volcanic group, located in central Kyushu, Japan, consists of over twenty volcanoes (lava domes as well as small stratovolcanoes). The Kurodake is largest lava dome with a volume of 1.6 km
, and generated Kurodake pyroclastic-flow (Kj-Kd) and ash-fall (Kj-KdA) deposits. To refine age of the Kurodake eruption, we conducted radiocarbon dating of a charcoal fragment in the Kj-Kd with an AMS system at Tono Geoscience Center, JAEA. The obtained 
C date, 150540 BP, can correspond to 1310-1423 cal BP (probability= 74.6%), 1430-1442 cal BP (2.4%) and 1456-1521 cal BP (23.0%) in 2
confidence level. The medium probability date, 1391 cal BP, is consistent with the stratigraphy and gives the reliable age for the Kj-Kd.
Kobata, Masaaki; Okane, Tetsuo; Nakajima, Kunihisa; Suzuki, Eriko; Owada, Kenji; Kobayashi, Keisuke*; Yamagami, Hiroshi; Osaka, Masahiko
Journal of Nuclear Materials, 498, p.387 - 394, 2018/01
Times Cited Count：17 Percentile：86.67(Materials Science, Multidisciplinary)In this study, for the understandings of Cesium (Cs) adsorption behavior on structure materials in severe accidents at a light water nuclear reactor, the chemical state of Cs and its distribution on the surface of SUS304 stainless steel (SS) with different Si concentration were investigated by hard X-ray photoelectron spectroscopy (HAXPES) and scanning electron microscope / energy dispersive X-ray spectroscopy (SEM/EDX). As a result, it was found that Cs is selectively adsorbed at the site where Si distributes with high concentration. CsFeSiO
is a dominant Cs products in the case of low Si content, mainly formed, while Cs
SiO
and CsSiO
are formed in addition to CsFeSiO in the case of high Si content. The chemical forms of the Cs compounds produced in the adsorption process on the SS surface has a close correlation with the concentration and chemical states of Si originally included in SS.
-Ti
O
and 
-TiO studied by hard X-ray photoelectron spectroscopyKobayashi, Keisuke*; Taguchi, Munetaka*; Kobata, Masaaki; Tanaka, Kenji*; Tokoro, Hiroko*; Daimon, Hiroshi*; Okane, Tetsuo; Yamagami, Hiroshi; Ikenaga, Eiji*; Okoshi, Shinichi*
Physical Review B, 95(8), p.085133_1 - 085133_7, 2017/02
Times Cited Count：15 Percentile：56.08(Materials Science, Multidisciplinary)Okuno, Mitsuru*; Nagaoka, Shinji*; Kokubu, Yoko; Nakamura, Toshio*; Kobayashi, Tetsuo*
Radiocarbon, 59(2), p.483 - 488, 2017/00
Times Cited Count：3 Percentile：14.08(Geochemistry & Geophysics)We present here results of AMS C dating to refine the history of the middle and western parts of the Kuju Volcanic Group, located in middle Kyushu, Japan, which consists of more than 20 lava domes and cones. C dating has conducted by AMS (JAEA-AMS-TONO) under the Common-Use Facility Program of JAEA. The Handa PF deposits, which are products of the largest eruption of the group, were dated to 53.5 ka BP. The Shirani and Muro PF deposits, which are block-and-ash flows, were dated to 44 to 
50 cal ka BP and 3539 cal ka BP, respectively. These ages can be correlated with the TL ages for the lava domes. Therefore, both TL and C methods can be useful tools in establishing the eruptive sequence of lava domes and pyroclastic flows. This study also demonstrates that these eruptive activities occurred after the Handa pfl, the biggest eruption during the last 150 kyrs without a significant time interval.
studied by photoelectron spectroscopyKobata, Masaaki; Fujimori, Shinichi; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke*; Yamagami, Hiroshi; Nakamura, Ai*; Hedo, Masato*; Nakama, Takao*; et al.
Journal of the Physical Society of Japan, 85(9), p.094703_1 - 094703_6, 2016/09
Times Cited Count：13 Percentile：62.55(Physics, Multidisciplinary)Ikuta, Masafumi*; Niwa, Masakazu; Danhara, Toru*; Yamashita, Toru*; Maruyama, Seiji*; Kamataki, Takanobu*; Kobayashi, Tetsuo*; Kurosawa, Hideki*; Kokubu, Yoko; Hirata, Takafumi*
Chishitsugaku Zasshi, 122(3), p.89 - 107, 2016/03
We carried out mineral composition analysis, morphological classification of volcanic glass shards and refractive index measurements of the glass shards and orthopyroxene from the eruption products from Sakurajima volcano. In this study, refractive indexes of hydrated and non-hydrated parts within each individual glass shard were measured separately. This measurements in consideration of hydration in glass shards made possible distinct discrimination of the pumice samples from the three eruption events of Bunmei, An-ei, and Taisho. Pumice layers in the core samples obtained from the southern part of the Miyazaki Plain were also identified as the Sakurajima-Bunmei tephra by the above mentioned analyses, and also by the data of radiocarbon dating for coaly materials included in the pumice layers. Occurrences of the pumice layers suggest that the Sakurajima-Bunmei tephra could have reached the southern part of Miyazaki Plain as pumice falls.
Okane, Tetsuo; Kobata, Masaaki; Sato, Isamu*; Kobayashi, Keisuke*; Osaka, Masahiko; Yamagami, Hiroshi
Nuclear Engineering and Design, 297, p.251 - 256, 2016/02
Times Cited Count：2 Percentile：19.71(Nuclear Science & Technology)Fukuda, Tetsuya*; Tanase, Atsushi*; Umeda, Koji; Kobayashi, Tetsuo*
Gekkan Chikyu, 37(5), p.197 - 203, 2015/05
no abstracts in English
Mirabueno, M. H. T.*; Torii, Masayuki*; Laguerta, E. P.*; Delos Reyes, P. J.*; Fujiki, Toshiyuki*; Bariso, E. B.*; Okuno, Mitsuru*; Nakamura, Toshio*; Danhara, Toru*; Kokubu, Yoko; et al.
Chigaku Zasshi, 123(5), p.751 - 760, 2014/10
Core drilling at site IRBH-2 within Irosin caldera, southern Luzon, reached 50 m. Systematic logging and documentation were done to describe the sediments. AMS C dates were obtained for plant fragments from the peaty layers. Lahars and fluvial deposits were the predominant deposits in the core sequence. The upper 12 m was comprised mostly by andesitic fluvial and minor lahars. Eight fallouts were intercalated with reworked sediments from depth interval of 20 to 50 m. The refractive index measurement of analyzed samples indicated that post-caldera eruptions generated andesite, dacite and minor rhyolite. The similarity in petrographic characteristics between the rhyolite fallout and the Irosin ignimbrite indicates that small-scale eruptions involving magma from the caldera event occurred during post-caldera stage.Young radiocarbon dates obtained from the peaty layers shows that volcaniclastic deposits in the upper levels were likely derived from the eruptions of Bulusan volcano.
-type ferromagnetic semiconductor (In,Fe)AsKobayashi, Masaki*; Anh, L. D.*; Hai, P. N.*; Takeda, Yukiharu; Sakamoto, Shoya*; Kadono, Toshiharu*; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi; Harada, Yoshihisa*; et al.
Applied Physics Letters, 105(3), p.032403_1 - 032403_4, 2014/07
Times Cited Count：6 Percentile：26.85(Physics, Applied)Okuno, Mitsuru*; Nakamura, Toshio*; Geshi, Nobuo*; Kimura, Katsuhiko*; Kokubu, Yoko; Kobayashi, Tetsuo*
Nuclear Instruments and Methods in Physics Research B, 294, p.602 - 605, 2013/01
Times Cited Count：4 Percentile：33.02(Instruments & Instrumentation)We found numerous wood trunks from pumiceous deposits along Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island, and conducted radiocarbon dating using accelerator mass spectrometry (AMS). The obtained C dates were around 6500 BP, and geological characteristics of the pumiceous deposits indicate that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, they are not charred, suggesting that the origin of these deposits is not of pyroclastic flow but that of tsunami. Fourteen taxa were identified through anatomical characteristics. This is the first discovery on species of the forest of the Yakushima Island before the devastating eruption.
Obara, Satoshi*; Kobayashi, Ryoei*; Yagi, Shuichi*; Toyama, Yuko*; Kutluk, G.*; Osawa, Tetsutaro*; Ogura, Koichi; Shibata, Takemasa; Azuma, Yoshiro*; Nagata, Tetsuo*
Nuclear Instruments and Methods in Physics Research B, 269(3), p.263 - 271, 2011/02
Times Cited Count：0 Percentile：0.01(Instruments & Instrumentation)A crossed photon-atom beam apparatus has been constructed for absolute measurement of total photoionization cross sections of isolated and neutral metallic atoms. Using this apparatus, measurements on Ba and Eu atoms have been made at their 4d giant resonance regions 110-140 eV and 140-180 eV, respectively. The target atom density was determined using the deposition rate on a quartz crystal sensor and the average velocity of the atoms obtained by a time-of-flight method combined with a pulsed electron gun. The number of photons was determined with use of a double ion chamber. The comparison of the measured cross-section values with previous experimental and theoretical results is reasonable, indicating that the crossed photon-atom beam method is fairly promising technique.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Kataoka, Takashi*; Kobayashi, Masaki*; Sakamoto, Yuta*; Song, G. S.*; Fujimori, Atsushi*; Chang, F.-H.*; Lin, H.-J.*; Huang, D. J.*; Chen, C. T.*; Okochi, Takuo*; et al.
Journal of Applied Physics, 107(3), p.033718_1 - 033718_7, 2010/02
Times Cited Count：54 Percentile：86.13(Physics, Applied)
Co
OKobayashi, 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：61.85(Materials Science, Multidisciplinary)Mn
As studied by X-ray magnetic circular dichroismTakeda, Yukiharu; Kobayashi, Masaki*; Okane, Tetsuo; Okochi, Takuo*; Okamoto, Jun*; Saito, Yuji; Kobayashi, Keisuke*; Yamagami, Hiroshi; Fujimori, Atsushi*; Tanaka, Arata*; et al.
Hoshako, 22(4), p.202 - 209, 2009/07
no abstracts in English
Tomimoto, Hiroshi; Kato, Yasushi; Owada, Hiroyuki; Sato, Nao; Shimazaki, Yosuke; Kozawa, Takayuki; Shinohara, Masanori; Hamamoto, Shimpei; Tochio, Daisuke; Nojiri, Naoki; et al.
JAEA-Technology 2009-025, 29 Pages, 2009/06
JAEA-Technology-2009-025.pdf:21.78MB
The first driver fuel of the HTTR (High Temperature Engineering test Reactor) was loaded in 1998 and the HTTR reached first criticality state in the same year. The HTTR has been operated using the first driver fuel for a decade. In Fuel elements assembling, 4770 of fuel rods which consist of 12 kinds of enrichment uranium are loaded into 150 fuel graphite blocks for HTTR second driver fuel elements. Measures of prevention of fuel rod miss loading, are employed in fuel design. Additionally, precaution of fuel handling on assembling are considered. Reception of fuel rods, assembling of fuel elements and storage of second driver fuels in the fresh fuel storage rack in the HTTR were started since June, 2008. Assembling, storage and pre-service inspection were divided into three parts. The second driver fuel assembling was completed in September, 2008. This report describes concerns of fuel handling on assembling and storage work for the HTTR fuel elements.
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：12 Percentile：44.93(Physics, Applied)