Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tanaka, Kazuya; Yamaji, Keiko*; Masuya, Hayato*; Tomita, Jumpei; Ozawa, Mayumi*; Yamasaki, Shinya*; Tokunaga, Kohei; Fukuyama, Kenjin*; Ohara, Yoshiyuki*; Maamoun, I.*; et al.
Chemosphere, 355, p.141837_1 - 141837_11, 2024/05
In this study, biogenic Mn(IV) oxide was applied to remove Ra from mine water collected from a U mill tailings pond in the Ningyo-toge center. Just 7.6 mg of biogenic Mn(IV) oxide removed more than 98% of the Ra from 3 L of mine water, corresponding to a distribution coefficient of 10 mL/g for Ra at pH 7. The obtained value was convincingly high for practical application of biogenic Mn(IV) oxide in water treatment.
Li, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count:4 Percentile:31.9(Chemistry, Analytical)no abstracts in English
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08
Times Cited Count:1 Percentile:11.15(Engineering, Electrical & Electronic)A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07
Times Cited Count:15 Percentile:79.44(Physics, Multidisciplinary)We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic and X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the -shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.
Sakon, Atsushi*; Nakajima, Kunihiro*; Takahashi, Kazuki*; Hohara, Shinya*; Sano, Tadafumi*; Fukaya, Yuji; Hashimoto, Kengo*
EPJ Web of Conferences, 247, p.09009_1 - 09009_8, 2021/02
In graphite-reflected thermal reactors, even a detector placed far from fuel region may detect a certain degree of the correlation amplitude. This is because mean free path of neutrons in graphite is longer than that in water or polyethylene. The objective of this study is experimentally to confirm a high flexibility of neutron detector placement in graphite reflector for reactor noise analysis. The present reactor noise analysis was carried out in a graphite-moderated and -reflected thermal core in Kyoto University Critical Assembly (KUCA). BF proportional neutron counters (1" dia.) were placed in graphite reflector region, where the counters were separated by about 35cm and 30cm -thick graphite from the core, respectively. At a critical state and subcritical states, time-sequence signal data from these counters were acquired and analyzed by a fast Fourier transform (FFT) analyzer, to obtain power spectral density in frequency domain. The auto-power spectral density obtained from the counters far from the core contained a significant degree of correlated component. A least-squares fit of a familiar formula to the auto-power spectral density data was made to determine the prompt-neutron decay constant. The decay constant was 63.314.5 [1/s] in critical state. The decay constant determined from the cross-power spectral density and coherence function data between the two counters also had a consistent value. It is confirmed that reactor noise analysis is possible using a detector placed at about 35cm far from the core, as we expected.
Tanaka, Kazuya; Watanabe, Naoko*; Yamasaki, Shinya*; Sakaguchi, Aya*; Fan, Q.*; Takahashi, Yoshio*
Geochemical Journal, 52(2), p.173 - 185, 2018/00
Times Cited Count:9 Percentile:43.3(Geochemistry & Geophysics)We analyzed riverbed sediments collected at two sites, Yamakiya and Kuroiwa, in Fukushima after the Fukushima accident. The size distributions of K, Rb, and Csreflected the mineralogy of sediments, where primary host minerals for these alkali elements would be biotite, K-feldspar, and clay minerals. Silt-size fractions contained high Cs and Cs concentrations possibly due to adsorption on clay minerals. Their concentrations decreased with particle size at the Yamakiya site. In contrast, coarse and very coarse sand fractions from the Kuroiwa site showed higher Cs and Cs concentrations in comparison to fine - medium sand fractions. The coarse sand fractions contained many weathered biotite grains. Overall, the size distributions of Cs and Cs were similar in the sediments, suggesting that the Fukushima-derived radiocesium was distributed into each particle size fraction in response to the distribution of the stable Cs that was controlled by mineralogical composition.
Hu, W.*; Hayashi, Koichi*; Fukumura, Tomoteru*; Akagi, Kazuto*; Tsukada, Masaru*; Happo, Naohisa*; Hosokawa, Shinya*; Owada, Kenji; Takahashi, Masamitsu; Suzuki, Motohiro*; et al.
Applied Physics Letters, 106(22), p.222403_1 - 222403_5, 2015/06
Times Cited Count:39 Percentile:81.57(Physics, Applied)Kasai, Shinya*; Hirayama, Yusuke*; Takahashi, Yukiko*; Mitani, Seiji*; Hono, Kazuhiro*; Adachi, Hiroto; Ieda, Junichi; Maekawa, Sadamichi
Applied Physics Letters, 104(16), p.162410_1 - 162410_4, 2014/04
Times Cited Count:14 Percentile:52.23(Physics, Applied)Hu, W.*; Hayashi, Koichi*; Owada, Kenji; Chen, J.*; Happo, Naohisa*; Hosokawa, Shinya*; Takahashi, Masamitsu; Bokov, A.*; Ye, Z.-G*
Physical Review B, 89(14), p.140103_1 - 140103_5, 2014/04
Times Cited Count:48 Percentile:85.62(Materials Science, Multidisciplinary)Odaka, Hirokazu*; Ichinohe, Yuto*; Takeda, Shinichiro*; Fukuyama, Taro*; Hagino, Koichi*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; Watanabe, Shin*; Kokubun, Motohide*; et al.
Nuclear Instruments and Methods in Physics Research A, 695, p.179 - 183, 2012/12
Times Cited Count:23 Percentile:84.01(Instruments & Instrumentation)We have developed a new Si/CdTe semiconductor double-sided strip detector (DSD) Compton camera. The camera consists of a 500-m-thick Si-DSD and four layers of 750-m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 degrees at 356 keV and 3.5 degrees at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.
Takeda, Shinichiro*; Ichinohe, Yuto*; Hagino, Koichi*; Odaka, Hirokazu*; Yuasa, Takayuki*; Ishikawa, Shinnosuke*; Fukuyama, Taro*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; et al.
Physics Procedia, 37, p.859 - 866, 2012/10
Times Cited Count:23 Percentile:98.43(Physics, Applied)By using new Compton camera consisting of silicon double-sided strip detector (Si-DSD) and CdTe-DSD developed for the ASTRO-H mission, an experiment was conducted to study its feasibility for advanced hotspot monitoring. In addition to hotspot imaging already provided by commercial imaging systems, the identification of the variety of radioisotopes is realized thanks to the good energy resolution given by the semiconductor detectors. Three radioisotopes of Ba (356 keV), Na (511 keV) and Cs (662 keV) were individually imaged by applying event selection in the energy window and the -ray images was correctly overlapped by an optical picture. The detection efficiency of 1.6810 (effective area: 1.710 cm) and angular resolution of 3.8 were obtained by stacking five detector modules for 662 keV -ray. The higher detection efficiency required in a specific use can be achieved by stacking more detector modules.
Nakagawa, Mayu*; Takahashi, Shinya*; Narumi, Issei; Sakamoto, Ayako
Plant Signaling & Behavior (Internet), 6(5), p.728 - 731, 2011/05
Nakagawa, Mayu*; Takahashi, Shinya*; Tanaka, Atsushi; Narumi, Issei; Sakamoto, Ayako
Plant Physiology, 155(1), p.414 - 420, 2011/01
Times Cited Count:15 Percentile:43.37(Plant Sciences)no abstracts in English
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.
Matsui, Yoshinori; Takahashi, Hiroyuki; Yamamoto, Masaya; Nakata, Masahito; Yoshitake, Tsunemitsu; Abe, Kazuyuki; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; et al.
JAEA-Technology 2009-072, 144 Pages, 2010/03
"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.
Takahashi, Shinya*; Inoue, Takanobu*; Tsushima, Koji*; Sakioka, Masamichi*; Matsunaga, Takeshi
Kankyo Kogaku Kenkyu Rombunshu, 46, p.565 - 572, 2009/00
This study analyzed the changes of water quality during rain events at Ijira river, a mountain stream in Gifu Prefecture, by measured the major ion concentration, pH, electric conductivity, discharge, and hydrograph separation using deuterium isotope ratio of the water. During rain events, where the discharge is increase, almost all of the major ion concentration, pH and electric conductivity were decreased. We also found that the correlation of the changes of pH and the changes of electric conductivity with precipitation were negative. The result of hydrograph separation shows that the ratio of surface runoff for discharge is increased with an increased of the precipitation, and also increased in the high precipitation. It was shown that the major factor of the changes of water quality in this study site is the contribution of surface runoff.
Takahashi, Shinya*; Nakagawa, Mayu; Tanaka, Atsushi; Narumi, Issei; Shimizu, Kikuo*; Sakamoto, Ayako
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 58, 2008/11
no abstracts in English
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Takahashi, Shinya*; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo*
Plant Physiology, 145(3), p.1052 - 1060, 2007/11
Times Cited Count:15 Percentile:37.73(Plant Sciences)To clarify the functions of AtREV1 protein, we expressed it in E. coli and purified it. The deoxynucleotidyl transferase activity of the recombinant AtREV1 was examined in a primer extension assay . The recombinant AtREV1 transferred one or two nucleotides to the primer end. Especially, it efficiently inserted dCMP regardless of the opposite base. AtREV1 also inserted a dCMP opposite the apurinic/apyrimidinic (AP) sites, which are physiologically generated or induced by various DNA-damaging agents. However, AtREV1 had no insertion activities against UV-inducible DNA lesions. Although the substrate specificity of AtREV1 was rather narrow in the presence of magnesium ion, it widened in the presence of manganese ion. These results suggest that AtREV1 serves as a deoxycytidyl transferase in plant cells.
Inoue, Kazuhiko*; Shibamoto, Hiroshi*; Takahashi, Kenji; Ikutama, Shinya*; Morishita, Masaki; Aoto, Kazumi; Kasahara, Naoto; Asayama, Tai; Kitamura, Seiji
Nihon Genshiryoku Gakkai-Shi, 48(5), p.333 - 338, 2006/05
no abstracts in English