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Sweet, M.*; Mishima, Kenji*; Harada, Masahide; Kurita, Keisuke; Iikura, Hiroshi; Tasaki, Seiji*; Kikuchi, Norio*
Quantum Beam Science (Internet), 9(2), p.11_1 - 11_17, 2025/04
Neutron beam, being electrically neutral and highly penetrating, offers unique advantages for irradiation of biological species such as plants, seeds, and microorganisms. We comprehensively investigated the potential of neutron irradiation for inducing genetic mutations using simulations of J-PARC BL10, JRR-3 TNRF, and KUANS for spallation, reactor, and compact neutron sources.
C and 500CTakagi, Honoka*; Yabutsuka, Takeshi*; Hayashida, Hirotoshi*; Song, F.; Kai, Tetsuya; Shinohara, Takenao; Kurita, Keisuke; Iikura, Hiroshi; Yamamoto, Norio*; Nakajima, Minoru*; et al.
Solid State Ionics, 417, p.116716_1 - 116716_7, 2024/12
Times Cited Count：0 Percentile：0.00(Chemistry, Physical)Ito, Daisuke*; Odaira, Naoya*; Ito, Kei*; Saito, Yasushi*; Kurita, Keisuke; Iikura, Hiroshi
Journal of Physics; Conference Series, 2605, p.012024_1 - 012024_6, 2023/10
Gas-liquid two-phase flow appears in many heat-exchanging devices. To understand the phenomena in such devices, the two-phase flow dynamics should be clarified. In this study, high-speed neutron imaging is applied to the measurements of two-phase flow dynamics, and the accuracy of the void fraction measurement is investigated.
Saito, Yasushi*; Ito, Daisuke*; Odaira, Naoya*; Kurita, Keisuke; Iikura, Hiroshi
Journal of Physics; Conference Series, 2605, p.012028_1 - 012028_6, 2023/10
To observe flow velocity distributions by Neutron Imaging, suitable tracer is necessary. The requirements are its density, its visibility, and its wettability (if applied to liquid metal). Gold cadmium tracers have been developed for the Pb-Bi two-phase flow, however, the visibility have not been verified depending on the particle size and the measurement system. As the candidates of tracer particles, Ag, Cd, Au-Cd, and Ag-Cd have been tested by varying its compositions and its diameters. Results show enough visibility if the particles size is larger than 1mm. In addition, Cd tracer particles were applied to the fluidized bed, where the bed materials are metallic particle made of stainless steel, with 1mm diameter. The diameter of Cd trace is about 1.5 mm. From the neutron imaging, the visibility of the tracers is enough to measure the velocity distributions in the fluidized bed.
Kurita, Keisuke; Iikura, Hiroshi; Tsuchikawa, Yusuke; Kai, Tetsuya; Shinohara, Takenao; Odaira, Naoya*; Ito, Daisuke*; Saito, Yasushi*; Matsubayashi, Masahito
Journal of Physics; Conference Series, 2605, p.012005_1 - 012005_6, 2023/10
The Japan Research Ractor-3 (JRR-3) is operation resumed on February 26, 2021, and the shared use was also restarted in July, 2021. With the resumption of JRR-3 operation, two imaging facilities called TNRF and CNRF have also resumed their utilization. In this presentation, we report the details of these two neutron facilities.
Cs in river waterEnomoto, Kazuyuki*; Hoshina, Hiroyuki*; Kasai, Noboru*; Kurita, Keisuke; Ueki, Yuji*; Nagao, Yuto*; Yin, Y.-G.*; Suzui, Nobuo*; Kawachi, Naoki*; Seko, Noriaki*
Chemical Engineering Journal, 460, p.141696_1 - 141696_9, 2023/03
Times Cited Count：2 Percentile：19.31(Engineering, Environmental)This study develops a method that combines a radiation-grafting fibrous Cs-adsorbent filter of ammonium molybdophosphate (AMP) and a Ce:Gd
Al
GaO
scintillator based 
-ray detector for in situ measurements of the activity concentrations of Cs in a continuous water flow.
Ito, Daisuke*; Odaira, Naoya*; Ito, Kei*; Saito, Yasushi*; Kurita, Keisuke; Iikura, Hiroshi
Konsoryu, 37(1), p.73 - 78, 2023/03
Gas-liquid two-phase flow is a very complicated flow phenomenon that involves the interaction between gas and liquid phases. Recently, an accurate simulation technique of two-phase flow has been developed. However, the validation of the simulated results is insufficient due to less experimental data. It is especially difficult to measure interfacial behavior with significant spatiotemporal fluctuation. To understand such phenomena, measurement methods with high spatial and temporal resolutions are required. Neutron imaging is a powerful tool for two-phase flow visualization. In this study, two-phase flow in the narrow rectangular channel was visualized by high-speed neutron imaging.
Hosokawa, Takayuki*; Yasue, Ayumu*; Kim, J.*; Kurita, Keisuke; Kanematsu, Manabu*
Konkurito Kozobutsu No Hoshu, Hokyo, Appuguredo Rombun Hokokushu (CD-ROM), 22, p.113 - 118, 2022/10
no abstracts in English
Kuroda, Rikuto*; Matsumoto, Ryosuke*; Oda, Yutaka*; Fukai, Ao*; Kida, Kenta*; Iikura, Hiroshi; Kurita, Keisuke
2022-Nendo Nihon Reito Kucho Gakkai Nenji Taikai Koen Rombunshu, 6 Pages, 2022/09
Frost formation causes the thermal resistance for the heat transfer performance on the heat exchanger. In this study, the frost distribution on the heat exchanger used in the automobile air conditioning system was evaluated by neutron radiography imaging. At the initial stage of the frost formation, the frost formed in the upstream side of the heat exchanger. The frost deposited in the downstream region of the heat exchanger as time proceeds.
Higuchi, Kyoko*; Kurita, Keisuke; Sakai, Takuro; Suzui, Nobuo*; Sasaki, Minori*; Katori, Maya*; Wakabayashi, Yuna*; Majima, Yuta*; Saito, Akihiro*; Oyama, Takuji*; et al.
Plants (Internet), 11(6), p.817_1 - 817_11, 2022/03
Times Cited Count：3 Percentile：27.96(Plant Sciences)Genetic diversity in the rate of Fe uptake by plants has not been broadly surveyed among plant species or genotypes, although plants have developed various Fe acquisition mechanisms. We adopted the "Live-autoradiography" technique with radioactive 
Fe to directly evaluate the uptake rate of Fe by barley cultivars from a nutrient solution containing a very low concentration of Fe. Our observations revealed that the ability to acquire Fe from the low Fe solution was not always the sole determinant of tolerance to Fe deficiency among the barley genotypes.
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：7 Percentile：40.14(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Yin, Y.-G.*; Mori, Yoshinao*; Suzui, Nobuo*; Kurita, Keisuke; Yamaguchi, Mitsutaka*; Miyoshi, Yuta*; Nagao, Yuto*; Ashikari, Motoyuki*; Nagai, Keisuke*; Kawachi, Naoki*
New Phytologist, 232(5), p.1974 - 1984, 2021/12
Times Cited Count：12 Percentile：65.07(Plant Sciences)Rice (
) plants have porous or hollow organs consisting of aerenchyma, which is presumed to function as a low-resistance diffusion pathway for air to travel from the foliage above the water to submerged organs. However, gas movement in rice plants has yet to be visualized in real time. In this study involving partially submerged rice plants, the leaves emerging from the water were fed nitrogen-13-labeled nitrogen ([
N]N) tracer gas, and the gas movement downward along the leaf blade, leaf sheath, and internode over time was monitored.
Kurita, Keisuke; Sakai, Takuro; Suzui, Nobuo*; Yin, Y.-G.*; Sugita, Ryohei*; Kobayashi, Natsuko*; Tanoi, Keitaro*; Kawachi, Naoki*
Japanese Journal of Applied Physics, 60(11), p.116501_1 - 116501_4, 2021/11
Times Cited Count：2 Percentile：11.10(Physics, Applied)Radioisotope tracer imaging is useful for studying plant physiological phenomena. In this study, we developed an autoradiography system with phosphor powder (ZnS:Ag), "Live-autoradiography", for imaging radioisotope dynamics in a living plant. This system visualizes the element migration and accumulation in intact plants continuously under a light environment. An imaging test was performed on point sources of Cs, with a radioactivity of 10-100 kBq of being observed; this indicates satisfactory system linearity between the image intensity and the radioactivity of Cs. Moreover, dynamics imaging of Cs was performed on an intact soybean plant for four days. The serial images indicated Cs accumulation in the node, vein, and growing point of the plant. The developed system can be used for studying plant physiological phenomena and can be employed for quantitative measurement of radionuclides.
C-imaging revealed the spatiotemporal variability in the translocation of photosynthates into strawberry fruits in response to increasing daylight integrals at leaf surfaceMiyoshi, Yuta*; Hidaka, Kota*; Yin, Y.-G.*; Suzui, Nobuo*; Kurita, Keisuke; Kawachi, Naoki*
Frontiers in Plant Science (Internet), 12, p.688887_1 - 688887_14, 2021/07
Times Cited Count：15 Percentile：72.96(Plant Sciences)In this study, C-photosynthate translocation into strawberry fruits in individual plants was visualized non-invasively and repeatedly using a positron emission tracer imaging system (PETIS) to assess the spatiotemporal variability in the translocation dynamics in response to increasing daylight integrals. This is the first study to use C-radioisotopes to clarify the spatiotemporal variability in photosynthate translocation from source leaves to individual sink fruits in vivo in response to increasing daylight integrals at a high spatiotemporal resolution.
Kurita, Keisuke; Miyoshi, Yuta*; Nagao, Yuto*; Yamaguchi, Mitsutaka*; Suzui, Nobuo*; Yin, Y.-G.*; Ishii, Satomi*; Kawachi, Naoki*; Hidaka, Kota*; Yoshida, Eiji*; et al.
QST-M-29; QST Takasaki Annual Report 2019, P. 106, 2021/03
Kurita, Keisuke; Iikura, Hiroshi
Hamon, 31(1), p.11 - 13, 2021/02
no abstracts in English
Yamamoto, Seiichi*; Nagao, Yuto*; Kurita, Keisuke; Yamaguchi, Mitsutaka*; Kawachi, Naoki*
Journal of Instrumentation (Internet), 16(1), p.P01007_1 - P01007_9, 2021/01
Times Cited Count：0 Percentile：0.00(Instruments & Instrumentation)Luminescence of water during irradiation with particles having energies below the Cerenkov-light threshold was recently found for various types of radiations. However, the relation between the intensities of Cerenkov light and of the luminescence of water at the beam energy below the Cherenkov threshold is not well known. To clarify this point, we measured the produced light irradiating a water sample with electron beams having maximum energies above and below the Cerenkov-light threshold.
Sasa, Kimikazu*; Honda, Maki; Hosoya, Seiji*; Takahashi, Tsutomu*; Takano, Kenta*; Ochiai, Yuta*; Sakaguchi, Aya*; Kurita, Saori*; Satou, Yukihiko; Sueki, Keisuke*
Journal of Nuclear Science and Technology, 58(1), p.72 - 79, 2021/01
Times Cited Count：12 Percentile：75.85(Nuclear Science & Technology)
Cs tracerSuzui, Nobuo*; Shibata, Takuya; Yin, Y.-G.*; Funaki, Yoshihito*; Kurita, Keisuke; Hoshina, Hiroyuki*; Yamaguchi, Mitsutaka*; Fujimaki, Shu*; Seko, Noriaki*; Watabe, Hiroshi*; et al.
Scientific Reports (Internet), 10, p.16155_1 - 16155_9, 2020/10
Times Cited Count：2 Percentile：18.14(Multidisciplinary Sciences)Yin, Y.-G.*; Suzui, Nobuo*; Kurita, Keisuke; Miyoshi, Yuta*; Unno, Yusuke*; Fujimaki, Shu*; Nakamura, Takuji*; Shinano, Takuro*; Kawachi, Naoki*
Scientific Reports (Internet), 10, p.8446_1 - 8446_11, 2020/06
Times Cited Count：11 Percentile：51.99(Multidisciplinary Sciences)The release of rhizodeposits differs depending on the root position and is closely related to the assimilated carbon (C) supply. Therefore, quantifying the C partitioning over a short period may provide crucial information for clarifying root-soil carbon metabolism. A non-invasive method for visualising the translocation of recently assimilated C into the root system inside the rhizobox was established using CO
labelling and the positron-emitting tracer imaging system. The spatial distribution of recent C-photoassimilates translocated and released in the root system and soil were visualised for white lupin (
) and soybean (
). Our method enabled the quantification of the spatial C allocations in roots and soil, which may help to elucidate the relationship between C metabolism and nutrient cycling at specific locations of the root-soil system in response to environmental conditions over relatively short periods.
