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Onoe, Hironori*; Yoshida, Fumiko*; Hamamoto, Takafumi*; Saegusa, Hiromitsu*; Ishida, Keisuke*; Sawada, Atsushi
NUMO-TR-24-03, p.71 - 75, 2024/10
no abstracts in English
Yoshida, Keisuke; Kato, Shingo; Okuyama, Shinichi; Ishimori, Yuu; Inoue, Mutsuo*
Journal of Nuclear and Radiochemical Sciences (Internet), 24, p.1 - 12, 2024/08
Ichikawa, Tsubasa*; Hakoshima, Hideaki*; Inui, Koji*; Ito, Kosuke*; Matsuda, Ryo*; Mitarai, Kosuke*; Miyamoto, Koichi*; Mizukami, Wataru*; Mizuta, Kaoru*; Mori, Toshio*; et al.
Nature Reviews Physics (Internet), 6(6), p.345 - 347, 2024/06
Times Cited Count:2 Percentile:51.04(Physics, Applied)Kamada, Masaki*; Yoshida, Takuma*; Sugita, Tsukasa*; Okumura, Keisuke
Nihon Genshiryoku Gakkai-Shi ATOMO, 66(2), p.83 - 86, 2024/02
no abstracts in English
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:43.49(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.
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
Nakano, Masaki*; Wang, Y.*; Yoshida, Satoshi*; Matsuoka, Hideki*; Majima, Yuki*; Ikeda, Keisuke*; Hirata, Yasuyuki*; Takeda, Yukiharu; Wadachi, Hiroki*; Kohama, Yoshimitsu*; et al.
Nano Letters, 19(12), p.8806 - 8810, 2019/12
Times Cited Count:60 Percentile:91.34(Chemistry, Multidisciplinary)Kawasaki, Masatsugu; Nakajima, Junya; Yoshida, Keisuke; Kato, Saori; Nishino, Sho; Nozaki, Teo; Nakagawa, Masahiro; Tsunoda, Junichi; Sugaya, Yuki; Hasegawa, Rie; et al.
JAEA-Data/Code 2017-004, 57 Pages, 2017/03
In emergency situation of nuclear facilities, we need to estimate the radiation dose due to radiation and radioactivity to grasp the influence range of the accident in the early stage. Therefore, we prepare the case studies of dose assessment for public exposure dose and personal exposure dose and contribute them to emergency procedures. This document covers about accidents of nuclear facilities in Nuclear Science Research Institute and past accident of nuclear power plant, and it can be used for inheritance of techniques of emergency dose assessment.
Yoshida, Fumiko; Nagashima, Keisuke; Tsubouchi, Masaaki; Ochi, Yoshihiro; Maruyama, Momoko; Sugiyama, Akira
Japanese Journal of Applied Physics, 55(1), p.012201_1 - 012201_5, 2016/01
Times Cited Count:6 Percentile:27.48(Physics, Applied)Yuyama, Takahiro; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Ishizaka, Tomohisa; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Usui, Aya; Miyawaki, Nobumasa; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.302 - 304, 2015/09
no abstracts in English
Ishigami, Keisuke*; Yoshimatsu, Kohei*; Toyota, Daisuke*; Takizawa, Masaru*; Yoshida, Teppei*; Shibata, Goro*; Harano, Takayuki*; Takahashi, Yukio*; Kadono, Toshiharu*; Verma, V. K.*; et al.
Physical Review B, 92(6), p.064402_1 - 064402_5, 2015/08
Times Cited Count:47 Percentile:83.92(Materials Science, Multidisciplinary)Ochi, Yoshihiro; Nagashima, Keisuke; Maruyama, Momoko; Tsubouchi, Masaaki; Yoshida, Fumiko; Kono, Nanase; Mori, Michiaki; Sugiyama, Akira
Optics Express (Internet), 23(11), p.15057 - 15064, 2015/06
Times Cited Count:29 Percentile:78.88(Optics)We have developed a 1 kHz repetition picosecond laser system dedicated for intense terahertz (THz) pulse generation. The system comprises a chirped pulse amplification laser equipped with a Yb:YAG thin-disk amplifier. At room temperature, the Yb:YAG thin-disk regenerative amplifier provides pulses having energy of over 10 mJ and spectral bandwidth of 1.2 nm. The pulse duration achieved after passage through a diffraction grating pair compressor was 1.3 ps. By employing this picosecond laser as a pump source, THz pulses having a peak frequency of 0.3 THz and 4 J of energy were generated by means of optical rectification in an Mg-doped LiNbO
crystal.
Tsubouchi, Masaaki; Nagashima, Keisuke; Yoshida, Fumiko; Ochi, Yoshihiro; Maruyama, Momoko
Optics Letters, 39(18), p.5439 - 5442, 2014/09
Times Cited Count:36 Percentile:84.97(Optics)A novel design for a contact grating device with an incorporated Fabry-Perot resonator is proposed for high-power terahertz light (THz) generation. We deposited a multilayer consisting of TaO
and Al
O
on a magnesium-doped stoichiometric LiNbO
substrate and fabricated grating grooves on the outermost layer. The multilayer was designed such that conditions for a Fabry-Perot resonator were satisfied for light diffracted by the grating. Consequently, the fraction of light transmitted into the LiNbO
substrate, i.e., the diffraction efficiency, was enhanced by the resonator. The diffraction efficiency of the fabricated device was 71%, which is close to the calculated value of 78% from the optimized design. THz light generation was also demonstrated with the contact grating device. The THz output of 0.41 microJ was obtained using NIR pump light of 2.7 mJ.
Yamada, Katsunori; Fujii, Katsutoshi; Kanda, Hiroshi; Higashi, Daisuke; Kobayashi, Toshiaki; Nakagawa, Masahiro; Fukami, Tomoyo; Yoshida, Keisuke; Ueno, Yumi; Nakajima, Junya; et al.
JAEA-Review 2013-033, 51 Pages, 2013/12
After the accident at Fukushima Dai-ichi Nuclear Power Plant, various numerical criteria relevant to radiation protection were defined. We surveyed these criteria through internet. As a result of survey, the following 13 items were identified: (1) criteria for taking stable iodine tablets, (2) criteria for the screening of surface contamination, (3) evacuation area, sheltering area, etc., (4) activity concentrations in food, drinking water, etc., (5) dose limit for radiation workers engaged in emergency work, (6) guideline levels of radioactive substances in bathing areas, (7) criteria for use of school buildings and schoolyards, (8) restriction on planting rice, (9) acceptable activity concentrations in feedstuff, (10) acceptable activity concentrations in compost, (11) criteria for export containers and ships, (12) criteria for contaminated waste, (13) standards for radiation workers engaged in decontamination work. In this report, the basis of and issues on these criteria are summarized.
Kawaguchi, Yuko*; Yang, Y.*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Takasu, Masako*; Narumi, Issey*; Sato, Katsuya; Hashimoto, Hirofumi*; Nakagawa, Kazumichi*; Tanigawa, Yoshiaki*; et al.
Origins of Life and Evolution of Biospheres, 43(4-5), p.411 - 428, 2013/10
Times Cited Count:42 Percentile:80.12(Biology)Ito, Chikara; Ito, Keisuke; Ishikawa, Takashi; Yoshida, Akihiro; Sanada, Yukihisa; Torii, Tatsuo; Notomi, Akihiro*; Wakabayashi, Genichiro*; Miyazaki, Nobuyuki*
Hoshasen, 39(1), p.7 - 11, 2013/09
no abstracts in English
Nagase, Fumihisa; Ishikawa, Jun; Kurata, Masaki; Yoshida, Hiroyuki; Kaji, Yoshiyuki; Shibamoto, Yasuteru; Amaya, Masaki; Okumura, Keisuke; Katsuyama, Jinya
Proceedings of International Nuclear Fuel Cycle Conference; Nuclear Energy at a Crossroads (GLOBAL 2013) (CD-ROM), p.711 - 720, 2013/09
Estimation of the accident progress and status inside the reactor is required to properly and reliably conduct decommissioning of the Fukushima-Daiichi NPPs. For that, it is necessary to obtain additional experimental data and revised models for the estimation using computer codes with increased accuracies. JAEA has selected phenomena to be reviewed and developed in terms of thermo hydraulic behavior in the reactor, progression of fuel bundle degradation, failure of the lower head of the reactor pressure vessel, and analysis of the accident, considering previously obtained information, conditions specific to the Fukushima-Daiichi NPP accident, and recent progress of experimental and analytical technologies. This paper introduces the selected phenomena to be reviewed and developed and recent results from the JAEA's corresponding research programs.
Yoshida, Fumiko; Tanaka, Momoko; Nagashima, Keisuke
Thin Solid Films, 537, p.23 - 27, 2013/06
Times Cited Count:2 Percentile:9.53(Materials Science, Multidisciplinary)Okumura, Susumu; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; Nara, Takayuki; et al.
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 172, 2013/01
The AVF cyclotron was operated from May 9th in fiscal 2011 and all the planned experiments on April were cancelled due to scheduled blackouts originated from the Great East Japan Earthquake. The total operation time amounted to 3,038.4 hours. The extended operation from Friday evening to Saturday evening was carried out eight times in order to supply the cancellation on April. The regular yearly overhaul and maintenance were carried out.
Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.
Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10
Times Cited Count:175 Percentile:97.25(Physics, Multidisciplinary)An isotope of the 113th element, 113, was produced in a nuclear reaction with a
Zn beam on a
Bi target. We observed six consecutive
decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of
Db and
Lr both in decay energies and decay times. This indicates that the present decay chain consisted of
113,
Rg (Z = 111),
Mt (Z = 109),
Bh (Z = 107),
Db (Z = 105), and
Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope
113, of the 113th element.