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Iwamoto, Yosuke; Yoshida, Makoto*; Meigo, Shinichiro; Yonehara, Katsuya*; Ishida, Taku*; Nakano, Keita; Abe, Shinichiro; Iwamoto, Hiroki; Spina, T.*; Ammigan, K.*; et al.
JAEA-Conf 2021-001, p.138 - 143, 2022/03
To predict the operating lifetime of materials in high-energy radiation environments at proton accelerator facilities, Monte Carlo code are used to calculate the number of displacements per atom (dpa). However, there is no experimental data in the energy region above 30 GeV. In this presentation, we introduce our experimental plan for displacement cross sections with 120-GeV protons at Fermilab Test Beam Facility. Experiments will be performed for the US fiscal year 2022. We developed the sample assembly with four wire sample of Al, Cu, Nb and W with 250-m diameter and 4-cm length. The sample assembly will be maintained at around 4 K by using a cryocooler in a vacuum chamber. Then, changes in the electrical resistivity of samples will be obtained under 120-GeV proton irradiation. Recovery of the accumulated defects through isochronal annealing, which is related to the defect concentration in the sample, will also be measured after the cryogenic irradiation.
Nakano, Masanao; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Okura, Takehisa; Kuramochi, Akihiko; Kawasaki, Masatsugu; Takeuchi, Erina; Fujii, Yutaka*; Jinno, Tsukasa*; et al.
Hoken Butsuri (Internet), 55(2), p.102 - 109, 2020/06
After the Fukushima-Daiichi Nuclear Power Station (1F) Accident in March 2011, the increase was significantly observed in a part of the result of the environmental radiation monitoring in Ibaraki prefecture. "The review meeting of the environmental effect from 1F accident" was established to discuss technically the fluctuation of monitoring data. The review meeting collected the monitoring data from the four nuclear operators, and discussed a fluctuating trend, Cs/Cs activity ratio, and so on. In this report, the results of the dose rate and Cs in fallout, surface soil, flatfish and seabed sediment are introduced. Also the problem solving in the review meeting is introduced.
Hidaka, Akihide; Nakano, Yoshihiro; Watanabe, Yoko; Arai, Nobuyoshi; Sawada, Makoto; Kanaizuka, Seiichi*; Katogi, Aki; Shimada, Mayuka*; Ishikawa, Tomomi*; Ebine, Masako*; et al.
JAEA-Review 2016-011, 208 Pages, 2016/07
JAEA has been conducting the Instructor Training Program (ITP) since 1996 under the auspices of MEXT to contribute to human resource development in currently 11 Asian countries in the field of radiation utilization for seeking peaceful use of nuclear energy. ITP consists of Instructor Training Course (ITC), Follow-up Training Course (FTC) and Nuclear Technology Seminars. In the ITP, trainings or seminars relating to technology for nuclear utilization are held in Japan by inviting nuclear related people from Asian countries to Japan and after that, the past trainees are supported during FTC by dispatching Japanese specialists to Asian countries. News Letter is also prepared to provide the broad range of information obtained through the trainings for local people near NPPs in Japan. The present report describes the activities of FY2014 ITP and future challenges for improving ITP more effectively.
Yamaguchi, Mitsutaka; Nagao, Yuto; Kawachi, Naoki; Sato, Takahiro; Fujimaki, Shu; Kamiya, Tomihiro; Torikai, Kota*; Shimada, Hirofumi*; Sugai, Hiroyuki*; Sakai, Makoto*; et al.
International Journal of PIXE, 26(1&2), p.61 - 72, 2016/00
no abstracts in English
Takahashi, Akihisa*; Kubo, Makoto*; Igarashi, Chie*; Yoshida, Yukari*; Funayama, Tomoo; Kobayashi, Yasuhiko; Nakano, Takashi*
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 82, 2015/03
DNA double-strand breaks (DSBs) induced by ionizing radiation pose a major threat to cell survival. The cell can respond to the presence of DSBs, through two major repair pathways: Homologous recombination (HR) and non-homologous end-joining (NHEJ). Higher levels of cell death are induced by high-LET radiation when compared to low-LET radiation, even at the same doses because of less effective or more inefficient DNA repair. In this study, we examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Wild-type cells and HR deficient (but NHEJ proficient) cells exhibited the high RBE values at LET values of 108 keV/ m. The RBE value for each cell type decreased with increasing LET values over 200 keV/m. Although NHEJ proficient cells had an almost constant SER value, NHEJ deficient cells showed a high SER value when compared to NHEJ proficient cells, even with increasing LET values.
Takahashi, Akihisa*; Kubo, Makoto*; Ma, H.*; Nakagawa, Akiko*; Yoshida, Yukari*; Isono, Mayu*; Kanai, Tatsuaki*; Ono, Tatsuya*; Furusawa, Yoshiya*; Funayama, Tomoo; et al.
Radiation Research, 182(3), p.338 - 344, 2014/09
Times Cited Count:57 Percentile:90.46(Biology)To clarify whether high-LET radiation inhibits all repair pathways or specifically one repair pathway, studies were designed to examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Embryonic fibroblasts bearing repair gene KO were exposed to X rays, carbon-, iron-, neon- and argon-ion beams. Cell survival was measured with colony-forming assays. The sensitization enhancement ratio (SER) values were calculated using the 10% survival dose of wild-type cells and repair-deficient cells. Cellular radiosensitivity was listed in descending order: double-KO cells NHEJ-KO cells HR-KO cells wild-type cells. Although HR-KO cells had an almost constant SER value, NHEJ-KO cells showed a high-SER value when compared to HR-KO cells, even with increasing LET values. These results suggest that with carbon-ion therapy, targeting NHEJ repair yields higher radiosensitivity than targeting homologous recombination repair.
Mashimo, Izumi*; Otani, Eiji*; Hirao, Naohisa*; Mitsui, Takaya; Masuda, Ryo*; Seto, Makoto*; Sakai, Takeshi*; Takahashi, Suguru*; Nakano, Satoshi*
American Mineralogist, 99(8-9), p.1555 - 1561, 2014/08
Times Cited Count:7 Percentile:23.61(Geochemistry & Geophysics)Isoda, Makoto*; Nakano, Hiroki*; Sakai, Toru
Journal of the Physical Society of Japan, 83(8), p.084710_1 - 084710_7, 2014/08
Times Cited Count:21 Percentile:74.03(Physics, Multidisciplinary)The spin-1/2 Heisenberg antiferromagnet on the Cairo pentagon lattice is investigated by the numerical diagonalization. As a result, it was found that an orthogonal dimer, the disorder, and the ferrimagnetic states appear depending on the ratio of the two exchange interactions.
Nakano, Hiroki*; Isoda, Makoto*; Sakai, Toru
Journal of the Physical Society of Japan, 83(5), p.053702_1 - 053702_4, 2014/04
Times Cited Count:27 Percentile:79.00(Physics, Multidisciplinary)We study the = 1/2 Heisenberg antiferromagnet on the Cairo pentagon lattice by the numerical diagonalization. We tune the ratio of two antiferromagnetic interactions coming from two kinds of in equivalent sites in this lattice, examining the magnetization process; particular attention are focused on the one-third height of the saturation. We find that a quantum phase transition occurs at a specific value of the ratio and that a magnetization plateau appears in the vicinity of the transition.
Komatsu, Mitsuru*; Nishigaki, Makoto*; Seno, Shoji*; Hirata, Yoichi*; Takenobu, Kazuyoshi*; Tagishi, Hirotaka*; Kunimaru, Takanori; Maekawa, Keisuke; Yamamoto, Yoichi; Toida, Masaru*; et al.
JAEA-Research 2012-001, 77 Pages, 2012/09
This research focused on methods of estimating the amounts of groundwater recharge, which are normally required as upper boundary conditions in groundwater flow analyses, based on measurements of infiltrating water in the ground, to systematize the methods and establish systems which are stable and measurable on site over a long time. Regarding developing measurement systems, fiber-optic strain measurement methods that enable multiple-point and long-distance measurement were used for measuring three quantities: suction pressure, soil moisture and volumetric water content rate obtained by applying water absorption swelling material, and each measurement was discussed. The results showed that the fiber-optic soil aquameter has two types of practical application: one for measuring suction pressure (Type I), and the other for measuring volumetric water content rate obtained by applying water absorption swelling material (Type III). Furthermore, by using measurement instruments in actual fields, the validity of the two methods for estimating the rainfall infiltration capacities of shallow-layer soils, that is, estimating the capacities either directly by measurements of soil water or from unsaturated hydraulic conductivities, was confirmed.
Ueda, Yoshio*; Oya, Kaoru*; Ashikawa, Naoko*; Ito, Atsushi*; Ono, Tadayoshi*; Kato, Daiji*; Kawashima, Hisato; Kawamura, Gakushi*; Kenmotsu, Takahiro*; Saito, Seiki*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 88(9), p.484 - 502, 2012/09
no abstracts in English
Sato, Takahiro*; Iwasaki, Atsushi*; Ishibashi, Kazuki*; Okino, Tomoya*; Yamanouchi, Kaoru*; Adachi, Junichi*; Yagishita, Akira*; Yazawa, Hiroki*; Kannari, Fumihiko*; Aoyama, Makoto; et al.
Europhysics News, 42(5), P. 10, 2011/09
The resonant and non-resonant two-photon single ionization processes of He were investigated using intense free electron laser light in the extreme ultraviolet (XUV) region (53.4-61.4 nm) covering the 1s-2p and 1s-3p resonant transitions of He. On the basis of the dependences of the yield of He on the XUV light-field intensity at 53.4, 58.4, 56.0 and 61.4 nm, the absolute values of the two-photon ionization cross sections of He at the four different wavelengths and their dependence on the light-field intensity were determined for the first time.
Sato, Takahiro*; Iwasaki, Atsushi*; Ishibashi, Kazuki*; Okino, Tomoya*; Yamanouchi, Kaoru*; Adachi, Junichi*; Yagishita, Akira*; Yazawa, Hiroki*; Kannari, Fumihiko*; Aoyama, Makoto; et al.
Journal of Physics B; Atomic, Molecular and Optical Physics, 44(16), p.161001_1 - 161001_5, 2011/08
Times Cited Count:36 Percentile:83.23(Optics)The resonant and non-resonant two-photon single ionization processes of He were investigated using intense free electron laser light in the extreme ultraviolet (XUV) region (53.4-61.4 nm) covering the 1s-2p and 1s-3p resonant transitions of He. On the basis of the dependences of the yield of He on the XUV light-field intensity at 53.4, 58.4, 56.0 and 61.4 nm, the absolute values of the two-photon ionization cross sections of He at the four different wavelengths and their dependence on the light-field intensity were determined for the first time.
Natsume, Tomohiro*; Nakano, Makoto*; Harada, Akio; Yamanaka, Atsushi; Kurihara, Ryoichi
Genshiryoku eye, 57(4), p.72 - 76, 2011/04
no abstracts in English
Tonegawa, Takashi*; Okamoto, Kiyomi*; Nakano, Hiroki*; Sakai, Toru; Nomura, Kiyohide*; Kaburagi, Makoto*
Journal of the Physical Society of Japan, 80(4), p.043001_1 - 043001_4, 2011/04
Times Cited Count:37 Percentile:82.17(Physics, Multidisciplinary)Using mainly numerical method, we investigate the ground-state phase diagram of the =2 quantum spin chain with on-site and anisotropies. As a result we found a new phase between the well-known Haldane phase and the large- phase. The precise phase diagram is presented by the level spectroscopy method.
Sasaki, Satoru; Suzuki, Soju; Nakano, Junichi; Takamatsu, Misao; Matoba, Ichiyo*; Nakano, Makoto*; Oketani, Koichiro*; Natsume, Tomohiro*
Genshiryoku eye, 57(2), p.66 - 75, 2011/02
no abstracts in English
Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Okino, Tomoya*; Yamanouchi, Kaoru*; et al.
Optics Express (Internet), 19(1), p.317 - 324, 2011/01
Times Cited Count:96 Percentile:96.39(Optics)The 13th harmonic of a Ti:sapphire (Ti:S) laser in the plateau region was injected as a seeding source to a 250-MeV free-electron-laser (FEL) amplifier. When the amplification conditions were fulfilled, strong enhancement of the radiation intensity by a factor of 650 was observed. The random and uncontrollable spikes, which appeared in the spectra of the Self-Amplified Spontaneous Emission (SASE) based FEL radiation without the seeding source, were found to be suppressed drastically to form to a narrow-band, single peak profile at 61.2 nm. The properties of the seeded FEL radiation were well reproduced by numerical simulations. We discuss the future precept of the seeded FEL scheme to the shorter wavelength region.
Iwamoto, Naoya; Onoda, Shinobu; Hishiki, Shigeomi; Oshima, Takeshi; Murakami, Makoto*; Nakano, Itsuo*; Kawano, Katsuyasu*
Materials Science Forum, 600-603(Part 2), p.1043 - 1046, 2009/00
The 6H-SiC np diodes were fabricated on a p-type substrate. To clarify the radiation resistance of the device performance, the diodes were irradiated with 1MeV-electrons at fluence up to 610/cm and the Charge Collection Efficiencies (CCEs) and diffusion length (L) of minority carriers were evaluated from the evaluation of the Transient Ion Beam Induced Current (TIBIC). The saturated CCE of 93% was obtained for non-electron irradiated diodes, and the value of CCE was kept up to electron fluences of 110/cm, although L decreased to 0.6m from 2.5m by the irradiation. The degradation of CCE was observed at fluences above 510/cm.
Onoda, Shinobu; Iwamoto, Naoya; Murakami, Makoto; Oshima, Takeshi; Hirao, Toshio; Kojima, Kazutoshi*; Kawano, Katsuyasu*; Nakano, Itsuo*
Materials Science Forum, 615-617, p.861 - 864, 2009/00
no abstracts in English
Matsuda, Norihiro; Iwamoto, Yosuke; Harada, Masahide; Teshigawara, Makoto; Meigo, Shinichiro; Maekawa, Fujio; Oguri, Tomomi*; Nakano, Hideo*; Nakao, Noriaki*; Nakane, Yoshihiro; et al.
JAEA-Technology 2008-030, 150 Pages, 2008/03
Radiation Shielding design/safety analysis required for licensing of the high intensity proton accelerator facility J-PARC (Japan Proton Accelerator Research Complex) is in progress, using various high-energy particle transport codes. Shielding benchmark problems, mainly based on experiments, on thick target neutron yield, beam dump geometry, deep penetration and radiation streaming were prepared and analyzed by the shielding design codes, in order to estimate the code's accuracy. The results of analyses show that the calculation results agree with the experiments within a factor of two on the whole.