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Journal Articles

Japanese Evaluated Nuclear Data Library version 5; JENDL-5

Iwamoto, Osamu; Iwamoto, Nobuyuki; Kunieda, Satoshi; Minato, Futoshi; Nakayama, Shinsuke; Abe, Yutaka*; Tsubakihara, Kosuke*; Okumura, Shin*; Ishizuka, Chikako*; Yoshida, Tadashi*; et al.

Journal of Nuclear Science and Technology, 60(1), p.1 - 60, 2023/01

 Times Cited Count:64 Percentile:99.99(Nuclear Science & Technology)

Journal Articles

High-spin states in $$^{35}$$S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.

Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03

 Times Cited Count:4 Percentile:57.13(Physics, Nuclear)

Journal Articles

Current situations and discussions in Japan in relation to the new occupational equivalent dose limit for the lens of the eye

Yokoyama, Sumi*; Hamada, Nobuyuki*; Hayashida, Toshiyuki*; Tsujimura, Norio; Tatsuzaki, Hideo*; Kurosawa, Tadahiro*; Nabatame, Kuniaki*; Oguchi, Hiroyuki*; Ono, Kazuko*; Kawaura, Chiyo*; et al.

Journal of Radiological Protection, 37(3), p.659 - 683, 2017/09

 Times Cited Count:15 Percentile:82.15(Environmental Sciences)

Since the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye in 2011, there have been extensive discussions in various countries. This paper reviews the current situations in radiation protection of the ocular lens and the discussions on the potential impact of the new lens dose limit in Japan. Topics include historical changes to the lens dose limit, the current situations in occupational lens exposures (e.g., in medical workers, nuclear workers, and Fukushima nuclear power plant workers) and measurements, and the current status of biological studies and epidemiological studies on radiation cataracts. Our focus is on the situations in Japan, but we believe such information sharing will be useful in many other countries.

Journal Articles

Improvement of symbiotic performance of ${it Sinorhizobium}$ with ${it Vigna marina}$ under high salt conditions using the ion beam mutation breeding

Maruyama, Yudai*; Takeda, Kiyoko*; Tomooka, Norihiko*; Sato, Katsuya; Ono, Yutaka; Yokoyama, Tadashi*

JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 99, 2016/02

Journal Articles

Addendum report of the JHPS expert committee on radiation protection of the lens of the eye, 2; When and how should the dosimetry of beta $$H_{rm p}$$(3) be made?

Akahane, Keiichi*; Iimoto, Takeshi*; Ichiji, Takeshi*; Iwai, Satoshi*; Oguchi, Hiroyuki*; Ono, Kazuko*; Kawaura, Chiyo*; Kurosawa, Tadahiro*; Tatsuzaki, Hideo*; Tsujimura, Norio; et al.

Hoken Butsuri, 50(4), p.257 - 261, 2015/12

In a mixed field of photon and beta radiations, the same dose assigned to skin is normally assigned to the dose to the lens of the eye as a conservative estimate of H$$_{p}$$(3). In exceptional cases that a very high beta dose might be imparted of the same order with the dose limit, however, the conservatively biased dose must be too limiting, and thereby an accurate estimate of beta $$H_{rm p}$$(3) is desirable. This article presents a practical proposal of when and how the dosimetry of beta $$H_{rm p}$$(3) should be made.

Journal Articles

Superdeformation in $$^{35}$$S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Kobayashi, Motoki*; Kisamori, Keiichi*; Takaki, Motonobu*; Miya, Hiroyuki*; Ota, Shinsuke*; Michimasa, Shinichiro*; Shimoura, Susumu*; et al.

JPS Conference Proceedings (Internet), 6, p.030005_1 - 030005_4, 2015/06

Journal Articles

Development of prediction technology of two-phase flow dynamics under earthquake acceleration, 16; Experimental and numerical study of pressure fluctuation effects on bubble motion

Kato, Yuki; Yoshida, Hiroyuki; Yokoyama, Ryotaro*; Kanagawa, Tetsuya*; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 8 Pages, 2015/05

Journal Articles

Genome analysis of the high temperature tolerant mutant of ${it Bradyrhizobium japonicum}$ USDA110 generated by ion-beam irradiation

Takeda, Kiyoko*; Sato, Katsuya; Narumi, Issey*; Ono, Yutaka; Otsu, Naoko*; Yokoyama, Tadashi*

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 120, 2015/03

Journal Articles

Interim report of the JHPS expert committee on radiation protection of the lens of the eye, 2; The Dosimetry method for the lens of the eye of workers in Japan

Akahane, Keiichi*; Iimoto, Takeshi*; Ichiji, Takeshi*; Iwai, Satoshi*; Oguchi, Hiroyuki*; Ono, Kazuko*; Kawaura, Chiyo*; Tatsuzaki, Hideo*; Tsujimura, Norio; Hamada, Nobuyuki*; et al.

Hoken Butsuri, 49(3), p.153 - 156, 2014/09

A brief review is given of the history and methodology of external dosimetry for the lens of the eye. Under the 1989 revision to domestic radiological protection regulations, the concept on the effective dose equivalent and the dose limit to the lens of the eye (150 mSv/y) both introduced in ICRP 1977 recommendations has changed nationwide the external monitoring methodology in non-uniform exposure situations to the trunk of a radiological worker. In such situations, often created by the presence of a protective apron, the worker is required to use at least two personal dosemeters, one worn on the trunk under the apron and the other, typically, at the collar over the apron. The latter dosemeter serves the dual purpose of providing the dose profile across the trunk for improved effective dose equivalent assessment and of estimating the dose to lens of the eye. The greater or appropriate value between $$H_{rm p}$$(10) and $$H_{rm p}$$(0.07), given by the dosemeter, is generally used as a surrogate of $$H_{rm p}$$(3).

Journal Articles

Long term integrity of overpack closure weld for HLW geological disposal, 2; Corrosion properties under anaerobic conditions

Kobayashi, Masato*; Yokoyama, Yutaka*; Takahashi, Rieko*; Asano, Hidekazu*; Taniguchi, Naoki; Naito, Morimasa

Corrosion Engineering, Science and Technology, 46(2), p.212 - 216, 2011/04

 Times Cited Count:4 Percentile:29.02(Materials Science, Multidisciplinary)

The corrosion behaviour of a carbon steel weld joint under anaerobic conditions was investigated to estimate the long-term integrity of the carbon steel overpack. The weld specimens in this study were produced using three welding methods: GTAW, GMAW and EBW. General corrosion was observed for each immersion specimen and the weld joint corrosion rate was the same as or less than that of the base metal. The hydrogen concentration absorbed during immersion testing was less than 2.48$$times$$10$$^{-5}$$ mol kg[Fe]$$^{-1}$$(0.05 ppm) after three years, a value regarded as having little influence on hydrogen embrittlement. The susceptibility to hydrogen embrittlement was highest in the base metal, suggesting that there was little adverse effect on the weld joint from welding. The welded carbon steel overpack is assumed to maintain its resistance to corrosion as a disposal container for the expected lifetime under anaerobic underground conditions.

Journal Articles

Dynamics of ion internal transport barrier in LHD heliotron and JT-60U tokamak plasmas

Ida, Katsumi*; Sakamoto, Yoshiteru; Yoshinuma, Mikiro*; Takenaga, Hidenobu; Nagaoka, Kenichi*; Hayashi, Nobuhiko; Oyama, Naoyuki; Osakabe, Masaki*; Yokoyama, Masayuki*; Funaba, Hisamichi*; et al.

Nuclear Fusion, 49(9), p.095024_1 - 095024_9, 2009/09

 Times Cited Count:29 Percentile:72.01(Physics, Fluids & Plasmas)

Dynamics of ion internal transport barrier (ITB) formation and impurity transport both in the Large Helical Device (LHD) heliotron and JT-60U tokamak are described. Significant differences between heliotron and tokamak plasmas are observed. The location of the ITB moves outward during the ITB formation regardless of the sign of magnetic shear in JT-60U and the ITB becomes more localized in the plasma with negative magnetic shear. In LHD, the low Te/Ti ratio ($$<$$ 1) of the target plasma for the high power heating is found to be necessary condition to achieve the ITB plasma and the ITB location tends to expand outward or inward depending on the condition of the target plasmas. Associated with the formation of ITB, the carbon density tends to be peaked due to inward convection in JT-60U, while the carbon density becomes hollow due to outward convection in LHD. The outward convection observed in LHD contradicts the prediction by neoclassical theory.

Journal Articles

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution

Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.

Radiochimica Acta, 97(2), p.83 - 89, 2009/02

 Times Cited Count:20 Percentile:77.78(Chemistry, Inorganic & Nuclear)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F, 5n)$$^{262}$$Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K$$_{d}$$) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta $$approx$$ Nb $$>$$ Db $$geq$$ Pa.

JAEA Reports

Alpha radioactivity measurement technology with ionized air type measurement; Applicability evaluation to verification of the clearance level

Mita, Yutaka; Matsumura, Toshihiro; Yokoyama, Kaoru; Sugitsue, Noritake

JAEA-Technology 2008-061, 35 Pages, 2008/10

JAEA-Technology-2008-061.pdf:3.87MB

In Ningyo-toge Environmental Engineering Center. The equipments and radioactive waste which were contaminated with uranium are generated so much in future dismantling stage. In our plan, some of equipments and radioactive waste are decontamination to a clearance level, and cut down on decommission and disposal expense. This plan needs the alpha-rays measurement technology of the very low level. We think that ionized Air transfer measurement technology is promising as of clearance verification technology. The ionized Air transfer measurement technology applied to the Ionized Air Type Measurement can measure alpha radioactivity of a very low level. Moreover, as compared with a direct survey, there is the merit which can be measured in a short time. However ionized Air transfer measurement technology is new technology. Therefore, there is almost no measurement track record. Furthermore, the date about the influence of a background, a detection limit, measurement performance, and reliability is insufficient. So, this measurement test estimated applicability as clearance level verification of an Ionized Air Type Measurement.

JAEA Reports

Study on the corrosion assessment of overpack welds, 4 (Joint research)

Yokoyama, Yutaka*; Mitsui, Hiroyuki*; Takahashi, Rieko; Taniguchi, Naoki; Asano, Hidekazu*; Naito, Morimasa; Yui, Mikazu

JAEA-Research 2008-072, 232 Pages, 2008/10

JAEA-Research-2008-072.pdf:45.2MB

It is possible that the corrosion resistance at the overpack welds is different from that at base metal due to the differences of material properties. In this study, corrosion behavior of welded joint for carbon steel was compared with base metal using the specimens taken from welded joint model fabricated by TIG (Tungsten Arc Welding, GTAW), MAG (Gas Metal Arc Welding, GMAW) and EBW (Electron Beam Welding) respectively. The results of these corrosion tests indicated that the corrosion resistance to general corrosion, pitting corrosion and crevice corrosion at welded metal of TIG and MAG was inferior to base metal. No deterioration of corrosion resistance was observed in any corrosion modes for EBW, which does not need filler material. Neither the base metals nor the welds is not susceptible to SCC under the carbonate concentration near that of the disposal environment.

Journal Articles

Experimental investigation of particle pinch associated with turbulence in LHD heliotron and JT-60U tokamak plasmas

Tanaka, Kenji*; Takenaga, Hidenobu; Muraoka, Katsunori*; Michael, C.*; Vyacheslavov, L. N.*; Yokoyama, Masayuki*; Yamada, Hiroshi*; Oyama, Naoyuki; Urano, Hajime; Kamada, Yutaka; et al.

Proceedings of 22nd IAEA Fusion Energy Conference (FEC 2008) (CD-ROM), 8 Pages, 2008/10

Comparative studies were carried out in LHD heliotron and JT-60U tokamak plasmas to elucidate the most essential parameter(s) for control of density profiles in toroidal systems. A difference in the collisionality dependence was found between the two devices. In LHD, the density peaking factor decreased with decrease of the collisionality at the magnetic axis position (R$$_{rm au}$$) 3.6 m, while the density peaking factor gradually increased with a decreased of collisionality at R$$_{rm au}$$ = 3.5 m. On the other hand, in JT-60U, the density peaking factor clearly increased with a decrease of the collisionality. The difference in the collisionality dependence between R$$_{rm au}$$ = 3.5 and R$$_{rm au}$$ = 3.6 m is likely due to the contribution of the anomalous transport. At R$$_{rm au}$$ = 3.5 m, larger anomalous transport caused a similar collisionality dependence. Change of the fluctuation property was observed with different density profiles in the plasma core region on both devices. In JT-60U, the increase of the radial coherence was observed with higher density peaking profile suggesting enhanced diffusion and inward directed pinch. For a magnetic axis positions (R$$_{rm au}$$) at 3.6 m in LHD, the increase of the fluctuation power with an increase in P$$_{rm NB}$$ was observed for a hollow density profile suggesting an increase on diffusion due to anomalous processes. Change of density profiles from peaked to hollow indicates change in the convection direction. This is due to increase in neoclassical processes. The reduction of the density peaking factor with increase of P$$_{rm NB}$$ in LHD is partly due to the neoclassical effect and partly due to the anomalous effect.

Journal Articles

Comparisons of density profiles in JT-60U tokamak and LHD helical plasmas with low collisionality

Takenaga, Hidenobu; Tanaka, Kenji*; Muraoka, Katsunori*; Urano, Hajime; Oyama, Naoyuki; Kamada, Yutaka; Yokoyama, Masayuki*; Yamada, Hiroshi*; Tokuzawa, Tokihiko*; Yamada, Ichihiro*

Nuclear Fusion, 48(7), p.075004_1 - 075004_11, 2008/07

 Times Cited Count:32 Percentile:75.35(Physics, Fluids & Plasmas)

In order to understand particle transport systematically in toroidal plasmas, electron density profiles were compared in JT-60U tokamak and LHD helical plasmas with low collisionality. Peakedness of density profiles increased with decreasing collisionality in ELMy H-mode plasmas of JT-60U, when the collisionality at half the minor radius was in the collisionless regime. Collisionality dependence of density profiles in LHD plasmas was similar to that in JT-60U plasmas in the same collisionality regime, when neoclassical transport was suppressed by geometrical optimization. On the other hand, in the LHD plasmas having relatively larger neoclassical transport than that in the above case, peakedness of density profiles decreased with decreasing collisionality. Neoclassical transport enhanced by the non-axisymmetric effect significantly affected density profiles with low collisionality in LHD plasmas. Density profiles in LHD plasmas tended to approach those in JT-60U, which are dominated by anomalous transport, as the contribution of neoclassical transport was reduced.

Journal Articles

Selective transition to the closely-lying states Cs(7$$D$$$$_{3/2}$$) and Cs(7$$D$$$$_{5/2}$$) by femtosecond laser pulses

Yamada, Hidetaka; Yokoyama, Keiichi; Teranishi, Yoshiaki*; Sugita, Akihiro; Shirai, Toshizo*; Aoyama, Makoto; Akahane, Yutaka; Inoue, Norihiro*; Ueda, Hideki*; Yamakawa, Koichi; et al.

Physical Review A, 72(6), p.063404_1 - 063404_5, 2005/12

 Times Cited Count:6 Percentile:31.21(Optics)

A demonstration of coherent quantum control for ultrafast precise selection of closely-lying states is reported. A phase-locked pair of femtosecond laser pulses is generated through a pulse shaper to excite the ground-state cesium atom to the Cs(7$$D$$$$_{3/2}$$) and Cs(7$$D$$$$_{5/2}$$) states by two-photon absorption. The excited state population is measured by detecting fluorescence from each spin-orbit state. By controlling the phase-difference of the pulse pair, an ultrafast precise selection is accomplished. The contrast ratio of the maximal to minimal selection ratio exceeds 10$$^3$$ with the delay less than 400 fs.

Journal Articles

Optimal control of ultrafast selection

Yokoyama, Keiichi; Teranishi, Yoshiaki; Toya, Yukio; Shirai, Toshizo; Fukuda, Yuji; Aoyama, Makoto; Akahane, Yutaka; Inoue, Norihiro*; Ueda, Hideki; Yamakawa, Koichi; et al.

Journal of Chemical Physics, 120(20), p.9446 - 9449, 2004/05

 Times Cited Count:6 Percentile:18.77(Chemistry, Physical)

Optimal laser control for ultrafast selection of closely-lying excited states, whose energy separation is smaller than the laser bandwidth, is reported on the two-photon transition of atomic cesium; Cs(6S $$rightarrow$$ 7D$$_{J}$$, J = 5/2 and 3/2). Selective excitation was carried out by pulse shaping of ultrashort laser pulses which were adaptively modulated in a closed-loop learning system handling eight parameters representing the electric field. Two-color fluorescence from the respective excited states was monitored to measure the selectivity. The fitness used in the learning algorithm was evaluated from the ratio of the fluorescence yield. After fifty generations, a pair of nearly transform-limitted pulses were obtained as an optimal pulse shape, proving the effectiveness of "Ramsey fringes" mechanism. The contrast of the selection ratio was improved by $$sim$$ 30 % from the simple "Ramsey fringes" experiment.

Journal Articles

Fluoride complexation of element 104, rutherfordium

Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Nishinaka, Ichiro; Hirata, Masaru; Yaita, Tsuyoshi; Ichikawa, Shinichi; Nagame, Yuichiro; et al.

Journal of the American Chemical Society, 126(16), p.5219 - 5224, 2004/04

 Times Cited Count:43 Percentile:72.51(Chemistry, Multidisciplinary)

Fluoride complexation of element 104, rutherfordium (Rf), produced in the $$^{248}$$Cm($$^{18}$$O,5n)$$^{261}$$Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchangechromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the $$^{18}$$O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effect on the fluoride complexation of Rf.

JAEA Reports

Development of fabrication technologies for ITER in-vessel components

Kuroda, Toshimasa*; Sato, Kazuyoshi; Akiba, Masato; Ezato, Koichiro; Enoeda, Mikio; Osaki, Toshio*; Kosaku, Yasuo; Sato, Satoshi; Sato, Shinichi*; Suzuki, Satoshi*; et al.

JAERI-Tech 2002-044, 25 Pages, 2002/03

JAERI-Tech-2002-044.pdf:2.68MB

no abstracts in English

45 (Records 1-20 displayed on this page)