Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 70

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Hot cell equipment improvement effortsat Analytical Laboratory in Tokai Reprocessing Plant

Ishibashi, Atsushi; Masui, Kenji; Goto, Yuichi; Yamamoto, Masahiko; Taguchi, Shigeo; Ishikawa, Satoshi*; Ishikawa, Tomoya*

Nihon Hozen Gakkai Dai-19-Kai Gakujutsu Koenkai Yoshishu, p.18 - 21, 2023/08

An inner-box typed hot cell for analysis of highly radioactive samples has been operated for about 40 years in Tokai Reprocessing Plant since its installation in 1980. During the operation of analytical hot cell, improvement and upgrades including auxiliary equipment have been performed, in addition to keep the equipment in proper condition through periodic inspections and maintenance. This paper describes about these efforts for analytical hot cell and its results.

Journal Articles

Angular distribution of $$gamma$$ rays from a neutron-induced $$p$$-wave resonance of $$^{132}$$Xe

Okudaira, Takuya*; Tani, Yuika*; Endo, Shunsuke; Doskow, J.*; Fujioka, Hiroyuki*; Hirota, Katsuya*; Kameda, Kento*; Kimura, Atsushi; Kitaguchi, Masaaki*; Luxnat, M.*; et al.

Physical Review C, 107(5), p.054602_1 - 054602_7, 2023/05

 Times Cited Count:0 Percentile:70.47(Physics, Nuclear)

no abstracts in English

Journal Articles

Measurement of the transverse asymmetry of $$gamma$$ rays in the $$^{117}$$Sn($$n,gamma$$)$$^{118}$$Sn reaction

Endo, Shunsuke; Okudaira, Takuya*; Abe, Ryota*; Fujioka, Hiroyuki*; Hirota, Katsuya*; Kimura, Atsushi; Kitaguchi, Masaaki*; Oku, Takayuki; Sakai, Kenji; Shima, Tatsushi*; et al.

Physical Review C, 106(6), p.064601_1 - 064601_7, 2022/12

 Times Cited Count:1 Percentile:54.36(Physics, Nuclear)

no abstracts in English

Journal Articles

Angular distribution of $$gamma$$ rays from the $$p$$-wave resonance of $$^{118}$$Sn

Koga, Jun*; Takada, Shusuke*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Niinomi, Yudai*; Okudaira, Takuya*; et al.

Physical Review C, 105(5), p.054615_1 - 054615_5, 2022/05

 Times Cited Count:2 Percentile:68.81(Physics, Nuclear)

no abstracts in English

Journal Articles

Measurement and evaluation of hydrogen production from mixtures of seawater and zeolite in decontamination of radioactive water

Kumagai, Yuta; Nagaishi, Ryuji; Kimura, Atsushi*; Taguchi, Mitsumasa*; Nishihara, Kenji; Yamagishi, Isao; Ogawa, Toru

Insights Concerning the Fukushima Daiichi Nuclear Accident, Vol.4; Endeavors by Scientists, p.37 - 45, 2021/10

Zeolite adsorbents are to be used for decontamination of radioactive water in Fukushima Dai-ichi Nuclear Power Station. Evaluation of hydrogen production by water radiolysis during decontamination is important for safe operation. Thus hydrogen production from the mixture of zeolite adsorbents and seawater was studied because seawater was urgently used as a coolant for the fuels. The hydrogen yield from the mixture decreased at a high weight fraction of zeolites. However, the measured yield was higher than the yield expected from the direct radiolysis of seawater in the mixture, which would decrease proportional to the weight fraction of seawater. The result suggests that the radiation energy deposited to zeolites was involved in the hydrogen formation. From the results, the hydrogen production rate was evaluated to be 3.6 mL/h per ton of radioactive water before decontamination. After the process, it was evaluated to be 1.5 L/h per ton of waste adsorbents due to the high dose rate.

Journal Articles

Energy-dependent angular distribution of individual $$gamma$$ rays in the $$^{139}$$La($$n, gamma$$)$$^{140}$$La$$^{ast}$$ reaction

Okudaira, Takuya*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Niinomi, Yudai*; Sakai, Kenji; et al.

Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07

 Times Cited Count:3 Percentile:58.42(Physics, Nuclear)

Journal Articles

Development and application of a $$^3$$He neutron spin filter at J-PARC

Okudaira, Takuya; Oku, Takayuki; Ino, Takashi*; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Takahashi, Shingo*; Aizawa, Kazuya; Endo, Hitoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10

 Times Cited Count:9 Percentile:79.84(Instruments & Instrumentation)

Journal Articles

Transverse asymmetry of $$gamma$$ rays from neutron-induced compound states of $$^{140}$$La

Yamamoto, Tomoki*; Okudaira, Takuya; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ino, Takashi*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; et al.

Physical Review C, 101(6), p.064624_1 - 064624_8, 2020/06

 Times Cited Count:8 Percentile:74.44(Physics, Nuclear)

Journal Articles

Measurement of the angular distribution of $$gamma$$-rays after neutron capture by $$^{139}$$La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

Parity violating effects enhanced by up to 10$$^6$$ times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,$$gamma$$) reaction was measured with $$^{139}$$La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized $$^{139}$$La target and a 70% polarized $$^3$$He spin filter whose thickness is 70 atm$$cdot$$cm are needed. Therefore high quality $$^3$$He spin filter is developed in JAEA. The measurement result of the (n,$$gamma$$) reaction at J-PARC and the development status of the $$^3$$He spin filter will be presented.

Journal Articles

Development of the neutron polarizer for the T-violation search using compound nuclei

Okudaira, Takuya; Oku, Takayuki; Sakai, Kenji; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Shinohara, Takenao; Kakurai, Kazuhisa*; Aizawa, Kazuya; Shimizu, Hirohiko*; et al.

Proceedings of Science (Internet), 356, p.029_1 - 029_5, 2019/12

The technology development section carries out the development of the neutron polarization device: $$^{3}$$He Spin Filter. It is often used for the fundamental physics region. In order to explain the matter-dominated universe, a time reversal violation is necessary and searches for new physics are conducted in the world. The T-violation search using a polarized neutron beam is planned at J-PARC. A large $$^{3}$$He spin filter is needed to polarize high energy neutrons for the experiment and is developed in JAEA. Recently, we developed the accurate measurement system to evaluate the polarization of $$^{3}$$He and a vacuum system to make the $$^{3}$$He spin filter, and large $$^{3}$$He spin filters for epi-thermal neutron was made using the system. The current status of the development of the $$^{3}$$He spin filter will be talked.

Journal Articles

New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

 Times Cited Count:13 Percentile:99.28

Journal Articles

Angular distribution of $$gamma$$ rays from neutron-induced compound states of $$^{140}$$La

Okudaira, Takuya*; Takada, Shusuke*; Hirota, Katsuya*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Nagamoto, Kosuke*; Nakao, Taro*; Okada, Anju*; Sakai, Kenji; et al.

Physical Review C, 97(3), p.034622_1 - 034622_15, 2018/03

 Times Cited Count:11 Percentile:71.44(Physics, Nuclear)

Journal Articles

Characterization of germanium detectors for the measurement of the angular distribution of prompt $$gamma$$-rays at the ANNRI in the MLF of the J-PARC

Takada, Shusuke*; Okudaira, Takuya*; Goto, Fumiya*; Hirota, Katsuya*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Nakao, Taro*; Sakai, Kenji; Shimizu, Hirohiko*; et al.

Journal of Instrumentation (Internet), 13(2), p.P02018_1 - P02018_21, 2018/02

 Times Cited Count:6 Percentile:31.36(Instruments & Instrumentation)

Journal Articles

Electronic structure and correlation in $$beta$$-Ti$$_3$$O$$_5$$ and $$lambda$$-Ti$$_3$$O$$_5$$ studied by hard X-ray photoelectron spectroscopy

Kobayashi, Keisuke*; Taguchi, Munetaka*; Kobata, Masaaki; Tanaka, Kenji*; Tokoro, Hiroko*; Daimon, Hiroshi*; Okane, Tetsuo; Yamagami, Hiroshi; Ikenaga, Eiji*; Okoshi, Shinichi*

Physical Review B, 95(8), p.085133_1 - 085133_7, 2017/02

AA2017-0038.pdf:0.98MB

 Times Cited Count:13 Percentile:56.38(Materials Science, Multidisciplinary)

Journal Articles

Tailoring crystallinity and configuration of silica nanotubes by electron irradiation

Taguchi, Tomitsugu; Yamaguchi, Kenji

Nuclear Instruments and Methods in Physics Research B, 350, p.1 - 5, 2015/05

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

SiO$$_{2}$$ nanotubes show potential in applications such as nanoscale electronic and optical devices, bioseparation, biocatalysis, and nanomedicine. As-grown SiO$$_{2}$$ nanotubes in the previous studies always have an amorphous wall, and here we demonstrate the successful synthesis of single-crystal nanotubes for the first time by the heat treatment of SiC nanotubes at 1300 $$^{circ}$$C for 10 h under low-vacuum conditions. According to TEM observations, the single-crystal SiO$$_{2}$$ was $$alpha$$-cristobalite. We also demonstrate that single-crystal SiO$$_{2}$$ nanotubes can be transformed into amorphous SiO$$_{2}$$ nanotubes by electron beam irradiation. Moreover, we synthesized a crystalline/amorphous SiO$$_{2}$$ composite nanotube, in which crystalline and amorphous SiO$$_{2}$$ coexisted in different localized regions. In addition, for biomedical applications such as drug delivery systems, controlling the configuration of the open end, the diameter, and capsulation of SiO$$_{2}$$ nanotubes is crucial. We can also obturate, capsulate, and cut a SiO$$_{2}$$ nanotube, as well as modify the inner diameter of the nanotube at a specific, nanometer-sized region using the focused electron beam irradiation technique.

Journal Articles

Deposition of hydroxyapatite on SiC nanotubes in simulated body fluid

Taguchi, Tomitsugu; Miyazaki, Toshiki*; Iikubo, Satoshi*; Yamaguchi, Kenji

Materials Science & Engineering C, 34, p.29 - 34, 2014/01

 Times Cited Count:9 Percentile:21.09(Materials Science, Biomaterials)

SiC nanotubes can become candidate reinforcement materials for dental and orthopedic implants due to their light weight and excellent mechanical properties. However, it has not been reported about the development of bioactive SiC materials. In this study, hydroxyapatites were found to on SiC nanotubes treated with NaOH and subsequently HCl solution after soaking in simulated body fluid. On the other hand, hydroxyapatites did not deposit on as-received SiC nanotubes, the SiC nanotubes with NH$$_{4}$$OH solution treatment and SiC bulk materials with NaOH and subsequently HCl solution treatment. Therefore, we succeeded in the development of bioactive SiC nanotubes by downsizing SiC materials to nanometer size and treating with NaOH and subsequently HCl solutions for the first time.

Journal Articles

Effect of spacer in microwave oven cavity to heat uniformly Pu/U mixed nitrate solution for producing MOX Fuels

Imai, Suguru*; Taguchi, Kenji*; Kashiwa, Tatsuya*; Kitazawa, Toshihide*; Kato, Yoshiyuki; Segawa, Tomoomi; Suzuki, Masahiro

Denki Gakkai Rombunshi, A, 133(5), p.271 - 272, 2013/05

As a part of the nuclear fuel cycle in Japan, the mixed oxide (MOX) fuels are produced through the microwave heating of the Pu/U mixed nitrate solution obtained from spent fuels. In this work, we investigate the effect of a spacer between the bottom of cavity and solution dish in microwave oven cavity to heat unifomly Pu/U mixed nitrate solution for making MOX fuels. As a result, we show the effectiveness of inserting the spacer for a uniform heating of the solution by evaluating the top-to-bottom ratio.

Journal Articles

Measurement and evaluation of hydrogen production from mixtures of seawater and zeolite in decontamination of radioactive water

Kumagai, Yuta; Nagaishi, Ryuji; Kimura, Atsushi; Taguchi, Mitsumasa; Nishihara, Kenji; Yamagishi, Isao; Ogawa, Toru

Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(4), p.235 - 239, 2011/12

Zeolite adsorbents are to be used for decontamination of radioactive water in Fukushima Dai-ichi Nuclear Power Station. Evaluation of hydrogen production by water radiolysis during decontamination is important for safe operation. Thus hydrogen production from the mixture of zeolite adsorbents and seawater was studied because seawater was urgently used as a coolant for the fuels. The hydrogen yield from the mixture decreased at a high weight fraction of zeolites. However, the measured yield was higher than the yield expected from the direct radiolysis of seawater in the mixture, which would decrease proportional to the weight fraction of seawater. The result suggests that the radiation energy deposited to zeolite is involved in the hydrogen formation. From the results, the hydrogen production rate was evaluated to be 3.6 mL/h per ton of radioactive water before decontamination. After the process, it was evaluated to be 1.5 L/h per ton of waste adsorbents due to the high dose rate.

Journal Articles

Microwave heating of solid Pu/U mixed nitrate medium in cylindrical cavity for nuclear fuel cycle

Imai, Suguru*; Nakajima, Yuki*; Taguchi, Kenji*; Kashiwa, Tatsuya*; Kitazawa, Toshihide*; Suzuki, Masahiro; Segawa, Tomoomi; Fujii, Kanichi

Proceedings of 2011 International Symposium on Antennas and Propagation (ISAP 2011) (USB Flash Drive), 4 Pages, 2011/10

As a part of the nuclear fuel cycle in Japan, the mixed oxide (MOX) fuels are produced through the microwave heating of the Pu/U mixed nitrate solution obtained from spent fuels. This paper investigated the electric power absorption of the solid Pu/U mixed nitrate medium in a cylindrical oven cavity and the effect of the input polarized waves. The numerical simulations have revealed that the incidence of the circularly polarized wave improves the uniformity of the absorbed power of the medium placed in the cylindrical cavity.

Journal Articles

Pulse radiolysis study of ion-species effects on the solvated electron in alkylammonium ionic liquids

Kondo, Takafumi*; Asano, Akira*; Yang, J.*; Norizawa, Kimihiro*; Takahashi, Kenji*; Taguchi, Mitsumasa; Nagaishi, Ryuji; Kato, Ryuji*; Yoshida, Yoichi*

Radiation Physics and Chemistry, 78(12), p.1157 - 1160, 2009/12

 Times Cited Count:28 Percentile:85.96(Chemistry, Physical)

Spectrum and kinetic behavior of solvated electrons (e$$_{sol}$$$$^{-}$$) in alkyl ammonium ionic liquids (ILs), ${it i.e.}$ DEMMA-TFSI, DEMMA-BF4, TMPA-TFSI, PP13-TFSI, P13-TFSI and P14-TFSI were investigated by pulse radiolysis method. The e$$_{sol}$$$$^{-}$$ in the ILs have same absorption peak at 1100 nm with a molar absorption coefficient of 1.5-2.3$$times$$10$$^{4}$$ dm$$^{3}$$mol$$^{-1}$$cm$$^{-1}$$. The reaction rate constant of e$$_{sol}$$$$^{-}$$ with Pyrene (Py) was 1.5-3.5$$times$$10$$^{8}$$ dm$$^{3}$$mol$$^{-1}$$s$$^{-1}$$. These values were about one order of magnitude higher than that of diffusion controlled limit, which was calculated from measured viscosity. The dry electron (e$$_{dry}$$$$^{-}$$) reacts with Py, and its rate constant in DEMMA-TFSI was 7.9$$times$$10$$^{11}$$ dm$$^{3}$$mol$$^{-1}$$s$$^{-1}$$, three orders of magnitude higher than that of the e$$_{sol}$$$$^{-}$$ reactions.

70 (Records 1-20 displayed on this page)