Refine your search:     
Report No.
Search Results: Records 1-20 displayed on this page of 143

Presentation/Publication Type

Initialising ...


Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...


Initialising ...


Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Measurements of intensity of produced light in water during irradiations of electron beams with energies above and below the Cerenkov-light threshold

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(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.

JAEA Reports

Quantitative analysis method for radiation distribution in high radiation environment by gamma-ray image spectroscopy (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*

JAEA-Review 2019-036, 65 Pages, 2020/03


JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Quantitative Analysis Method for Radiation Distribution in High Radiation Environment by Gamma-ray Image Spectroscopy". Electron-tracking Compton camera (ETCC) has been developed originally for nuclear gamma-ray astronomy, and also applied to medical use as a technology that greatly improves the resolution of conventional Compton camera by measuring three-dimensional tracking of electrons using a gaseous 3-dimensional position detector (so called Time Projection Chamber) in the first stage. In the present study, based on the ETCC that has been developed for medical use, we produce a prototype of light weight ETCC with the emphasis on the operability at the site, and evaluate its practicability by field tests.

Journal Articles

1 MeV, ampere class accelerator R&D for ITER

Inoue, Takashi; Kashiwagi, Mieko; Taniguchi, Masaki; Dairaku, Masayuki; Hanada, Masaya; Watanabe, Kazuhiro; Sakamoto, Keishi

Nuclear Fusion, 46(6), p.S379 - S385, 2006/06

 Times Cited Count:35 Percentile:74.69(Physics, Fluids & Plasmas)

The JAERI MeV accelerator has been designed extrapolating vacuum insulation design guidelines (the clump theory and Paschen law) to Mega Volt and long vacuum gap. Reduction of electric field concentration at triple junction by a large stress ring was effective to prevent flashover along insulator surface. By the vacuum insulation technology above, the accelerator sustained 1 MV for 8,500 s continuously. Strong enhancement of negative ion surface production has been attained by stopping vacuum leaks due to SF$$_{6}$$ permeation through Viton O rings and a damage of port by backstream ions, followed by increase of the H$$^{-}$$ ion current density without saturation. Operating the KAMABOKO source with high power arc discharge ($$leq$$ 40 kW), H$$^{-}$$ ion beams of 146 A/m$$^{2}$$ (total ion current: 0.2 A) have been obtained stably at the beam energy of 836 keV (pulse length: $$geq$$ 0.2 s). Bremsstrahlung generation in the accelerator is also estimated from EGS4 analysis, and then discussion on the breakdown possibility follows.

Journal Articles

Minor actinide neutron capture cross-section measurements with a 4$$pi$$ Ge spectrometer

Koizumi, Mitsuo; Osa, Akihiko; Toh, Yosuke; Kimura, Atsushi; Mizumoto, Motoharu; Oshima, Masumi; Igashira, Masayuki*; Osaki, Toshiro*; Harada, Hideo*; Furutaka, Kazuyoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 562(2), p.767 - 770, 2006/06

 Times Cited Count:6 Percentile:43.87(Instruments & Instrumentation)

In order to measure the neutron capture cross section of minor actinides, we have proposed the use of a 4$$pi$$ Ge spectrometer. A Time-of-Flight neutron beam line for the experiment has been constructed at the KURRI electron LINAC. The assembling of the 4$$pi$$ Ge spectrometer is in progress. We are also developing a new data acquisition system based on a digital processing technique.

Journal Articles

Study of radiation-induced primary process by ion pulse radiolysis

Yoshida, Yoichi*; Yang, J.*; Kondo, Takafumi*; Seki, Shuhei*; Kozawa, Takahiro*; Tagawa, Seiichi*; Shibata, Hiromi*; Taguchi, Mitsumasa; Kojima, Takuji; Namba, Hideki

JAEA-Review 2005-001, TIARA Annual Report 2004, p.183 - 185, 2006/01

A heavy-ion-pulse radiolysis technology was developed using a single-photon-counting system. In the system, the ion beam was injected a thin scintillator before irradiating the sample. The light emitted from the scintillator by the ion irradiation was used as analyzing source to detect the absorption of primary species in water. Measurement of time-dependent absorption of hydrated electrons in water was achieved using the system, which demonstrates the usefulness of this technique.

Journal Articles

Chain terminations in the decomposition reactions of chloroethylenes in air through the deposition of alkylperoxy radicals on the wall of an irradiation vessel

Hakoda, Teruyuki; Kojima, Takuji

Radiation Physics and Chemistry, 74(5), p.302 - 309, 2005/12

 Times Cited Count:0 Percentile:0.01(Chemistry, Physical)

no abstracts in English

Journal Articles

Decomposition behavior of PCDD/F isomers in incinerator gases under electron-beam irradiation

Hirota, Koichi; Kojima, Takuji

Bulletin of the Chemical Society of Japan, 78(9), p.1685 - 1690, 2005/09

 Times Cited Count:7 Percentile:31.81(Chemistry, Multidisciplinary)

Decomposition behavior under electron-beam irradiation was examined for polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) isomers in incinerator gases. Significant decomposition was obtained for all PCDD isomers over the investigated absorbed doses, which was resulted from oxidation reactions with OH radicals yielded by electron-beam irradiation. In the case of PCDFs, specific isomers having symmetrical structures such as 1, 2, 8, 9-, 2, 3, 7, 8-, and 3, 4, 6, 7-TeCDFs were yielded through the dechlorination of PeCDF isomers. Thermal electrons probably played a role in the dechlorination of PeCDF isomers.

Journal Articles

Oxidation reaction kinetics on Ti(0001) surface studied by real-time photoelectron spectroscopy

Takakuwa, Yuji*; Ogawa, Shuichi*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden

Shokubai, 47(5), p.352 - 357, 2005/08

Oxidation reactions of Ti(0001) surfaces were monitored by real-time photoelectron spectroscopy with high brilliant synchrotron radiation and He-I resonance line. An oxygen adsorption model and ultra-thin oxide layers formation processes were reviewed on the basis of time evolutions of the adsorbed oxygen amount, oxidation states, electronic states and the work function, which were obtained from photoelectron spectra for Ti 2p and O 1s core levels as well as the valence band.

Journal Articles

Electron beam-induced fries rearrangement of sulfonamide and sulfonate crystals

Kato, Jun*; Maekawa, Yasunari; Yoshida, Masaru

Chemistry Letters, 34(2), p.266 - 267, 2005/02

 Times Cited Count:12 Percentile:43.1(Chemistry, Multidisciplinary)

We have investigated the useful EB induced reactions of sulfonamide and sulfonate derivatives in the crystalline state. In this letter, we found that the EB sensitivity of sulfonic acid derivatives in the crystalline tate was much higher than that of the corresponding carboxylic acid derivatives, which was distinct from the results using other energy sources, to give Fries rearrangement products. It is notable that these reactions are solvent-free and are accompanied by the transformation of amide and ester linkages to hydrophilic aniline and phenol groups; especially, an acidic sulfonamide can be converted to the corresponding basic aniline derivatives. These new EB induced transformations can significantly contribute to designing new materials for EB lithography as well as nanoscopic architectures.

Journal Articles

Experimental verification of velocity bunching via shot-by-shot measurement at S-band photoinjector and linac

Iijima, Hokuto; Uesaka, Mitsuru*; Sakamoto, Fumito*; Ueda, Toru*; Kumagai, Noritaka*; Serafini, L.*

Japanese Journal of Applied Physics, Part 1, 44(7A), p.5249 - 5253, 2005/01

 Times Cited Count:8 Percentile:32.22(Physics, Applied)

We represent an experimental verification of a bunch compression method named "velocity bunching". The velocity bunching based on the rectilinear compression uses a traveling wave accelerating tube as a compressor. The experiment was performed by an S-band photoinjector and a linac at Nuclear Engineering Research Laboratory, University of Tokyo. The shot-by-shot bunch length was measured to be 0.5 $$pm$$ 0.1 ps (rms) in average by the femtosecond streak camera for a bunch charge of 1 nC. The experimental result is in good agreement with PARMELA simulations.

Journal Articles

Suppression of electron scattering by the longitudinal components of tightly focused laser fields

Masuda, Shinichi; Kando, Masaki; Kotaki, Hideyuki; Nakajima, Kazuhisa

Physics of Plasmas, 12(1), p.013102_1 - 013102_6, 2005/01

 Times Cited Count:22 Percentile:58.2(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Gas purification technology using electron beams

Kojima, Takuji

Shinku, 47(11), p.789 - 795, 2004/11

When flue gas/off gas is irradiated by EB, many free radicals such as OH and active oxygen atom are formed from major components of air: namely nitrogen, oxygen, water and carbon dioxide ecules. The similer reaction can be achieved using UV light and plasma-discharging, but ionizing radiations produce such free radicals at higher density. Such radiation-induced radicals react efficiently with air pollutants, SOx and NOx in coal/oil combustion flue gas at thermal power plants, dioxins in waste incineration flue gas and volatile organic compounds (VOC) even in very low concentration and decompose them into non-toxic substances or change them to removable substances. R & D on EB treatment of flue gas/off gas done in JAERI on the basis of this principle process, as an example, is described in the present paper.

Journal Articles

Structure of sub-monolayered silicon carbide films

Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Nath, K. G.

Applied Surface Science, 237(1-4), p.176 - 180, 2004/10

 Times Cited Count:7 Percentile:44.02(Chemistry, Physical)

no abstracts in English

Journal Articles

Electron-beam-induced fries rearrangement and oxidation reactions of sulfonic acid esters in crystalline state

Yuasa, Kanako; Enomoto, Kazuyuki*; Maekawa, Yasunari; Kato, Jun*; Yamashita, Takashi*; Yoshida, Masaru

Journal of Photopolymer Science and Technology, 17(1), p.21 - 28, 2004/07

 Times Cited Count:9 Percentile:31.15(Polymer Science)

The electron beam (EB)-induced reactions of arylsulfonic acid esters, phenyl p-toluenesulfonate (1a), phenyl benzenesulfonate (1b), and phenyl 1-naphthalenesulfonate (1c), were examined in the balk state. The EB irradiation of 1a afforded the Fries rearrangement products, o- and p-hydroxyphenyl p-tolylsulfones (2a and 3a), phenol (5), and the oxidation product of 2a, o,p-dihydroxyphenyl p-tolylsulfone (4a), which has not been observed in photolysis. The irradiation of 1b, which is liquid at room temperature, gave Fries products, 5, and the oxidation product, o,p-dihydroxyphenyl phenylsulfone. On the other hand, the EB-induced reaction of 1c proceeded with the lowest reactivity through crystal to crystal transformation to afford Fries products and 5, but not oxidation product. The mechanistic study reveals that oxidation product 4a generated by the oxidation reaction of ortho-Fries product 2a but not para-isomer 3a with an active oxidant, which should result from the decomposition of 1a.

Journal Articles

Electron-beam induced reactions of sulfonium salts in a crystalline state

Enomoto, Kazuyuki*; Maekawa, Yasunari; Moon, S.; Shimoyama, Junji*; Goto, Kazuyuki*; Narita, Tadashi*; Yoshida, Masaru

Journal of Photopolymer Science and Technology, 17(1), p.41 - 44, 2004/06

 Times Cited Count:2 Percentile:9.04(Polymer Science)

The Electron beams (EB)-induced reactions of triphenylsulfonium methanesulfonate (1) in the crystalline state gave benzene-substituted product, biphenylsulfonium methanesulfonate (2), which has not been observed by either photolysis. In this paper, the EB-induced reactions of triphenylsulfonium salt derivatives, which possesses aromatic/aliphatic counter anions, have been examined. The anionic moiety of sulfonium salts has practically little effect on the formation of biphenyl salt 2 as well as the other products. The consumption rates of the sulfonium salts containing aromatic counter anions are somewhat smaller in a crystalline state and about two times larger than those of the salts with aliphatic counter anions. The greater decomposition rates of the sulfonium salts with aromatic counter anions than those of aliphatic counter anions in an amorphous state are elucidated by lower ionization potential of the salts with aromatic counter anions such as tosyl and naphthyl groups than those with aliphatic counter anions.

Journal Articles

Purification technology for flue/off gases using electron beams

Kojima, Takuji

Shokubai, 46(3), p.248 - 253, 2004/04

The present paper describes research and development on purification technology using electron beams for flue/odd gases containing pollutants: removal of sulfate oxide and nitrogen oxide from flue gases of coal/oil combustion power plants, decomposition of dioxins in waste incineration flue gas, and decomposition/removal of toxic volatile organic compounds from off gas.

Journal Articles

Application of electron beams for the treatment of VOC streams

Hirota, Koichi; Sakai, Hiroki*; Washio, Masakazu*; Kojima, Takuji

Industrial & Engineering Chemistry Research, 43(5), p.1185 - 1191, 2004/03

 Times Cited Count:46 Percentile:79.53(Engineering, Chemical)

Twenty volatile organic compounds (VOCs) were irradiated with electron beams in laboratory scale to obtain an electron-beam energy required for a 90% treatment. The experiments showed that the energy was related with the chemical structure and roughly estimated from rate constants for reactions with OH radicals. The cost analysis revealed that the unification of a self-shielding electron accelerator with a reactor could reduce the capital cost for an electron-beam system. Electron-beam technology is a promising method for the treatment of VOCs.

Journal Articles

Application of electron beam for the reduction of PCDD/F emission from Municipal solid waste incinerators

Hirota, Koichi; Hakoda, Teruyuki; Taguchi, Mitsumasa; Takigami, Machiko; Kim, H.; Kojima, Takuji

Environmental Science & Technology, 37(14), p.3164 - 3170, 2003/07

 Times Cited Count:43 Percentile:65.56(Engineering, Environmental)

The electron-beam technology was applied to reduce polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in flue gases from the municipal solid waste incinerator (MSWI) at a temperature of 200$$^{circ}$$C. More than 90% of PCDD/Fs in a flue gas of 1000 m$$^{3}$$N/h was decomposed at a dose of 14 kGy. The decomposition of PCDD/Fs was probably initiated through reactions with OH radicals, followed by the dissociation of ether bond (-C-O-C-), the cleavage of aromatic rings, and dichlorination. The dechlorination of the higher dechlorinated PCDF homologues produced the lower chlorinated ones, which led to lower decomposition efficiency of PCDF than that of PCDD.

Journal Articles

Electron beam technologies for control of flue gases/wastewaters and their applications

Kojima, Takuji

Oyo Butsuri, 72(4), p.405 - 414, 2003/04

The advanced technologies are required to control pollutants e.g. dioxins in gas or water at extremely low concentration. The present paper introduces typical basic studies, developments of control technologies, and example of their industrial applications of electron beam technology having the features of oxidation, decomposition and detoxifying of such pollutants even at low concentration. It covers removal of SOx and NOx from coal-combustion flue gas, decomposition of gaseous volatile organic compound in off gas and dioxins in incineration flue-gas, purification of tap and wastewaters, and treatment of sewage/sludge.

Journal Articles

Development of silicon carbide micro-tube from precursor polymer by radiation oxidation

Sugimoto, Masaki; Idesaki, Akira; Tanaka, Shigeru; Okamura, Kiyohito*

Key Engineering Materials, 247, p.133 - 136, 2003/00

no abstracts in English

143 (Records 1-20 displayed on this page)