Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 39

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

JAEA Reports

Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; High Energy Accelerator Research Organization*

JAEA-Review 2021-042, 115 Pages, 2022/01

JAEA-Review-2021-042.pdf:5.18MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). 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 "Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies" conducted from FY2018 to FY2020. Since the final year of this proposal was FY2020, the results for three fiscal years were summarized. The present study aims to in-situ measure and analyze the distribution status and criticality of flooded fuel debris. For this purpose, we construct a neutron measurement system by developing compact diamond neutron sensor and integrated circuit whose radiation resistance was improved by circuit design. Along with the multi-phased array sonar and the acoustic sub-bottom profiling (SBP) system, the neutron measurement system will be installed in the ROV (developed by

JAEA Reports

Technology development of diamond-base neutron sensors and radiation-resistive integrated-circuits for shielding-free criticality approach monitoring system (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; High Energy Accelerator Research Organization*

JAEA-Review 2021-038, 65 Pages, 2022/01

JAEA-Review-2021-038.pdf:4.42MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). 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 FY2020, this report summarizes the research results of the "Technology development of diamond-base neutron sensors and radiation-resistive integrated-circuits for shielding-free criticality approach monitoring system" conducted in FY2020. The present study aims to develop key components of neutron detection system without a radiation shield for a criticality approach monitoring system. It is required high neutron detection efficiency for a few cps/nv under high gamma ray radiation environment (i.e. 1 kGy/h maximum) and compact-light-weight to fit constraints of the penetration size and the payload. In order to develop the monitoring system, the project aims to design and evaluate neutron detection devices based on diamond sensors and a high radiation resistive signal-processi

JAEA Reports

Development of radiation hardened diamond image sensing devices (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Advanced Industrial Science and Technology*

JAEA-Review 2021-026, 47 Pages, 2021/11

JAEA-Review-2021-026.pdf:2.16MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). 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 FY2019, this report summarizes the research results of the "Development of radiation hardened diamond image sensing devices" conducted in FY2020. The research objective of this project is to develop image sensing devices which work under the high radiation condition. The devices will be realized using radiation hardened diamond semiconductor devices as charge transfer devices and photodetectors. The research project has mainly two targets such as to confirm charge coupled devices operation on diamond unipolar devices and to characterize photo conductivity of diamond detectors.

JAEA Reports

Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; High Energy Accelerator Research Organization*

JAEA-Review 2020-058, 101 Pages, 2021/02

JAEA-Review-2020-058.pdf:5.58MB

JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2018, this report summarizes the research results of the "Research and Development of Radiation-resistant Sensor for Fuel Debris by Integrating Advanced Measurement Technologies" conducted in FY2019.

JAEA Reports

Development of radiation hard diamond image sensing devices (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Advanced Industrial Science and Technology*

JAEA-Review 2020-027, 27 Pages, 2021/01

JAEA-Review-2020-027.pdf:2.98MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2019. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). 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 FY2019, this report summarizes the research results of the "Development of radiation hard diamond image sensing devices". The research objective of this project is to develop image sensing devices which work under the high radiation condition. The devices will be realized using radiation hard diamond semiconductor devices as charge transfer devices and photodetectors. The research project has mainly two targets such as to confirm charge coupled devices operation on diamond unipolar devices and to characterize photo conductivity of diamond detectors.

JAEA Reports

Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; High Energy Accelerator Research Organization*

JAEA-Review 2019-040, 77 Pages, 2020/03

JAEA-Review-2019-040.pdf:4.61MB

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 "Research and Development of Radiation-resistant Sensor for Fuel Debris by Integrating Advanced Measurement Technologies". The present study aims to in-situ measure and analyze the distribution status and criticality of flooded fuel debris. For this purpose, we construct a neutron measurement system by developing compact diamond neutron sensor (200 $$mu$$m $$times$$ 510 $$mu$$m thickness) and integrated circuit whose radiation resistance was improved by circuit design. Along with the multi-phased array sonar and the acoustic sub-bottom profiling (SBP) system, the neutron measurement system will be installed in the ROV (developed by Japan-UK collaboration) and its demonstration tests will be conducted in a PCV mock-up water tank.

Journal Articles

Measurement of neutron scattering cross section of nano-diamond with particle diameter of approximately 5 nm in energy range of 0.2 meV to 100 meV

Teshigawara, Makoto; Tsuchikawa, Yusuke*; Ichikawa, Go*; Takata, Shinichi; Mishima, Kenji*; Harada, Masahide; Oi, Motoki; Kawamura, Yukihiko*; Kai, Tetsuya; Kawamura, Seiko; et al.

Nuclear Instruments and Methods in Physics Research A, 929, p.113 - 120, 2019/06

 Times Cited Count:7 Percentile:75.46(Instruments & Instrumentation)

A nano-diamond is an attractive neutron reflection material below cold neutron energy. The total neutron cross section of a nano-diamond was derived from a neutron transmission measurement over the neutron energy range of 0.2 meV to 100 meV because total neutron cross section data were not available. The total cross section of a nano-diamond with particle size of approximately 5 nm increased with a decrease in neutron energy to 0.2 meV. It was approximately two orders of magnitude larger than that of graphite at 0.2 meV. The contribution of inelastic scattering to the total cross section was to be shown negligible small at neutron energies of 1.2, 1.5, 1.9, 2.6, and 5.9 meV in the inelastic neutron scattering measurement. Moreover, small-angle neutron scattering measurements of the nano-diamond showed a large scattering cross section in the forward direction for low neutron energies.

Journal Articles

Atom-photon coupling from nitrogen-vacancy centres embedded in tellurite microspheres

Ruan, Y.*; Gibson, B. C.*; Lau, D. W. M.*; Greentree, A. D.*; Ji, H.*; Ebendorff-Heidepriem, H.*; Johnson, B. C.*; Oshima, Takeshi; Monro, T. M.*

Scientific Reports (Internet), 5, p.11486_1 - 11486_7, 2015/06

 Times Cited Count:4 Percentile:29.28(Multidisciplinary Sciences)

Journal Articles

Nanodiamond in tellurite glass, 2; Practical nanodiamond-doped fibers

Ruan, Y.*; Ji, H.*; Johnson, B. C.*; Oshima, Takeshi; Greentree, A. D.*; Gibson, B. C.*; Monro, T. M.*; Ebendorff-Heidepriem, H.*

Optical Materials Express (Internet), 5(1), p.73 - 87, 2015/01

 Times Cited Count:16 Percentile:72.75(Materials Science, Multidisciplinary)

Journal Articles

Disassembly of JT-60 tokamak device for JT-60SA Project; Disassembly of radioactivated large structures

Okano, Fuminori; Ikeda, Yoshitaka; Sakasai, Akira; Hanada, Masaya; JT-60 Team

Purazuma, Kaku Yugo Gakkai-Shi, 90(10), p.630 - 639, 2014/10

JT-60 tokamak device, as a largest nuclear fusion device in the world, started the experiments since 1985 and had accomplished the research and development of plasma performance toward the DEMO. The project has successfully completed it operation in August 2008 with many results such as accomplishment of break-even plasma condition in 1996. This disassembly was required for JT-60SA project, which is the Satellite Tokamak project under Japan-EU international corroboration to modify the JT-60 to the superconducting tokamak. This work was the first experience of disassembling a large radioactive fusion device based on Radiation Hazard Prevention Act in Japan. This report presents the outline of disassembly of JT-60 tokamak device.

Journal Articles

Development of reliable diamond window for EC launcher on fusion reactors

Takahashi, Koji; Illy, S.*; Heidinger, R.*; Kasugai, Atsushi; Minami, Ryutaro; Sakamoto, Keishi; Thumm, M.*; Imai, Tsuyoshi

Fusion Engineering and Design, 74(1-4), p.305 - 310, 2005/11

 Times Cited Count:13 Percentile:68.06(Nuclear Science & Technology)

A new diamond window with the copper-coated edge for an EC launcher is developed. The diamond window is designed to cool its disk edge. Since Cu is coated at the entire edge, ingress of cooling water into a transmission line in case of failure on the edge is negligible. In addition, corrosion of Al blaze between the edge and the Inconel cuffs can be avoided. A 170GHz, RF transmission experiment equivalent to a MW-level transmission was carried out to investigate the capability of the edge cooling. The transmission power and pulse are 55kW and 3sec, respectively. Temperature increase was 45$$^{circ}$$C and alomost became constant. Thermal calculation with tan$$delta$$ of 4.4$$times$$10$$^{-4}$$ and thermal conductivity of 1.9kW/m/K agrees with the experiment. Since tan$$delta$$ of the diamond is much higher than the actual one (tan$$delta$$=2$$times$$10$$^{-5}$$), the temperature increase corresponds to that of 1MW transmission. It concludes that the Cu coating dose not degrade the edge cooling capability and improves the reliability of the diamond window.

Journal Articles

Preliminary measurements on single and multi-crystal diamond electron cathodes

Minehara, Eisuke

Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.55 - 56, 2005/07

The next generation high brightness and high current electron source like a photo cathode, a thermionic cathode, a crystal Diamond electron cathode and others would be expected to realize the next generation ERL (energy recovery linac) based light source and SASE X-ray free-electron laser. The JAERI FEL group has recently started to develop a new crystal Diamond electron cathode technology for high current, high brightness, and long life electron source. In the presentation, we plan to explain and to discuss our strategy and a preliminary experimental measurements of the crystal Diamond cathode, and related Diamond cathode evaluation system.

Journal Articles

Thermal desorption behavior of deuterium implanted into polycrystalline diamond

Kimura, Hiromi*; Sasaki, Masayoshi*; Morimoto, Yasutomi*; Takeda, Tsuyoshi*; Kodama, Hiroshi*; Yoshikawa, Akira*; Oyaizu, Makoto*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi; et al.

Journal of Nuclear Materials, 337-339, p.614 - 618, 2005/03

 Times Cited Count:6 Percentile:42.45(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Tensile and fatigue strength of free-standing CVD diamond

Davies, A. R.*; Field, J. E.*; Takahashi, Koji; Hada, Kazuhiko

Diamond and Related Materials, 14(1), p.6 - 10, 2005/01

 Times Cited Count:19 Percentile:62.24(Materials Science, Multidisciplinary)

A CVD diamond is finding increased application and it is important to study its fatigue properties. The present paper describes research on a batch of di-electric grade CVD material. It was obtained that tensile strength at the nucleation side and the growth were side 690$$pm$$90MPa and 280$$pm$$30MPa, respectively. Some samples survived at least 95% of their critical fracture stress for 10$$^{7}$$ cycles without fatiguing.

Journal Articles

Development of EC launcher components for ITER

Takahashi, Koji; Kobayashi, Noriyuki*; Kasugai, Atsushi; Sakamoto, Keishi

Journal of Physics; Conference Series, 25, p.75 - 83, 2005/00

Recent progress of the development on the ITER equatorial EC launcher components, such as the steering mirrors, its drive system, the waveguide components and the diamond vacuum windows, is reported. Thermmo-mechanical analysis of the recent mirror design shows that maximum temperature increase of 187$$^{circ}$$C at the reflecting surface and maximum stress of 242MPa at the inner surface of the cooling tube are obtained. In the cyclic test of the spiral tube mock-up, the cyclic number of 1.3$$times$$10$$^{6}$$ is succeeded without failure. In the window development, the fabrication of the Cu-coated edge diamond window and the high power transmission test were done. The Cu-coating on the disk edge can avoid water ingress in the launcher (vessel) under the assumption of the crack formation toward edge. Transmission experiment indicative to 1.2MW, was carried out. Temperature increase of 50$$^{circ}$$C agrees with the calculation. It concludes that the Cu-coated window is capable of MW-level transmission and improves its reliability.

Journal Articles

Energetic deuterium and helium irradiation effects on chemical structure of CVD diamond

Sasaki, Masayoshi*; Morimoto, Yasutomi*; Kimura, Hiromi*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi; Okuno, Kenji*

Journal of Nuclear Materials, 329-333(Part1), p.899 - 903, 2004/08

A CVD diamond has been the reference material of a torus widow for a rf heating system in a fusion reactor. Since the window is in the circumstance of tritium, helium and radio activated dust, it is important to elucidate the effect of ions on chemical structure of the diamond, existing states of tritium and tritium inventory. Polycrystalline CVD diamond disks($$phi$$=10.0mm, t=0.21mm) used in this study are the same grade as rf windows. After sputtering the surface with 1.0 keV Ar$$^{+}$$ to remove oxygen impurity, the sample was irradiated with deuterium (D$$_{2}$$$$^{+}$$) or helium ions (He$$^{+}$$) at an angle of 0 degrees to the surface normal. The irradiation energies of deuterium and helium are 0.25 keV D$$^{+}$$ and 0.45 keV He$$^{+}$$, respectively. The structural change of the irradiated sample was measured by X-ray Photoelectron Spectroscopy (XPS) technique. The C1s peak shift toward lower binding energy side was observed when deuterium ions irradiated. This result indicates that the diamond changes to amorphous carbon due to formation of C-D bond.

Journal Articles

Energetic deuterium and helium irradiation effects on chemical structure of CVD diamond

Sasaki, Masayoshi*; Morimoto, Yasutomi*; Kimura, Hiromi*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi; Okuno, Kenji*

Journal of Nuclear Materials, 329-333(1), p.899 - 903, 2004/08

 Times Cited Count:4 Percentile:30.82(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

The Toughness of free-standing CVD diamond

Davies, A. R.*; Field, J. E.*; Takahashi, Koji; Hada, Kazuhiko

Journal of Materials Science, 39(5), p.1571 - 1574, 2004/03

 Times Cited Count:6 Percentile:29.02(Materials Science, Multidisciplinary)

A four-point bend test was used to determine the fracture toughness of mechanical grade and di-electric (optical) grade chemical vapour deposited (CVD) diamond. The validity of the test was first confirmed by measuring the toughness of alumina and confirming the results with literature values. The toughnesses of both types of CVD were similar; 8.5$$pm$$1.0 and 8.3$$pm$$0.4 MPa ($$sqrt{m}$$) respectively. This is higher than the value of 3.4$$pm$$0.5 MPa ($$sqrt{m}$$) measured for diamond by Field and Freeman, 1981 using an indentation technique. It is suggested that this is primarily due to differences in surface roughness. There were enough samples to make a preliminary study of the effect of temperature and these data are reported.

Journal Articles

Application of diamond window for infrared laser diagnostics in a tokamak device

Kawano, Yasunori; Chiba, Shinichi; Inoue, Akira*

Review of Scientific Instruments, 75(1), p.279 - 280, 2004/01

 Times Cited Count:11 Percentile:53.04(Instruments & Instrumentation)

It has been successful to apply CVD diamond plate as the vacuum window for infrared CO$$_{2}$$ laser interferometry and polarimetry for electron density measurement in the JT-60U tokamak. In comparison with to use the conventional zinc-selenide windows, the Faraday rotation component at diamond windows was small as negligible. This resulted in the improvement of the Faraday rotation measurement for a tokamak plasma by polarimetry.

Journal Articles

Strong anti-stokes luminescence from H$$^{+}$$-irradiated diamond

Xu, Y.; Naramoto, Hiroshi; Narumi, Kazumasa; Miyashita, Kiyoshi*; Kamiya, Tomihiro; Sakai, Takuro

Applied Physics Letters, 83(10), p.1968 - 1970, 2003/09

 Times Cited Count:4 Percentile:20.93(Physics, Applied)

no abstracts in English

39 (Records 1-20 displayed on this page)