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JAEA Reports

Research and development of the sample-return technique for fuel debris using the unmanned underwater vehicle (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Maritime, Port and Aviation Technology*

JAEA-Review 2021-049, 67 Pages, 2022/01

JAEA-Review-2021-049.pdf:7.54MB

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 "Research and development of the sample-return technique for fuel debris using the unmanned underwater vehicle" conducted in FY2020. The present study aims to develop a fuel debris sampling device that comprises a neutron detector with radiation resistance and enhanced neutron detection efficiency, an end-effector with powerful cutting and collection capabilities, and a manipulator under the Japan-UK joint research team. We will also develop a fuel debris sampling system that can be mounted on an unmanned vehicle. In addition, we will develop a positioning system to identify the system position, and a technique to project the counting information of optical cameras, sonar, and neutron detectors to be developed in this

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

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.

Journal Articles

Dynamic nuclear self-polarization of III-V semiconductors

Koizumi, Mitsuo; Goto, Jun*; Matsuki, Seishi*

Journal of Semiconductors, 39(8), p.082001_1 - 082001_5, 2018/08

Dynamic nuclear self-polarization (DYNASP) is a phenomenon observed in III-V semiconductors. When electrons of the valence band of a semiconductor are optically excited to the conduction band, a relaxation process of the conduction electrons induces a large nuclear polarization to suddenly occur below a critical temperature. Extending the original theoretical work of Dyakonov et al., we examined the effect of spin distribution of valence electrons excited by the circularly polarized light and the effect of external magnetic field on the phenomenon of the nuclear self-polarization. We found that the nuclear polarization is achieved even above the critical temperatures by the effect of electron polarization and of the external magnetic field. To investigate the phenomenon experimentally, we constructed an apparatus for low-temperature experiments.

Journal Articles

Diluted magnetic semiconductors with narrow band gaps

Gu, B.; Maekawa, Sadamichi

Physical Review B, 94(15), p.155202_1 - 155202_8, 2016/10

AA2016-0395.pdf:0.38MB

 Times Cited Count:16 Percentile:68.78(Materials Science, Multidisciplinary)

Journal Articles

Design study of a neutral beam injector for fusion DEMO plant at JAERI

Inoue, Takashi; Hanada, Masaya; Kashiwagi, Mieko; Nishio, Satoshi; Sakamoto, Keishi; Sato, Masayasu; Taniguchi, Masaki; Tobita, Kenji; Watanabe, Kazuhiro; DEMO Plant Design Team

Fusion Engineering and Design, 81(8-14), p.1291 - 1297, 2006/02

 Times Cited Count:10 Percentile:59.81(Nuclear Science & Technology)

Requirement and technical issues of the neutral beam inejctor (NBI) is discussed for fusion DEMO plant. The NBI for the fusion DEMO plant should be high efficiency, high energy and high reliability with long life. From the view point of high efficiency, use of conventional electrostatic accelerator is realistic. Due to operation under radiation environment, vacuum insulation is essential in the accelerator. According to the insulation design guideline, it was clarified that the beam energy of 1.5$$sim$$2 MeV is possible in the accelerator. Development of filamentless, and cesium free ion source is required, based on the existing high current/high current density negative ion production technology. The gas neutralization is not applicable due to its low efficiency (60%). R&D on an advanced neutralization scheme such as plasma neutralization (efficiency: $$>$$80%) is required. Recently, development of cw high power semiconductor laser is in progress. The paper shows a conceptual design of a high efficiency laser neutralizer utilizing the new semiconductor laser array.

Journal Articles

Centralized radioactivity measurement system for radiation control in Tokai research establishment of JAERI

Kawasaki, Katsuya

Hoken Butsuri, 40(1), p.56 - 60, 2005/03

The centralized radioactivity measurement system has been used to carry out intensively measurements of a large number and variety of samples that are necessary for the control of radioactivity in the facilities of the JAERI Tokai Establishment and its environment. The operation of the system started in 1981, and presently the system processes more than 20,000 samples a year. However, the computers of the system have aged so much that the manufacturer's support and stable operation are no longer sure. Therefore, we renewed and restructured the computer system in 2003. A client-server system was adopted in the new system. The information of samples can be registered through the intranet. The clients can also confirm the progress of processing of their samples and browse the analytical results from their own computers. The renewed system can provide some convenience functions to the clients. This report is introduced about the centralized radioactivity measurement system.

JAEA Reports

Renewal of centralized radioactivity measurement system for radiation control

Kawasaki, Katsuya; Mochizuki, Kaoru*; Suzuki, Takehiko; Kinouchi, Nobuyuki

JAERI-Tech 2004-070, 50 Pages, 2004/12

JAERI-Tech-2004-070.pdf:18.19MB

The centralized radioactivity measurement system has been used to carry out intensively measurements of a large number and variety of samples that are necessary for the control of radioactivity in the facilities of the JAERI Tokai Establishment and its environment. The operation of the system started in 1981, and presently the system processes more than 20,000 samples a year. However, the computers of the system have aged so much that the manufacturer's support and stable operation are no longer sure. Therefore, we renewed and restructured the computer system in 2003. A client-server system was adopted in the new system. The information of samples can be registered through the intranet. The clients can also confirm the progress of processing of their samples and browse the analytical results from their own computers. The renewed system can provide some convenience functions to the clients.

JAEA Reports

TIARA annual report 2003

Advanced Radiation Technology Center

JAERI-Review 2004-025, 374 Pages, 2004/11

JAERI-Review-2004-025-p0001-p0116.pdf:20.67MB
JAERI-Review-2004-025-p0117-p0247.pdf:21.34MB
JAERI-Review-2004-025-p0248-p0374.pdf:23.39MB

This annual report describes research and development activities which have been performed with the JAERI TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities from April 1, 2003 to March 31, 2004. Summary reports of 115 papers and brief descriptions on the status of TIARA in the period are contained. A list of publications, the type of research collaborations and organization of TIARA are also given as appendices.

Journal Articles

Use of liquid helium-3 as a neutron converter for a semiconductor-based neutron detector

Nakamura, Tatsuya; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*

Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.399 - 401, 2004/08

 Times Cited Count:1 Percentile:10.64(Instruments & Instrumentation)

We evaluated the neutron-detection characteristics of a cryogenic neutron detector operating at 1.6 K, which comprises a liquid helium-3 as a neutron converter and an InSb semiconductor detector. The InSb semiconductor detector detected the protons created in the nuclear reaction $$^{3}He + n rightarrow p + T$$ in the liquid helium-3, where the density of that is ~600 times larger than that of the gaseous helium-3 at room temperature.

Journal Articles

Cryogenic neutron detector by InSb semiconductor detector with high-density helium-3 gas converter

Nakamura, Tatsuya; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*

Nuclear Instruments and Methods in Physics Research A, 520(1-3), p.76 - 79, 2004/03

 Times Cited Count:8 Percentile:50.96(Instruments & Instrumentation)

The neutron-detection characteristics of a cryogenic neutron detector comprising an InSb semiconductor detector and a helium-3 gas converter were evaluated at a gas pressure of up to 12.5atm at 4.2K. The detector successfully detected stable neutrons under these conditions, where the density of the helium-3 gas is a few-hundred times higher than that at room temperature. It was found that the neutron detection efficiency was correlated with the gas pressure - even in a backward-detection configuration - in low-temperature, high-pressure helium-3.

JAEA Reports

TIARA annual report 2002

Advanced Radiation Technology Center

JAERI-Review 2003-033, 390 Pages, 2003/11

JAERI-Review-2003-033-p0001-p0187.pdf:18.1MB
JAERI-Review-2003-033-p0188-p0390.pdf:15.87MB

This annual report describes research and development activities which have been performed with the JAERI TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities from April 1, 2002 to March 31, 2003. Summary reports of 113 papers and brief descriptions on the status of TIARA in the period are contained. A list of publications, the type of research collaborations and organization of TIARA are also given as appendices.

Journal Articles

X-ray structural studies on elemental liquids under high pressures

Katayama, Yoshinori; Tsuji, Kazuhiko*

Journal of Physics; Condensed Matter, 15(36), p.6085 - 6103, 2003/09

 Times Cited Count:79 Percentile:92.88(Physics, Condensed Matter)

X-ray structural studies on several elemental liquids under high pressure are reviewed. Combination of synchrotron radiation sources and large volume presses enables us to carry out in-situ structural measurements on liquids at high pressures up to several GPa. The measurements have revealed that compressions of liquid alkali metals are almost uniform, whereas those of liquids that have covalent components in bonding are mostly anisotropic. In some elements, different types of volume dependence of the nearest neighbour distances are observed in different pressure ranges. This behaviour suggests that the liquid phase can be divided in regions. Although most of the observed structural changes are continuous, a discovery of an abrupt structural change in liquid phosphorus, which is completed over a pressure range of less than 0.05 GPa around 1GPa and 1050 $$^{circ}$$C, supports existence of a first-order liquid-liquid phase transition.

Journal Articles

Undoped-type InSb radiation detector with rapid rise time

Hishiki, Shigeomi*; Kanno, Ikuo*; Sugiura, Osamu*; Murase, Yasuhiro*; Nakamura, Tatsuya; Katagiri, Masaki

Radiation Detectors and Their Uses, p.113 - 117, 2003/00

We fabricated the schottkey-type InSb semiconductor radiation detector using an undoped InSb substrate, and evaluated the charactersitics of the alpha particle detection. The InSb detectors detected alphar particles successfully at all the tested temperature from 4.2 to 115 K. The 10-to-90% rise times of the preamplifier outputs were about 350 nsec regardless of the operating temperature. These fast rise times were about 20 times improved comparing to those from p-type InSb semiconductor detector.

JAEA Reports

TIARA annual report 2001

Advanced Radiation Technology Center

JAERI-Review 2002-035, 361 Pages, 2002/11

JAERI-Review-2002-035-p0001-p0112.pdf:14.61MB
JAERI-Review-2002-035-p0113-p0236.pdf:19.49MB
JAERI-Review-2002-035-p0237-p0361.pdf:12.43MB

This annual report describes research and developement activities which have been performed with the JAERI TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) Facilities from April 1, 2001 to March 31, 2002. Summary reports of 109 papers and brief descriptions on the status of TIARA in the period are contained. A list of publications, the type of research collaborations and organization of TIARA are also given as appendices.

Journal Articles

X-ray diffractometer for studies on molecular-beam-epitaxy growth of III-V semiconductors

Takahashi, Masamitsu; Yoneda, Yasuhiro; Inoue, Hirotane*; Yamamoto, Naomasa*; Mizuki, Junichiro

Japanese Journal of Applied Physics, Part 1, 41(10), p.6247 - 6251, 2002/10

 Times Cited Count:54 Percentile:85.9(Physics, Applied)

An X-ray diffractometer connected with a molecular-beam epitaxy (MBE) system has been constructed for in situ studies on the growing surfaces of III-V compound semiconductors. This diffractometer is based on the (4+2) type and equipped with an axis for rotating the receiving slit about the normal of the slit plane. This additional axis is used to align the resolution of the receiving slit properly for the surface X-ray diffraction measurement. For the alignment of the sample and the whole setup with respect to the X-ray beam, an XYZ-stage and an adjustable base plate are available. X-rays enter and leave the chamber through two cylindrical Be windows welded onto the MBE chamber. A graphite sheet which can be heated up to 250$$^circ$$C is placed along the inside of the Be windows to protect the Be windows from being coated with evaporated materials. Preliminary data are presented to demonstrate the feasibility of static and dynamic measurements of growing surfaces using this instrument.

JAEA Reports

TIARA annual report 2000

Advanced Radiation Technology Center

JAERI-Review 2001-039, 328 Pages, 2001/11

JAERI-Review-2001-039.pdf:41.69MB

no abstracts in English

JAEA Reports

Results and future plans for the innovative basic research on high temperature engineering

HTTR Utilization Research Committee

JAERI-Review 2001-016, 232 Pages, 2001/05

JAERI-Review-2001-016.pdf:12.01MB

no abstracts in English

JAEA Reports

JAERI TIARA annual report 1999

Advanced Radiation Technology Center

JAERI-Review 2000-024, 326 Pages, 2000/10

JAERI-Review-2000-024.pdf:33.65MB

no abstracts in English

Journal Articles

Optical ionization of DX center in AlGaAs:Se by inner-shell excitation

Yoshino, Yoko; Takarabe, Kenichi*; Ishii, Masashi*; Katayama, Yoshinori; Shimomura, Osamu

Physica B; Condensed Matter, 273-274, p.781 - 783, 1999/12

 Times Cited Count:1 Percentile:8.99(Physics, Condensed Matter)

DX state is strongly localized. This nature could be investigated by observing relaxation process of localized electrons to emptied inner shells. We have found two different optical ionization process of the DX center in Al$$_{x}$$Ga$$_{1-x}$$As:Se (x=0.33,$$N_{rm Se}=5times10^{17}$$(cm$$^{-3}$$)) by using synchrotron radiation. They are tentatively assigned to be a direct lift of an inner-shell electron to the conduction band (CB) followed by a capture of an electron at the DX center to the emptied inner shell $$({rm DX}^{-}+hnu ({rm L,} $$K-edge$$)rightarrow {rm DX}^{0}+e_{rm CB})$$ and the Auger ionization of one electron of the DX center to the CB followed by a capture of another electron to the emptied inner shell $$({rm DX}^{-}+hnu ({rm L,} $$K-edge$$)rightarrow {rm DX}^{+}+e_{rm CB}+e_{rm vacuum})$$.

44 (Records 1-20 displayed on this page)