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Collaborative Laboratories for Advanced Decommissioning Science; Yokohama National University*
JAEA-Review 2024-024, 88 Pages, 2024/11
JAEA-Review-2024-024.pdf:4.5MB
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 FY2022. 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 FY2022, this report summarizes the research results of the "Development of passive wireless communication systems operatable under inferior-wireless environment with obstacles" conducted in FY2022. The present study aims to develop a wireless system, sensor positioning algorithms, and wireless area formation technology for electromagnetically shielded areas. We developed a base station antenna and a sensor node that use 2.45 GHz for downlink and 4.9 GHz, which is the second harmonic, for uplink. We also confirmed that the developed circuit and antenna operate in a strong radioactive environment.
Collaborative Laboratories for Advanced Decommissioning Science; i-Lab*
JAEA-Review 2023-029, 77 Pages, 2024/05
JAEA-Review-2023-029.pdf:3.98MB
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 FY2022. 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 "Challenge to advancement of debris composition and direct isotope measurement by microwave-enhanced LIBS" conducted from FY2020 to FY2022. The present study aims to increase the emission intensity of LIBS (laser-induced breakdown spectroscopy) by superimposing MW (microwave) and apply it to uranium isotope measurement. In FY2022, we improved the cooling method and reduce unnecessary functions in of the semiconductor microwave oscillator, and apply the optimized conditions obtained from simulations to the LIBS experiment for the microwave antenna gave better results.
Collaborative Laboratories for Advanced Decommissioning Science; i-Lab*
JAEA-Review 2022-042, 67 Pages, 2023/01
JAEA-Review-2022-042.pdf:7.42MB
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 FY2021. 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 "Challenge to advancement of debris composition and direct isotope measurement by microwave-enhanced LIBS" conducted in FY2021. The present study aims to increase the emission intensity of LIBS (laser-induced breakdown spectroscopy) by superimposing MW (microwave) and apply it to uranium isotope measurement. In FY2021, after confirming that there was no problem in terms of specifications including noise leakage by downsizing the semiconductor MW oscillator and evaluating it as a single unit, the possibility of uranium isotope measurement was examined by applying it to the LIBS experiment. In addition, the optimized design of the MW antenna was carried out. By applying them, we confirmed the actual performance, …
Takahashi, Koji; Kobayashi, Noriyuki*; Kasugai, Atsushi; Sakamoto, Keishi
Fusion Engineering and Design, 81(1-7), p.281 - 287, 2006/02
Times Cited Count：5 Percentile：35.61(Nuclear Science & Technology)In the ITER, an EC H&CD steering antenna mirror was designed to reflect eight or nine 1MW-wave beams. The cross-section and thickness of the mirror are 250
360 mm
and 50mm, respectively. The thermal and stress analysis under the ITER condition show that the copper alloy(DSCu) mirror with stainless steel cooling tubes inside is considered acceptable. The EC H&CD antenna system for the ITER must have a dog-legged transmission lines so as to protect the diamond windows or superconducting magnets of a tokamak. A 90
miter bend, which consists of waveguides and a reflection mirror, is required to make the structure. The mock-up of the mirror based on the ITER design was fabricated and the high power transmission experiment was carried out. The mm-wave transmission with power/pulse length 450kW/5.0sec, was demonstrated. The ohmic loss is estimated to be 
0.2%, which agrees with the calculation based on electrical resistivity of DSCu 2.010
m.
Seki, Masami; Moriyama, Shinichi; Shinozaki, Shinichi; Hasegawa, Koichi; Hiranai, Shinichi; Yokokura, Kenji; Shimono, Mitsugu; Terakado, Masayuki; Fujii, Tsuneyuki
Fusion Engineering and Design, 74(1-4), p.273 - 277, 2005/11
Times Cited Count：3 Percentile：23.90(Nuclear Science & Technology)no abstracts in English
Moriyama, Shinichi; Seki, Masami; Terakado, Masayuki; Shimono, Mitsugu; Ide, Shunsuke; Isayama, Akihiko; Suzuki, Takahiro; Fujii, Tsuneyuki; JT-60 Team
Fusion Engineering and Design, 74(1-4), p.343 - 349, 2005/11
Times Cited Count：7 Percentile：44.26(Nuclear Science & Technology)no abstracts in English
Maebara, Sunao; Moriyama, Shinichi; Saigusa, Mikio*; Sugimoto, Masayoshi; Imai, Tsuyoshi; Takeuchi, Hiroshi
Fusion Engineering and Design, 75-79, p.823 - 827, 2005/11
Times Cited Count：2 Percentile：17.30(Nuclear Science & Technology)An RF-Input coupler with a multi-loop antenna using co-axial waveguides has been developed for the RFQ linac on IFMIF. In case of using a loop antenna, the loop antenna structure will affected phase difference and power balance in each cavity. A mock-up loop antenna using the pipe diameter of 10mm was fabricated, phase differences and power balances were measured by a low power test. It is found that it is necessary to shorten the installed depth up to 3 cm to make the phase differences and power balance small. But, from a withstanding voltage, it is difficult to couple multi-MW with the single coupler. The coupling with multi-loop antennas using two or four loops is better than one loop antenna from the point views of both withstanding voltage and power balance. The phase difference and power balance were also measured in both cases. A good average phase-difference of 179. and a good RF power balance within 8% error for each cavity were obtained. These results showed one of feasibility for an RF-Input coupler with a multi-loop antenna in the IFMIF 175 MHz RFQ.
Moriyama, Shinichi; Kajiwara, Ken*; Takahashi, Koji; Kasugai, Atsushi; Seki, Masami; Ikeda, Yoshitaka; Fujii, Tsuneyuki; JT-60 Team
Review of Scientific Instruments, 76(11), p.113504_1 - 113504_6, 2005/11
Times Cited Count：6 Percentile：33.05(Instruments & Instrumentation)A compact antenna has been designed and fabricated to enable millimeter wave beam scan in the toroidal and the poloidal directions of the JT-60U Tokamak, for electron cyclotron heating (ECH) and current drive (ECCD) experiments. It consists of fast movable flat mirror mounted on the Tokamak vacuum vessel, and rotary focusing mirror attached at the end of the waveguide supported from outside of the vacuum vessel. This separate support concept enables compact structure in the shallow port (0.68 m 0.54 m 0.2m) sharing with a sub-port for an independent diagnostic system. The flat mirror is driven during a shot by a servo-motor with a 3 m long drive shaft to refuse influence of the high magnetic field to the motor. The focusing mirror is rotated by a simple mechanism with a push rod and an air cylinder. The antenna has been operated reliably for 3 years after small improvement in the rotary mechanism. It has been contributing ECH and ECCD experiments especially current profile control, in JT-60U.
Moriyama, Shinichi; Shinozaki, Shinichi
Japanese Journal of Applied Physics, Part 1, 44(8), p.6224 - 6229, 2005/08
Times Cited Count：1 Percentile：4.63(Physics, Applied)The control system of RF heating system in JT-60U has been improved with a concept of dispersion processing and featuring a real time waveform shaping method. It is proper that the brand-new, dispersion processing system has higher performance and reliability than old single processor system before modification, however it is worthy of mention that improvement on operation roll sharing, using the real time waveform shaping, has enabled more efficient and smooth operation. The typical roll sharing is that a simple rectangular waveform of the RF heating power is set by the experiment operator, and the waveform is re-shaped with the parameter set by the RF operator who knows deeply the condition of the RF system at that time. The simple and flexible composition of the new control system will also enable further improvement of hardware to enhance plasma performance that is inevitable to the devices for fusion experiment.
Maebara, Sunao; Moriyama, Shinichi; Saigusa, Mikio*; Sugimoto, Masayoshi; Imai, Tsuyoshi*; Takeuchi, Hiroshi
Fusion Science and Technology, 47(4), p.941 - 945, 2005/05
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)For tuning the 175MHz RFQ used in the baseline design of IFMIF, the RF power-balance control by slug tuner is indispensable because the RF power-balance for quadrupole operation mode (TE
) in each RFQ quadrant will be affected by the insertion of the loop antennas and pick-up coils. In this study, RF power-balance recovery by slug tuners have been measured by using a low power module of 175MHz RFQ mock-up. The optimal insertion depth of loop antenna was determined to be 3 cm for realizing the appropriate phase differences of TE mode. Under this condition, cylindrical slug tuners were inserted, and S
parameters in each cavity were measured. As a typical result, RF power-balance control less than 20% error can be achieved in case of 
3cm tuner up to 3cm insertion.
Maebara, Sunao; Goniche, M.*; Kazarian, F.*; Seki, Masami; Ikeda, Yoshitaka; Imai, Tsuyoshi*; Beaumont, B.*
Review of Scientific Instruments, 76(5), p.053501_1 - 053501_7, 2005/05
Times Cited Count：1 Percentile：9.98(Instruments & Instrumentation)Development of a plasma facing module using Cold Isostatic Pressing Graphite (CIPG) had been done for a heat-resistant LHCD antenna. A thin stainless film (10
m), molybdenum film (10m) and copper film (50m) are laid to overlap each other on the CIPG materials, the CIPG surfaces were successfully coated with copper layer by diffusion bonding method. This module has four waveguides and a water cooling channel, the length is 206 mm. High power long pulse operation was successfully achieved up to 250 kW (125 MW/m)/700s. The module has been successfully tested at a RF power density which is equivalent, in terms of RF electric field (5kV/cm), to the one proposed for the LHCD antenna of ITER-FEAT. The outgassing rate of the copper-coated CIPG is estimated to be 3.2-5.110
Pa.m
/s.m at 100C, it is assessed that a pumping system is not required to evacuate the pressure in the LHCD antenna.
Goniche, M.*; Kazarian, F.*; Bibet, P.*; Maebara, Sunao; Seki, Masami; Ikeda, Yoshitaka; Imai, Tsuyoshi*
Journal of Vacuum Science and Technology A, 23(1), p.55 - 65, 2005/01
Times Cited Count：2 Percentile：9.16(Materials Science, Coatings & Films)Outgassing rates have been measured for long duration (100-4700 seconds) of RF transmission at high power density (50-200 MW/m) for waveguides made of OFHC copper, dispersoid copper, copper-coated carbon fiber composite and copper-coated graphite. The measurements were performed on multi-waveguide(2 to 8)mockups, using a test bed facility equipped with a 3.7 GHz klystron. The effect on the outgassing rate of waveguide surface temperature and of initial wall gas loading('conditioning'), is examined. It is concluded that an outgassing rate of 110
Pams
m
and 510 Pamsm at 300C and 400C respectively, can be expected for the tested material. Based on these measurement results, it is further concluded that no additional pumping will be needed for the LHRF antenna proposed for ITER.
Maebara, Sunao; Moriyama, Shinichi; Sugimoto, Masayoshi; Saito, Yuichi*; Saigusa, Mikio*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.904 - 906, 2005/00
The IFMIF is an accelerator-based neutron irradiation facility employing the D-Li stripping reaction. The required beam current of 250 mA is realized by two beam lines of 125mA, and the output energies at injector, RFQ and DTL were designed to be 0.1, 5 and 40 MeV, respectively. The operation frequency of 175MHz was selected to accelerate the large current of 125mA. After an intensive beam simulation, the RFQ with a total length of 12m was designed to keep the minimum emittance growth with the RF injection power of 2.3MW CW. For such a 175MHz RFQ, a design for RF input coupler with loop antenna and co-axial window, supplying RF power shared by 3 4 ports, was conducted by using MW-Studio code. In order to withstand the voltage exceeding 200kW CW per one loop antenna, the co-axial line of 4 1/16" diameter is necessary, and it is found that the electric field distortion factor less than 1% can be achieved in beam bore only by employing the 4-loop antenna configuration providing the same power for each quadrants.
Moriyama, Shinichi; Ikeda, Yoshitaka; Seki, Masami; Sakamoto, Keishi; Kasugai, Atsushi; Takahashi, Koji; Kajiwara, Ken*; Isayama, Akihiko; Suzuki, Takahiro; Fukuda, Takeshi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 79(9), p.935 - 944, 2003/09
An optimization of current profile is a key issue for attaining higher plasma performance in Tokamak, such as stabilization of neo-classical tearing mode (NTM) and control of internal transport barrier (ITB). In JT-60U, a high power electron cyclotron heating (ECH) system at 110 GHz has been developed for local plasma heating and current drive. We have demonstrated the technical feasibility of the antenna which can scan EC beam in both toroidal and poloidal directions. The toroidal scan enabled co- and counter- current drive and also pure plasma heating. An automatic stabilization of the NTM was demonstrated by means of current drive at the location of magnetic island using a feedback control of poloidal beam angle. The total injected power has been extended to 2.8 MW for 3.6 sec and each gyrotron delivers ~ 1 MW for 5 sec. This world record of the injection energy was attained by an upgrade of the gyrotron using RF absorber in the beam tunnel to suppress the parasitic oscillation and improvement of the transmission efficiency of the waveguide system.
Hiranai, Shinichi; Shinozaki, Shinichi; Sato, Fumiaki*; Suzuki, Yasuo*; Yokokura, Kenji; Moriyama, Shinichi; Ikeda, Yoshitaka
JAERI-Tech 2003-038, 39 Pages, 2003/03
JAERI-Tech-2003-038.pdf:9.06MB
The JT-60U electron cyclotron heating (ECH) System injects a millimeteric wave at 110 GHz (EC beam) into the JT-60 Plasma, and heats the plasma or drives a current locally to enhance the confinement performance of the JT-60 plasma. The system consists of four sets of high power gyrotrons, high voltage power supplies and transmission lines, and two antennas that launch electron cyclotron (EC) beams toward the plasma. The key features of the injection control system are steering of the direction of the EC beam by driving the movable mirror in the antenna, and capability to set any combination of polarization angle and ellipticity by rotating the two grooved mirrors in the polarizers. This report represents the design, fabrication and improvements of the injection control system.
Moriyama, Shinichi; Fujii, Tsuneyuki; Kimura, Haruyuki; Anno, Katsuto; Yokokura, Kenji; Shinozaki, Shinichi; Terakado, Masayuki; Hiranai, Shinichi; Saigusa, Mikio*
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.467 - 481, 2002/09
Times Cited Count：7 Percentile：43.66(Nuclear Science & Technology)no abstracts in English
Moriyama, Shinichi; Kimura, Haruyuki; Fujii, Tsuneyuki; Saigusa, Mikio*; Imai, Tsuyoshi; Yamamoto, Takumi; Arai, H.*; Ota, K.*
Fusion Engineering and Design, 45(1), p.31 - 40, 1999/00
Times Cited Count：2 Percentile：21.03(Nuclear Science & Technology)no abstracts in English
Moriyama, Shinichi; Fujii, Tsuneyuki; Kimura, Haruyuki; Arai, Hiroyuki*; Ota, K.*
Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering (SOFE '99), p.399 - 402, 1999/00
no abstracts in English
Moriyama, Shinichi; Kimura, Haruyuki; Fujii, Tsuneyuki; Saigusa, Mikio*; Arai, H.*
Japanese Journal of Applied Physics, 37(6A), p.3536 - 3540, 1998/06
Times Cited Count：4 Percentile：23.82(Physics, Applied)no abstracts in English
Moriyama, Shinichi; Kimura, Haruyuki; Saigusa, Mikio; Fujii, Tsuneyuki; ; ; ;
Fusion Engineering and Design, 39-40, p.135 - 142, 1998/00
no abstracts in English
