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Furuta, Hiroshige*; Sato, Kaoru; Nishide, Akemi*; Kudo, Shinichi*; Saigusa, Shin*
Health Physics, 121(5), p.471 - 483, 2021/11
Times Cited Count：1 Percentile：15.09(Environmental Sciences)Low dose radiation induced "health effects" containing cancer risk for a Japanese radiation worker cohort is epidemiologically evaluated using the personal dose equivalent (Hp(10)). On the other hand, Hp(10) is not recommended for epidemiological evaluation of cancer risks, since the Hp(10) is widely used for radiological protection purposes. In addition, the cancer risk depends on organ doses rather than Hp(10). Thus, we developed a new method for estimating organ doses from Hp(10) of radiation workers. The developed method enables epidemiological analysis against Japanese radiation workers by considering the response characteristics of personal dosimeters, exposure geometry and energy, and body size of radiation workers in Japan. In the future, we will reconstruct organ dose conversion factor and will evaluate the risk of cancer mortality and morbidity using the organ dose in Japan.
Furuta, Hiroshige*; Tsujimura, Norio; Nishide, Akemi*; Kudo, Shinichi*; Saigusa, Shin*
Radiation Protection Dosimetry, 189(3), p.371 - 383, 2020/05
Times Cited Count：4 Percentile：43.68(Environmental Sciences)Saigusa, Mikio*; Oyama, Gaku*; Matsubara, Fumiaki*; Takii, Keita*; Sai, Takuma*; Kobayashi, Takayuki; Moriyama, Shinichi
Fusion Engineering and Design, 96-97, p.577 - 582, 2015/10
Times Cited Count：6 Percentile：45.29(Nuclear Science & Technology)A wideband polarizer has been developed for an ECCD system in JT-60SA. The groove depth of the mirrors installed in miter bends were optimized for two frequencies (110 GHz and 138 GHz) by numerical simulations. All surfaces of Poincare spheres were covered at both of the frequencies in low power test. The thermal stress of polarizer were estimated by the numerical simulations. The twister polarizer has been tested up to 0.24 MW during 3 s at 110 GHz.
Kashiwa, Yoshinori*; Saigusa, Mikio*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Fusion Engineering and Design, 81(19), p.2249 - 2256, 2006/09
Times Cited Count：4 Percentile：30.55(Nuclear Science & Technology)High efficiency ECCD operations need an obliquely propagating electromagnetic wave with a specified elliptical polarization in magnetized plasma. The polarizer is necessary in order to excite the specified polarization. In the ITER design for ECCD system, the transmitted power per one waveguide is planned to be 1 MW as CW operation. The ohmic loss evaluation code for grooved mirror polarizers which calculates tangential magnetic field to the material at exterior to the groove and inside of that was developed. Calculation results were made sure of agreement with high power experiment qualitatively, and validity of the evaluation code has been confirmed.
Maebara, Sunao; Moriyama, Shinichi; Saigusa, Mikio*; Sugimoto, Masayoshi
Proceedings of 10th European Particle Accelerator Conference (EPAC 2006) (CD-ROM), p.1990 - 1992, 2006/06
International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based neutron irradiation facility employing the D-Li stripping reaction, to produce the neutron field similar to the D-T Fusion reactor (2 MW/m
, 20 dpa/year for Fe). The required beam current of 250 mA is realized by two beam lines of 125 mA, and the output energies at injector, RFQ and DTL were designed to be 0.1, 5 and 40 MeV, respectively. The operation frequency of 175 MHz was selected to accelerate the large current of 125 mA. After an intensive beam simulation, the RFQ with a total length of 12 m was designed to keep the minimum emittance growth with the RF injection power of 2.3 MW CW. For such a 12 m-long RFQ, two coupling plates are indispensable in order to suppress higher modes in a longitudinal direction at least. From beam dynamics point views, the transmission co-efficient has been evaluated by TOUTATIS code, and it is found that the transmission decay within 0.5% can be achieved by employing a gap width of less than 4 mm for a coupling plate design.
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：17.54(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.
Saigusa, Mikio*; Takahashi, Koji; Kashiwa, Yoshinori*; Oishi, Shimpei*; Hoshi, Yuki*; Nakahata, Hiroyuki*; Kasugai, Atsushi; Sakamoto, Keishi; Imai, Tsuyoshi*
Fusion Engineering and Design, 74(1-4), p.473 - 478, 2005/11
Times Cited Count：4 Percentile：30.41(Nuclear Science & Technology)The specification of an electron cyclotron current driving (ECCD) system in International Thermonuclear Experimental Reactor (ITER) demands severe operational conditions for transmission lines and polarizers. For evaluating Ohmic loss of a miter bend type polarizer, the six polarizers were made of chromium copper alloy, installed in miter bends and tested at a frequency of 170GHz, rf power of 441kW and pulse duration of 0.1-6 seconds. The increase in temperature on the back of the grooved mirrors has been measured with thermo couplers during high power rf pulses. The Ohmic loss of grooved mirrors strongly depends on the rotation angle of the polarization plane of the incident waves and the mirror rotation in high power experiments, for example the Ohmic loss distributed from 0.2% to1.6%. The thermal analysis of grooved mirror has been performed with the 3D FEM code: FEVA. The all strange behavior of Ohmic loss of polarizers could be explained, theoretically.
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：0.01(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; Moriyama, Shinichi; Saigusa, Mikio*; Sugimoto, Masayoshi
JAERI-Research 2005-007, 11 Pages, 2005/03
JAERI-Research-2005-007.pdf:2.59MB
no abstracts in English
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.
Murakami, Tsutomu; Hishida, Masahiko; Kisohara, Naoyuki; Hayafune, Hiroki; Hori, Toru; Fujii, Tadashi; Uchita, Masato; Chikazawa, Yoshitaka; Uno, Osamu; Saigusa, Toshiie; et al.
JNC TY9400 2004-014, 78 Pages, 2004/07
JNC-TY9400-2004-014.pdf:7.97MB
This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2003, which is the third year of Phase 2. In the JFY2003 design study, critical subjects related to safety, structural integrity and thermal hydraulics which found in the last fiscal year has been examined and the plant concept has been modified. Furthermore, fundamental specifications of main systems and components have been set and economy has been evaluated. In addition, as the interim evaluation of the candidate concept of the FBR fuel cycle is to be conducted, cost effectiveness and achievability for the development goal were evaluated and the data of the three large-scale reactor candidate concepts were prepared.
Hishida, Masahiko; Murakami, Tsutomu; Kisohara, Naoyuki; Fujii, Tadashi; Uchita, Masato; Hayafune, Hiroki; Chikazawa, Yoshitaka; Hori, Toru; Saigusa, Toshiie; Uno, Osamu; et al.
JNC TY9400 2004-012, 97 Pages, 2004/07
JNC-TY9400-2004-012.pdf:12.55MB
Based on the concept of a plant consisting of four modules with a capacity of 750 MWe each, which has been established by the end of FY2002, a concept of the entire plant was proposed, reflecting the modifications related to the high internal conversion type core, the double-wall straight tube steam generator (SG), and the fuel storage system. Concept studies were also performed to overcome the drawbacks of the sodium and to achieve in-service inspection and repair as easily as in light water reactor. Furthermore, feasibility studies were carried out to confirm the design, which included safety, thermal-hydraulics and the structures of the primary reactor auxiliary cooling system and the double-wall straight tube SG. A prospect for realization of this plant concept has been obtained through the evaluation results. In addition, as the interim evaluation of the candidate concepts of the FBR fuel cycle is to be conducted, cost effectiveness and achievability for the development goal were evaluated and the data of the three medium-scale reactor candidate concepts were prepared.
Kashiwa, Yoshinori*; Saigusa, Mikio*; Takahashi, Koji; Oishi, Shimpei*; Hoshi, Yuki*; Kasugai, Atsushi; Sakamoto, Keishi; Imai, Tsuyoshi
Proceedings of 2004 International Symposium on Microwave Science and Its Application to Related Fields (Microwave 2004), p.527 - 530, 2004/07
An electron cyclotron current drive (ECCD) system is, especially, necessary to suppress the neoclassical tearing mode instability in ITER. The polarizers are one of the important components in the ECCD system, to generate optimum polarization for an efficient ECCD. An ohmic loss of the polarizers is evaluated, when 170GHz, high power RF wave taransmits, in oreder to investigate its performance. The maximum temperature increase on the back plate of the deep grooved and the conventinal type were 65C and 30C, respectively. RF power and pulse were 441kW and 6sec, respectively. The dependence of temperature increase on the plolarizer angle obtained in the experiment agrees with the calculation, qualitatively. It was also found that the significant reduction of ohmic loss on the polarizers was achievable with the optimized rotation angle of the linearly polarized incident wave.
Konomura, Mamoru; Ogawa, Takashi; Okano, Yasushi; Yamaguchi, Hiroyuki; Murakami, Tsutomu; Takaki, Naoyuki; Nishiguchi, Youhei; Sugino, Kazuteru; Naganuma, Masayuki; Hishida, Masahiko; et al.
JNC TN9400 2004-035, 2071 Pages, 2004/06
JNC-TN9400-2004-035.pdf:76.42MB
The attractive concepts for Sodium-, lead-bismuth-, helium- and water-cooled FBRs have been created through using typical plant features and employing advanced technologies. Efforts on evaluating technological prospects of feasibility have been paid for these concepts. Also, it was comfirmed if these concepts satisfy design requierments of capability and performance presumed in the feasibilty study on commertialization of Fast Breeder Reactor Systems. As results, it was concluded that the selection of sodium-cooled reactor was most rational for practical use of FBR technologies in 2015.
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count：2 Percentile：6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-
. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Kisohara, Naoyuki; Hishida, Masahiko; Nibe, Nobuaki; Hori, Toru; Fujii, Tadashi; Uchita, Masato; Chikazawa, Yoshitaka; Saigusa, Toshiie; Uno, Osamu; Soman, Yoshindo; et al.
JNC TY9400 2003-015, 103 Pages, 2003/09
JNC-TY9400-2003-015.pdf:6.39MB
In Phase I of the "Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)", an advanced loop type reactor has been selected as a promising concept of sodium-cooled middle-scale modular reactor, which has a possibility to fulfill the design requirements of the F/S. This report summarizes the results of the design study on the sodium-cooled middle-scale modular reactor performed in JFY2002, which is the second year of Phase 2. The construction cost of the sodium-cooled middle-scale modular reactor, which has been constructed in JFY2002, was almost achieved the economical goal. But its achievability was not sufficient to accept the concept. In order to reduce the construction cost, the plant concept has been re-constructed based on the 50 MWe plant studied in JFY2002. After that, fundamental specifications of main systems and components for the new concept have been set, and critical subjects have been examined and evaluated. In addition, in order to achieve the further cost reduction, the plant with simplified secondary system, the plant with electric magnetic pump in secondary system, and the fuel handling system are examined and evaluated. As a result of this study, the plant concept of the sodium-cooled middle-scale modular reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000 yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowingdown candidate concepts at the end of Phase 2.
Kisohara, Naoyuki; Hishida, Masahiko; Nibe, Nobuaki; Hori, Toru; Fujii, Tadashi; Uchita, Masato; Chikazawa, Yoshitaka; Saigusa, Toshiie; Uno, Osamu; Soman, Yoshindo; et al.
JNC TY9400 2003-014, 52 Pages, 2003/09
JNC-TY9400-2003-014.pdf:3.12MB
In Phase 2 of the F/S, it is planed to precede a preliminary conceptual design of a sodium-cooled large-scale reactor based on the design of the advanced loop type reactor. Through the design study, it is intended to construct such a plant concept that can show its attraction and competitiveness as a commercialized reactor. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2002, which is the second year of Phase 2. In the JFY2002 design study, critical subjects related to safety, structural integrity and thermal hydraulics which found in the last fiscal year has been examined and the plant concept has been modified. Furthermore, fundamental specifications of main systems and components have been set and economy has been evaluated.As a result of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000yens/kWe, etc.) and has a prospect to solve the critical subjects.
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Chujo, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
no abstracts in English
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Cho, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
Times Cited Count：33 Percentile：68.89(Physics, Fluids & Plasmas)no abstracts in English
Maebara, Sunao; Morishita, Takatoshi; Sugimoto, Masayoshi; Imai, Tsuyoshi; Takeuchi, Hiroshi; Sazawa, Shingo*; Saigusa, Mikio*
Proceedings of 2003 Particle Accelerator Conference (PAC 2003) (CD-ROM), p.2829 - 2831, 2003/00
It is indispensable to obtain the technical know-how of the IFMIF RFQ design in the development of RFQ system. It is very important to determine the mesh size in analysis code of the RFQ design. The design of 175MHz RFQ mock-up modules has been done by MAFIA code. Based on this design, the 175MHz RFQ mock-up which consists of two end-plate modules and RFQ modules are fabricated for low power tests. The resonant frequencies have been measured in RFQ length of 1.1m and 2.1m.The measured frequencies are in a good agreement with the calculated values within 1MHz when the mesh size is 1/350 of the longitudinal length.
