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La reactionOkuizumi, Mao*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ino, Takashi*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; et al.
Physical Review C, 111(3), p.034611_1 - 034611_6, 2025/03
Kato, Toru*; Takahashi, Hiroki*; Yamashita, Meguru*; Doi, Akio*; Imabuchi, Takashi
Artificial Life and Robotics, 30(1), p.126 - 135, 2025/02
Nagasawa, Makoto*; Shimizu, Yusuke*; Yamaguchi, Akiko; Tokunaga, Kohei; Mukai, Hiroki*; Aoyagi, Noboru; Mei, H.; Takahashi, Yoshio*
Chemical Geology, 670, p.122431_1 - 122431_25, 2024/12
Times Cited Count：0 Percentile：0.00(Geochemistry & Geophysics)Machida, Masahiko; Yamada, Susumu; Kim, M.; Tanaka, Satoshi*; Tobita, Yasuhiro*; Iwata, Ayako*; Aoki, Yuto; Aoki, Kazuhisa; Yanagisawa, Kenichi*; Yamaguchi, Takashi; et al.
RIST News, (70), p.3 - 22, 2024/09
Inside the Fukushima Daiichi Nuclear Power Plant (1F), there are many locations with high radiation levels due to contamination by radioactive materials that leaked from the reactor. These pose a significant obstacle to the smooth progress of decommissioning work. To help solve this issue, the Japan Atomic Energy Agency (JAEA), under a subsidy from the Ministry of Economy, Trade, and Industry's decommissioning and contaminated water management project, is conducting research and development on digital technologies to improve the radiation environment inside the decommissioning site. This project, titled "Development of Technology to Improve the Environment Inside Reactor Buildings (Enhancing Digital Technology for Environment and Source Distribution to Reduce Radiation Exposure)," began in April of FY 2023. In this project, the aim is to develop three interconnected systems: FrontEnd, Pro, and BackEnd. The FrontEnd system, based on the previously developed 3D-ADRES-Indoor (prototype) from FY 2021-2022, will be upgraded to a high-speed digital twin technology usable on-site. The Pro system will carry out detailed analysis in rooms such as the new office building at 1F, while the BackEnd system will serve as a database to centrally manage the collected and analyzed data. This report focuses on the FrontEnd system, which will be used on-site. After point cloud measurement, the system will quickly create a 3D mesh model, estimate the radiation source from dose rate measurements, and refine the position and intensity of the estimated source using recalculation techniques (re-observation instructions and re-estimation). The results of verification tests conducted on Unit 5 are also presented. Furthermore, the report briefly discusses the future research and development plans for this project.
Kobayashi, Fuminori; Kamiya, Junichiro; Takahashi, Hiroki; Suzuki, Yasuo*; Tasaki, Ryuta*
JAEA-Technology 2024-007, 28 Pages, 2024/07
JAEA-Technology-2024-007.pdf:2.52MB
In J-PARC LINAC, the vacuum system is in place to maintain an ultra-high vacuum in the beam transport line (LINAC to 3GeV RCS beam transportation line: L3BT) between the LINAC to the 3GeV synchrotron. The vacuum system is installed in the LINAC and L3BT buildings and consists of vacuum pumps, vacuum gauges, beam line gate valves (BLGVs), and other vacuum. In existing vacuum systems, vacuum equipment is controlled independently for each area, and vacuum equipment can be operated regardless of the status of adjacent areas. This makes it impossible to eliminate erroneous operation due to human error. In addition, when a vacuum deterioration occurs in the beam transport line, the vacuum deterioration ILK signal is transmitted to the BLGV relay unit via the MPS transmission signal, which causes the BLGVs to be forcibly closed. Because the ILK signal transmission range extends to all BLGVs in the L3BT, however, BLGVs in areas unaffected by vacuum deterioration are also forced to close. This could cause problems such as unnecessary open/close operations leading to more frequent maintenance cycles of the BLGVs. In addition, since the BLGV is operated using the MPS signal path, maintenance of the vacuum control system requires work involving the MPS signal path, making it difficult to maintain the vacuum control system alone and making the work complicated. To solve these problems, it is necessary to improve maintainability by separating the signal paths and automatically controlling BLGV separately. Therefore, the vacuum control system was modified and constructed with the aim of realizing a control system that takes into account the safety and efficient maintenance and operation of the L3BT vacuum system. This report summarizes the development and use of the L3BT vacuum system control system.
Takahashi, Hiroki; Saha, P. K.; Yoshimoto, Masahiro; Sawabe, Yuki*
Journal of Physics; Conference Series, 2687(7), p.072019_1 - 072019_5, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)In J-PARC 3 GeV Rapid Cycling Synchrotron, the synchronized data system using reflective memory has been constructed. In order to support the requirement of using larger size data in high intensity beam operation in the future, a new synchronized data generation method has been proposed. The new method implements in the measurement system the functions performed by the high-level computer in the current system, thereby realizing synchronized data generation using data transfer via LAN. In this study, we have constructed a test bench for the new synchronized data system that implements the proposed method and verified its performance. This result leads to the development of the new synchronized data system based on data transfer via LAN. In this paper, we describe the outline of the new synchronized data generation method and the results of performance tests.
Kato, Toru*; Takahashi, Hiroki*; Yamashita, Meguru*; Doi, Akio*; Imabuchi, Takashi
Proceedings of 29th International Symposium on Artificial Life and Robotics (AROB 29th 2024) (Internet), p.1097 - 1100, 2024/01
Takahashi, Hiroki*; Kato, Toru*; Yamashita, Meguru*; Doi, Akio*; Imabuchi, Takashi
Proceedings of 29th International Symposium on Artificial Life and Robotics (AROB 29th 2024) (Internet), p.1093 - 1096, 2024/01
Watanabe, Kazuhiko*; Niki, Kazuaki*; Takahashi, Hiroki; Yamamoto, Noboru*; Yoshimoto, Masahiro; Fukuta, Shimpei*
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.844 - 847, 2023/11
J-PARC Personnel Protection System (PPS) acquires and displays data using by PPS Data System. PPS Data System has been using SCADA software, but it has become difficult to handle increased data due to the limited number of signals. Then, it became necessary to build PPS Data System using different software. Therefore, we decided to construct a new system using EPICS, which has been used in the J-PARC control system. On the other hand, PPS is a system that guarantees the safety of personnel, so it cannot be shut down for long periods of time. In addition, it is the most important safety system and must maintain high reliability and stability, so it would be dangerous to update the entire system in a short period of time. Therefore, we decided to divide the PPS Data System by function and replace it with the new system partially while operating the current system. This allows us to verify the operation of the updated parts and correct any problems without compromising the functionality of the PPS, and to construct a new system with high reliability and stability. This presentation will provide an overview of the new system, the updating process, and the progress.
Yoshimoto, Masahiro; Takahashi, Hiroki; Harada, Hiroyuki; Chimura, Motoki; Fuwa, Yasuhiro; Hayashi, Naoki; Kuriyama, Yasutoshi*; Sawabe, Yuki*; Hatakeyama, Shuichiro*
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.839 - 843, 2023/11
In the J -PARC 3GeV synchrotron accelerator (RCS), a new signal processing system for beam monitors is been developing to replace the existing system for the main beam monitors that monitor the stability of the accelerator: beam loss monitor, beam position monitor and beam current monitor. The new system will consist of a TAG server and an ADC module that can be used commonly for the three main monitors. The main design concepts of the new system are: (1) the TAG server divides various beam J-PARC tag information to each ADC module, (2) the ADC module converts acquisition data from beam monitors to digital signals by ADC and performs high-speed analysis by FPGA with switching analysis methods to suit each monitor, (3) the ADC module periodically outputs the analysis data with tag information by packing the signal processing data of all shots for about 10 seconds, and also outputs any one shot data on-demand, and (4) the raw waveform data, the latest four shots of FFT-related data in the process of analysis and bunch data for each cycle are stored in the internal memory of the ADC module, and the data can be read out as needed. In this presentation, we will report on the progress of the data acquisition test of tag information reading and beam monitor signals using the prototype under development.
-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samplesLi, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count：10 Percentile：69.36(Chemistry, Analytical)no abstracts in English
Takahashi, Hiroki; Miyao, Tomoaki*; Hatakeyama, Shuichiro; Ishiyama, Tatsuya*
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.300 - 304, 2023/01
At J-PARC Linac, some beam dumps (BDs) are used for beam conditioning and study. A beam window is installed in the beamlines of each BD. A beam window protection system has been installed in the Linac 0-deg BD after a trouble with the beam window in 2018. However, the current system has not proved to be fully functional for future beam upgrade plan and etc. Then, we started to develop a beam window protection unit with a new function to measure the beam in real time and to inhibit the beam even in the middle of a beam pulse. In this paper, the details and performance of the developed beam window protection unit will be described.
Fujiyama, Hiroki*; Takahashi, Hiroki; Okabe, Kota; Ito, Yuichi*; Hatakeyama, Shuichiro; Suzuki, Takahiro*; Otsu, Satoru*; Yamakawa, Ryuto*
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.529 - 531, 2023/01
Stepper motors are used for mechanical drive in collimators and wire scanner monitors of J-PARC accelerators. Many of these drive unit hardware have been used since the beginning of J-PARC construction, and it is necessary to take measures against aging deterioration. Therefore, we started updating the motor and control system from around 2017. However, when the stepper motor was updated to the current product in the RCS H0 collimator, a malfunction occurred. This is because the drive unit control system cannot correctly recognize the state of the LS (limit switch) due to the noise generated by the motor driver, which hinders the operation. When the noise generated from the old and new stepper motors was measured in a simple test environment for confirmation, it was found that the current product was clearly larger. As a countermeasure, when the wiring of the stepper motor, which was bundled in a single multi-core cable, was separated into separate cables for the power system and LS signal system, the noise level was reduced to about 1/10 and normal operation was restored. I was able to. In this case, we report on noise countermeasures for the RCS H0 collimator drive unit.
Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count：7 Percentile：77.01(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Cs activity concentration in the aquatic insect 
(Tricoptera: Stenopsychidae) in the Ota River, Fukushima, JapanIshii, Yumiko*; Miura, Hikaru*; Jo, J.*; Tsuji, Hideki*; Saito, Rie; Koarai, Kazuma; Hagiwara, Hiroki; Urushidate, Tadayuki*; Nishikiori, Tatsuhiro*; Wada, Toshihiro*; et al.
PLOS ONE (Internet), 17(5), p.e0268629_1 - e0268629_17, 2022/05
Times Cited Count：6 Percentile：44.24(Multidisciplinary Sciences)We investigated the variability in Cs activity concentration in individual aquatic insects in detritivorous caddisfly () and carnivorous dobsonfly (
) larvae from the Ota River, Fukushima. Caddisfly larvae showed sporadically higher radioactivity, whereas no such outliers were observed in dobsonfly larvae. Autoradiography and scanning electron microscopy analyses confirmed that these caddisfly larvae samples contained radiocesium-bearing microparticles (CsMPs), which are insoluble Cs-bearing silicate glass particles. CsMPs were also found in potential food sources of caddisfly larvae, such as periphyton and drifting particulate organic matter, indicating that larvae may ingest CsMPs along with food particles of similar size. Although CsMPs distribution and uptake by organisms in freshwater ecosystems is relatively unknown, our study demonstrates that CsMPs can be taken up by aquatic insects.
Yamane, Ikumi; Takahashi, Nobuo; Sawayama, Kengo; Nishiwaki, Hiroki; Matsumoto, Takashi; Ogawa, Jumpei; Nomura, Mitsuo; Arima, Tatsumi*
JAEA-Technology 2021-038, 18 Pages, 2022/02
JAEA-Technology-2021-038.pdf:1.61MB
We have dismantled uranium enrichment facilities in Ningyo-toge Environmental Engineering Center since their operation finished in 2001, and the total amount of metallic wastes is estimated to be about 130 thousand tons. Eighty percent of them can be disposed as nonradioactive waste (NR), but there are some steel parts possibly uranium-contaminated. We need removing painted surface of such steels and radiologically surveying to dispose them as NRs. Though painted surfaces have been conventionally removed through hand working with grinders, this manual work requires installation of green house, protective clothing, and full-face mask, in order to prevent dispersion and inhalation of airborne dusts. We desire further developments of surface cleaning techniques to reduce time, cost, workload, and secondary waste generation caused by excessive grinding. Therefore, in this study, we focused on the laser cleaning technology used for the separation and removal of paint films at construction sites. In order to improve the coating separation and removal technology for NR objects, we evaluated the coating separation and removal performance of NR steel surface by laser cleaning system, observed the coating scattering behavior by high-speed camera and investigated the coating recovery method, evaluated the laser separation and removal performance of steel surface powder, and thermodynamically evaluated the uranium compounds on steel surface. We additionally evaluated the feasibility of laser cleaning techniques in our works basing on these results, and discussed future work plans for further developments of laser cleaning techniques.
Takahashi, Hiroki; Suzuki, Takahiro*; Ishiyama, Tatsuya*; Ito, Yuichi*
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.914 - 917, 2021/10
In the event of an abnormal situation, a machine protection system (MPS) that immediately inhibits the beam is indispensable to minimize the damage and the radioactivation by beam loss. The existing MPS was developed during the construction period, and there are many MPS modules that have been used from the beginning of J-PARC operation, Therefore, as a measure against aging, we started designing, manufacturing and updating the new MPS module in 2018. In this paper, the specifications and the results of performance test about the newly designed and manufactured the MPS signal aggregation module and the E/O converter module will be described.
Tamura, Fumihiko; Takahashi, Hiroki; Kamikubota, Norihiko*; Ito, Yuichi*; Hayashi, Naoki
IEEE Transactions on Nuclear Science, 68(8), p.2043 - 2050, 2021/08
Times Cited Count：0 Percentile：0.00(Engineering, Electrical & Electronic)A precise and stable timing system is necessary for high intensity proton accelerators such as the J-PARC. The existing timing system, which was developed during the construction period of the-PARC, has been working without major issues since 2006. After a decade of operation, the optical modules, which are key components for signal transfer, were discontinued already. Thus, the next-generation timing system for the J-PARC is under development. The new system is designed to be compatible with the existing system in terms of the operating principle. The new system utilizes modern high speed signal communication for the transfer of the clock, trigger, and type code. We present the system configuration of the next-generation timing system and current status.
Suzuki, Masaaki*; Ito, Mari*; Hashidate, Ryuta; Takahashi, Keita; Yada, Hiroki; Takaya, Shigeru
2020 9th International Congress on Advanced Applied Informatics (IIAI-AAI 2020), p.797 - 801, 2021/07
Toyota, Kodai; Hashidate, Ryuta; Takahashi, Keita; Yada, Hiroki; Takaya, Shigeru
Hozengaku, 20(2), p.95 - 103, 2021/07
