Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Ni and Zr at 0.4, 1.3, 2.2, and 3.0 GeVTakeshita, Hayato*; Meigo, Shinichiro; Matsuda, Hiroki*; Iwamoto, Hiroki; Nakano, Keita; Watanabe, Yukinobu*; Maekawa, Fujio
Nuclear Instruments and Methods in Physics Research B, 527, p.17 - 27, 2022/09
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)To improve accuracy of nuclear design of accelerator driven nuclear transmutation systems and so on, nuclide production cross sections on Ni and Zr were measured for GeV energy protons. The measured results were compared with PHITS calculations, JENDL/HE-2007 and so on.
Ono, Ayato; Takayanagi, Tomohiro; Sugita, Moe; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
JAEA-Technology 2021-044, 53 Pages, 2022/03
JAEA-Technology-2021-044.pdf:43.7MB
The 3-GeV rapid cycling synchrotron of Japan Proton Accelerator Research Complex (J-PARC) uses a large number of electromagnet power supplies in order to manipulate a high-intensity beam of 1 MW. These devices have been specially developed to meet the requirement to achieve acceleration of the 1-MW proton beams. Because J-PARC has been in operation for 10 years, we have to replace many parts and equipments due to failures caused by age-related deterioration. J-PARC accelerator system supplies the beams for many users, and we have to recover it as soon as possible when a trouble occurs. Therefore, if the trouble can be prevented before it happens, reduction of the user beam time can be minimized. Furthermore, it enables us to reduce additional work for operators. Maintenance is important to keep the equipments in a normal state, and makes it possible to extend the life of the equipments by detecting and maintaining the faulty parts and the aged deterioration parts at an early stage. Since all the devices requires the maintenance, there are a wide variety of maintenance methods. Some works are carried out by the J-PARC members, and some are performed by outsourcing. Ensuring safety and protecting workers are the most important issues in maintenance work. Therefore, J-PARC has rules for safety work. All workers in J-PARC have to learn and follow the rules. In addition, various ideas are being considered to enable safe and efficient work by devising ingenuity in each work. We also elaborate various ideas and processes for safe and efficient work according to the individual work conditions. In this report, we summarize the guideline and cautionary points during maintenance based on the actual case of maintenance and inspection work of the horizontal shift bump electromagnet power supply.
Lu target irradiated with 0.4-, 1.3-, 2.2-, and 3.0-GeV protonsTakeshita, Hayato; Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Hiroki; Nakano, Keita; Watanabe, Yukinobu*; Maekawa, Fujio
JAEA-Conf 2021-001, p.207 - 212, 2022/03
Prediction of nuclide production of spallation products by high-energy proton injection plays a fundamental and important role in shielding design of high-intensity proton accelerator facilities such as accelerator driven nuclear transmutation system (ADS). Since the prediction accuracy of the nuclear reaction models used in the production quantity prediction simulation is insufficient, it is necessary to improve the nuclear reaction models. We have measured nuclide production cross sections for various target materials with the aim of acquiring experimental data and improving nuclear reaction models. In this study, 1.3-, 2.2- and 3.0-GeV proton beams were irradiated to Lu target, and nuclide production cross-section data were acquired by the activation method. The measured data were compared with several nuclear reaction models used in Monte Carlo particle transport calculation codes to grasp the current prediction accuracy and to study how the nuclear reaction model could be improved.
Ono, Ayato; Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
JAEA-Technology 2021-005, 40 Pages, 2021/05
JAEA-Technology-2021-005.pdf:4.27MB
The 3-GeV rapid cycling synchrotron of Japan Proton Accelerator Research Complex (J-PARC) uses a large number of electromagnet power supplies in order to manipulate a high-intensity beam of 1 MW. These devices have been specially developed to meet the requirement to achieve acceleration of the 1-MW proton beams. State-of-the-art technologies are used to these devices. To achieve stable operation with few failures, and to prevent major troubles in the event of a failure, it is necessary to maintain the performance of the devices under the appropriate and accurate management strategy with an enough understanding of its characteristics. However, since the specification and function of each device is different respectively, and it is also produced by different manufacturer, we have to maintain adequately according to the structure, configuration and features of the apparatus. There are typically three major stages in the maintenance works. First, "Daily inspection" is constantly performed to monitor the status of the equipment during operation and check for any errors or abnormalities. Second, "Routine maintenance" is carried out weekly, monthly, or yearly to fix the errors, or to replace the parts that are deteriorated. Third, "Troubleshooting" is conducted to recover from sudden failures. In this report, we will introduce the specific contents of "Routine maintenance", "Daily inspection", and "trouble case" based on the experiences of the electromagnet power supply group. In particular, we will report the work management methods, including ideas for facilitating recovery work. We will also summarize the important points of a matter that does not depend on the configuration, structure, and characteristics of the equipment.
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*
JPS Conference Proceedings (Internet), 33, p.011050_1 - 011050_6, 2021/03
R&D of the beam window is crucial in the ADS, which serves as a partition between the accelerator and the target region. Although the displacement per atom (DPA) is used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and aluminum and copper was used as samples. As a result of comparison between the present experiment and the calculation of the NRT model, which is widely used for calculation of the displacement cross section, it was found that the calculation of the NRT model overestimated the experiment by about 3 times.
Takeshita, Hayato; Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Hiroki; Maekawa, Fujio; Watanabe, Yukinobu*
JPS Conference Proceedings (Internet), 33, p.011045_1 - 011045_6, 2021/03
To improve accuracy of nuclear design of accelerator driven nuclear transmutation systems, nuclide production cross sections on Ni and Zr, which were candidate materials to be used in ADS, were measured for GeV energy protons. The measured results were compared with PHITS calculations and JENDL/HE-2007.
Ono, Ayato; Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
JAEA-Technology 2020-023, 40 Pages, 2021/02
JAEA-Technology-2020-023.pdf:2.98MB
The 3 GeV rapid cycling synchrotron of Japan Proton Accelerator Research Complex (J-PARC) uses a large number of electromagnet power supplies in order to generate a high-intensity beam of 1 MW. These devices have been specially developed to meet the required specifications of the proton beams. Ten years have passed since the 3 GeV synchrotron had started operation, and we need to replace and update of the components due to failures caused by the aging deterioration. Since the J-PARC is used by many users, it is quite important to recover as soon as possible when a trouble occurs. However, we often spend lots of time to investigate the status and cause of the problem, then it results in the delay of recovery work. One of the major reasons is due to the differences in the manufacturers of sensors and monitors. Therefore, we have to create a manual for each power supply and prepare some exclusive tools. However, troubles rarely occur in the same state and situation, so we have to rely on the experience and knowledge. Even for power supplies with different purposes and specifications, some components, such as sensors, can be shared in many cases. In addition, if the concept of the interlock system, for monitoring the status of the power supply and detecting malfunctions, is shared between the different power supplies, the method and response for failure investigation can be standardized. By using a device with good maintainability, the accelerator operation will be more stable and reliable. In this report, we introduce the necessity of sharing the design concept and common parts. We also explain the basic design model for safety and reliability, using an example of manufacturing an electromagnet power supply for the 3 GeV synchrotron.
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*
EPJ Web of Conferences, 239, p.06006_1 - 06006_4, 2020/09
Times Cited Count：0 Percentile：0.1R&D of the beam window is crucial in the ADS, which serves as a partition between the accelerator and the target region. Although the displacement per atom (DPA) is used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and copper was used as samples. As a result of comparison between the present experiment and the calculation of the NRT model, which is widely used for calculation of the displacement cross section, it was found that the calculation of the NRT model overestimated the experiment by about 3 times.
Aritomo, Yoshihiro*; Amano, Shota*; Okubayashi, Mizuki*; Yanagi, Baku*; Nishio, Katsuhisa; Ota, Masahisa*
Physics of Atomic Nuclei, 83(4), p.545 - 549, 2020/07
Times Cited Count：0 Percentile：0.02(Physics, Nuclear)Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*
JPS Conference Proceedings (Internet), 28, p.061004_1 - 061004_6, 2020/02
no abstracts in English
Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki
Journal of Nuclear Science and Technology, 55(8), p.955 - 961, 2018/08
Times Cited Count：3 Percentile：35.39(Nuclear Science & Technology)We have started an experimental program to measure activation cross sections systematically in the proton-induced spallation reaction in structural materials commonly used in high-intensity proton accelerator-based facilities, such as Japan Proton Accelerator Research Complex (J-PARC). As the first step of the program, aluminum (Al) was chosen to verify the adequacy of the measurement technique implemented in a J-PARC proton beam environment because data of Al have been relatively well studied both by experimental measurement and simulation. Activation cross sections of 
Be, 
Na, and 
Na in Al were measured at proton energy points from 0.4, 1.3, 2.2 to 3.0 GeV, which could be delivered smoothly from the synchrotron. The validity of experimental data has been verified by introducing an effective proton numbers determination procedure. We compared the measured data with existing experimental data, the evaluated data (JENDL-HE/2007), and the calculations with several intra-nuclear cascade models by the Particle and Heavy Ion Transport code System (PHITS) code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated about 40%. This could come from the evaporation model (generalized evaporation model) being implemented in the PHITS code. We found that the calculations agreed with the experimental data by an upgraded PHITS code.
Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki
Journal of Physics; Conference Series, 1021(1), p.012017_1 - 012017_4, 2018/06
Times Cited Count：0 Percentile：0.11Spallation neutron at 180 degrees is of important for an evaluation of radiation protection for ADS (Accelerator-Driven System) and the nuclear physics. It was, however, quite difficult to measure it. We measured the energy spectrum of spallation neutron at 180 degrees at the proton transport beam line (3NBT) to MLF (Materials and Life Science Experimental Facility) on J-PARC by the NE213 liquid scintillator. The irradiated proton energy was 3 GeV, and the intensity was 1
10
protons above. The neutron energy was determined by Time-Of-Flight method with n-gamma discrimination. We also simulated the energy spectrum by using PHITS code and compared with measured spectrum. In this paper, the overview of the experiment and the results are described.
Yamamoto, Kazami; Saha, P. K.
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.1045 - 1047, 2018/06
The 3 GeV rapid cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) provides more than 500 kW beams to the Material and Life Science Facility (MLF) and Main Ring (MR). In such a high-intensity hadron accelerator, even losing less than 0.1% of the beam can cause many problems. Such lost protons can cause serious radio-activation and accelerator component malfunctions. Therefore, we have conducted a beam study to achieve high-power operation. In addition, we have also maintained the accelerator components to enable stable operation. This paper reports the status of the J-PARC RCS over the last two years.
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Iwamoto, Hiroki; Hasegawa, Shoichi; Maekawa, Fujio; Yoshida, Makoto*; Ishida, Taku*; Makimura, Shunsuke*; Nakamoto, Tatsushi*
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.499 - 501, 2018/06
no abstracts in English
Yamamoto, Kazami
EPJ Web of Conferences, 153, p.07022_1 - 07022_6, 2017/09
Times Cited Count：1 Percentile：63.37The J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) delivers a 1-MW, high-intensity beam to the following facilities. In such high-intensity accelerator, the operational beam intensity is limited to keep the exposure to the workers by the residual dose within acceptable tolerances. Therefore we continue to commission the accelerator system to reduce the beam loss. In order to achieve further high-intensity operation, the J-PARC accelerator system was drastically upgraded (Increment of the injection energy of RCS and peak current of Linac) over the past two years. After the upgrade, the beam loss was decreased by the commissioning. The output power was increased; nevertheless the residual doses were kept same level or decreased. Since we replaced the broken collimator which was higher activated, we kept the exposure to the workers within acceptable level.
Takada, Hiroshi; Haga, Katsuhiro; Teshigawara, Makoto; Aso, Tomokazu; Meigo, Shinichiro; Kogawa, Hiroyuki; Naoe, Takashi; Wakui, Takashi; Oi, Motoki; Harada, Masahide; et al.
Quantum Beam Science (Internet), 1(2), p.8_1 - 8_26, 2017/09
At the Japan Proton Accelerator Research Complex (J-PARC), a pulsed spallation neutron source provides neutrons with high intensity and narrow pulse width to promote researches on a variety of science in the Materials and life science experimental facility. It was designed to be driven by the proton beam with an energy of 3 GeV, a power of 1 MW at a repetition rate of 25 Hz, that is world's highest power level. A mercury target and three types of liquid para-hydrogen moderators are core components of the spallation neutron source. It is still on the way towards the goal to accomplish the operation with a 1 MW proton beam. In this paper, distinctive features of the target-moderator-reflector system of the pulsed spallation neutron source are reviewed.
Oi, Motoki; Meigo, Shinichiro; Akutsu, Atsushi*; Kawasaki, Tomoyuki; Nishikawa, Masaaki*; Fukuda, Shimpei
Proceedings of 12th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '15), p.89 - 96, 2016/00
At J-PARC, 3 GeV proton beam with power of 1MW is delivered to the spallation neutron source (JSNS) through beam transport line called 3NBT. At the high power accelerator facilities even a small abnormal event has a possibility to be critical so that the beam control system is crucial. In order to find tiny anomaly, rapid data analysis system is required. We developed control and data analysis system based on the Experimental Physics and Industrial Control System (EPICS) and Control System Studio (CSS). To carry out beam tuning efficiently, the beam control system based on the Strategic Accelerator Design (SAD) code has been developed. With the several shots of beam and by the one click of operational panel of the screen, required magnet field can be calculated and set automatically. Also we developed automated e-mail system to announce the abnormal event to the experts persons. With these systems, we can reduce both beam tuning time and down time.
Kinsho, Michikazu
Proceedings of 6th International Particle Accelerator Conference (IPAC '15) (Internet), p.3798 - 3800, 2015/06
Beam power of routine operation of the J-PARC rapid cycling synchrotron (RCS) increased gradually for the MLF user operation, beam power of 400 kW was achieved on 10th March, and 500 kW user operation has been stably performed from 14th April this year. Beam studies were also performed to demonstrate the capability of the RCS to operate at powers in excess of 1 MW. The study produced a beam intensity of 8.4110
protons during short time, an intensity equivalent to 1.01 MW operation on 10th January 2015. In this beam study it was cleared issues to realize 1MW operation in the RCS. Status of user operation and issues to realize high power operation in the RCS are presented.
Yamamoto, Kazami; Hayashi, Naoki; Okabe, Kota; Harada, Hiroyuki; Saha, P. K.; Yoshimoto, Masahiro; Hatakeyama, Shuichiro; Hotchi, Hideaki; Hashimoto, Yoshinori*; Toyama, Takeshi*
Proceedings of 54th ICFA Advanced Beam Dynamics Workshop on High-Intensity, High Brightness and High Power Hadron Beams (HB 2014) (Internet), p.278 - 282, 2015/03
Rapid Cycling Synchrotron (RCS) of Japan Proton Accelerator Complex (J-PARC) is providing more than 300 kW of proton beam to Material and Life science Facility (MLF) and Main Ring (MR). Last summer shutdown, a new ion source was installed to increase output power to 1 MW. In order to achieve reliable operation of 1 MW, we need to reduce beam loss as well. Beam quality of such higher output power is also important for users. Therefore we developed new monitors that can measure the halo with higher accuracy. We present beam monitor systems for these purposes.
Kinsho, Michikazu
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.3382 - 3384, 2014/07
Big issue for the J-PARC rapid cycling synchrotron (RCS) was displacement of main magnets caused by last big earthquake because this made beam loss more than 400 kW beam power. Since realignment of main magnets and other components was essential to realize higher beam power and stable operation, this work has been done during maintenance period in 2013. To achieve the nominal performance 1MW beam power at the RCS and 0.75 MW at the MR, beam energy of linac was increased from 181 MeV to 400 MeV with a new accelerating structure ACS (Annular-ring Coupled Structure) linac from this January. It was successful 400 MeV beam injection and 3 GeV beam extraction at the RCS, and user operation has been performed with beam power of 300 kW. An equivalent beam power of 560 kW with a beam loss of only 0.3% could be achieved during short time for high intensity beam study.
