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Nakanoya, Takamitsu; Yoshimoto, Masahiro; Saha, P. K.; Takeda, Osamu*; Saeki, Riuji*; Muto, Masayoshi*
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.937 - 941, 2023/11
In the J-PARC 3GeV Rapid Cycling Synchrotron (RCS), the 400MeV H
beam is changed to H+ beam by a charge exchange foil and accelerated to 3GeV. So far, RCS had used two types of charge exchange foil. One is the HBC (Hybrid Boron mixed Carbon) foil and the other is the Kaneka GTF (Graphene Thin Film). HBC foil is a patented deposition method developed at KEK for the stable production of thick carbon foil. Initially, the RCS used HBC foil produced atKEK. However, in 2017, JAEA had started HBC foil production and has been using it since then. Recently, we have succeeded in depositing thick pure carbon foil, which had been considered difficult to produce by the arc deposition method. As a new challenge, this pure carbon foil was used in the user operation from March 2023. As a result, Pure carbon foils showed less deformation and more stable charge exchange performance than HBC and GTF.
Nakanoya, Takamitsu; Yoshimoto, Masahiro; Saha, P. K.; Takeda, Osamu*; Saeki, Riuji*; Muto, Masayoshi*
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.629 - 633, 2023/01
In the J-PARC 3-GeV Rapid Cycling Synchrotron (RCS), a 400 MeV H- beam injected from the linac is exchange to an H+ beam by a charge exchange foil and accelerated to 3 GeV. The charge exchange foils mainly used in the RCS are HBC foil (Hybrid Boron mixed Carbon stripper foil), which are made by adding a small amount of boron to carbon rods and using them as electrodes by the arc deposition method. Since 2018, foils produced by JAEA have been used for user operation. So far, no major problems have occurred due to the foils. Meanwhile, the beam power of the RCS has been gradually increased from 500 kW to 830 kW since 2018. As beam power increases, the foil issues were identified to achieve the RCS design power of 1 MW. In this paper, we will report on the recent foil usage status and issue in the user operation.
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.
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.
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.
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.
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 8.41
10
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.
Kinsho, Michikazu; Saito, Yoshio*; Kabeya, Zenzaburo*; Ogiwara, Norio
Vacuum, 81(6), p.808 - 811, 2007/02
Times Cited Count：7 Percentile：30.11(Materials Science, Multidisciplinary)It was success to develop alumina ceramics vacuum ducts for the 3GeV-RCS of J-PARC at JAERI. There are two types of alumina ceramics vacuum ducts needed, one being 1.5m-long duct with a circular cross section of 378 mm inner diamater for use in the quadrupole magnet, the other being 3.5m-long and bending 15 degrees, with a race-track cross section for use in the dipole magnet. These ducts could be manufactured by joining several duct segments of 0.8 m in length by brazing. The alumina ceramics ducts have copper stripes on the outside surface of the ducts to reduce the duct impedance. The radio-frequency shield is designed as a high frequency pass filter, where eddy currents cannot be generated. In this shield one end of each strope is connected to a titanium flange with a capacitor to interrupt the eddy current loop. With this, the impedance of the duct with the radio-frequency shield was reduced within an allowable desgin limit. In order to reduce emission of secondary electrons when protons or electrons strike the surface, TiN film is coated on the inside surface of the ducts.
Kinsho, Michikazu; Ogiwara, Norio; Saito, Yoshio*; Kabeya, Zenzaburo*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2604 - 2606, 2005/00
It was success to develop alumina ceramics vacuum ducts for the 3GeV-RCS of J-PARC at JAERI. There are two types of alumina ceramics vacuum ducts needed, one being 1.5m-long duct with a circular cross section for use in the quadrupole magnet, the other being 3.5m-long and bending 15 degrees, with a race-track cross section for use in the dipole magnet. These ducts could be manufactured by joining several duct segments of 0.5-0.8 m in length by brazing. The alumina ceramics ducts have copper stripes on the outside surface of the ducts to reduce the duct impedance. In order to reduce emission of secondary electrons when protons or electrons strike the surface, TiN film is coated on the inside surface of the ducts.
-ray irradiation experiments of collimator key components for the 3GeV-RCS of J-PARCKinsho, Michikazu; Ogiwara, Norio; Masukawa, Fumihiro; Takeda, Osamu; Yamamoto, Kazami; Kusano, Joichi
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.1309 - 1311, 2005/00
It was success to develop the radiation resistant components using for beam collimator. Turbo molecular pump could be operated more than 15 MGy of ray irradiation dose. Stepping motor developed at JAERI could be operated with good performance in the ray dose of more than 70 MGy. PEEK sheathed cables and connector have kept good performance during ray irradiation more than the dose of 10 MGy. It was cleared that the function of the heat pipe disappeared at 30 kGy ray irradiation dose.
Kinsho, Michikazu; Saito, Yoshio*; Nishizawa, Daiji*; Michizono, Shinichiro*
Journal of Nuclear Materials, 318, p.307 - 312, 2003/05
Times Cited Count：9 Percentile：53.35(Materials Science, Multidisciplinary)In order to choose an alumina ceramic material for use as a vacuum beam duct in a rapid cycling synchrotron, several kinds of alumina ceramics, having different microstructures, were examined under radiation fields of 2.5 MeV electrons. Since a long ceramic duct can only be manufactured by glazing duct segments, the mechanical strength and deterioration not only a ceramics but also in the glazing joint were measured after irradiation. These ceramic have a sufficiently high flexural strength which is more than 300 MPa before electron beam irradiation, and we could get the experimental results that there was no deterioration on the flexural strength of the ceramic after 1000 MGy electron beam irradiation. No noticeable changes could be seen in the measured tensile strength of Ti-ceramic brazed samples after 1000 MGy electron beam irradiation.
Kuramochi, Masaya*; Kinsho, Michikazu; Irie, Yoshiro*; Sugai, Isao*; Igarashi, Susumu*; Arakida, Yoshio*; Takeda, Yasuhiro*
Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.637 - 639, 2003/00
Three charge-exchange foils are used in J-PARC 3GeV Synchrotron(RCS). One is used for changing H to H
by stripping electrons, and the others are used for changing H
and H to H which are failed to strip at the first foil. In this paper, we will describe the temperature distribution at the charge-exchange foils calculated by a simulation code 'ANSYS' where the particle distribution is based on a particle tracking code 'ACCSIM'.
Yokomizo, Hideaki; 3GeV Ring Group
JAERI-Conf 2001-002, p.240 - 245, 2001/03
no abstracts in English
Zhang, F.; Tani, Norio; Shimada, Taihei; Suzuki, Hiromitsu; Yokomizo, Hideaki
Proceedings of 6th Symposium on Power Supply Technology for Accelerators, p.149 - 155, 2000/11
no abstracts in English
Yamamoto, Kazami; Hatakeyama, Shuichiro*
no journal, ,
The J-PARC 3-GeV Rapid Cycling Synchrotron (RCS) aims to deliver 1 MW proton beam to the materials and life science experimental facility (MLF) and the main ring synchrotron. In such a high intensity beam, there is a possibility to cause a severe radiation accident. To detect and prevent the radiation accident in the accelerator system, we developed the beam diagnostics system in RCS. This system includes a monitoring and interlock system of an abnormal state of the extraction beam to the mercury target of MLF. The radiation level of the gas in the tunnel were able to always observed by connecting radiation safety system and accelerator control system. Various kind of parameters, such as dump temperatures, radiation monitors, beam positions can be checked by one monitor to compare the influence each other.
