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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：6 Percentile：84.97(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.
Yang, M.*; Kamikubota, Norihiko*; Sato, Kenichi*; Kikuzawa, Nobuhiro; Tajima, Yuto*
Proceedings of 18th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2021) (Internet), p.927 - 930, 2022/02
Since 2006, the Japan Proton Accelerator Research Complex (J-PARC) timing system has been operated successfully. However, there were some unexpected trigger-failure events, typically missing trigger events, during the operation over 15 years. When a trigger-failure event occurred, it was often tough to find the one with the fault among many suspected modules. To solve the problem more easily, a unique device, triggered scaler, was developed for reading back accelerator signals. The performance of the module has been evaluated in 2018. In 2021, we measured and observed an LLRF signal as the first signal of the read-back system for beam operation. After firmware upgrades of the module, some customized timing read-back systems were developed, and successfully demonstrated as coping strategies for past trigger-failure events. In addition, a future plan to apply the read-back system to other facilities is discussed. More details are given in the paper.
Yang, M.*; Kamikubota, Norihiko*; Tajima, Yuto*; Sato, Kenichi*; Kikuzawa, Nobuhiro
Proceedings of 22nd Virtual IEEE Real Time Conference (Internet), 5 Pages, 2020/10
During the operation of J-PARC timing system since 2006, there were a few unexpected trigger-failure events occurred. It was difficult to find the faulty module among many suspicious modules. In order to find such a module easily, a Yokogawa PLC-type triggered scaler module was developed. It can accept the start of J-PARC Main Ring (MR) slow cycle (2.48s/5.2s) signal and the start of rapid cycle (25Hz) signal, which are generated by J-PARC timing system. A scaler in the module counts number of trigger pulses during the J-PARC slow cycle and stores counts in an array. In 2018, the module was tested successfully and the results showed the expected performance. The details of the module and two associated applications will be described in the paper.
Kondo, Yasuhiro; Hirano, Koichiro; Ito, Takashi; Kikuzawa, Nobuhiro; Kitamura, Ryo; Morishita, Takatoshi; Oguri, Hidetomo; Okoshi, Kiyonori; Shinozaki, Shinichi; Shinto, Katsuhiro; et al.
Journal of Physics; Conference Series, 1350, p.012077_1 - 012077_7, 2019/12
Times Cited Count：1 Percentile：52.28(Physics, Particles & Fields)We have upgraded a 3-MeV linac at J-PARC. The ion source is same as the J-PARC linac's, and the old 30-mA RFQ is replaced by a spare 50-mA RFQ, therefore, the beam energy is 3 MeV and the nominal beam current is 50 mA. The main purpose of this system is to test the spare RFQ, but also used for testing of various components required in order to keep the stable operation of the J-PARC accelerator. The accelerator has been already commissioned, and measurement programs have been started. In this paper, present status of this 3-MeV linac is presented.
Kikuzawa, Nobuhiro; Niki, Kazuaki*; Yamamoto, Noboru*; Hayashi, Naoki; Adachi, Masatoshi*; Watanabe, Kazuhiko*
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.877 - 880, 2019/07
Interlock system of J-PARC is classified into a personnel protection system (PPS) for human safety and a machine protection system (MPS) for protecting equipment. The PPS of the J-PARC accelerator started from the operation at Linac in 2006 and was completed by the MR operation in 2008. In the next 10 years, some improvements have been made, such as updating video monitoring systems and establishing new interlocks. In addition to describing recent operations including these updatings, this paper reports the current status of inspections and maintenance conducted to maintain and improve reliability.
Kamikubota, Norihiko*; Yamada, Shuei*; Sato, Kenichiro*; Kikuzawa, Nobuhiro; Yamamoto, Noboru*; Yoshida, Susumu*; Nemoto, Hiroyuki*
Proceedings of 16th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2017) (Internet), p.1470 - 1473, 2018/01
no abstracts in English
Hayashi, Naoki; Kikuzawa, Nobuhiro; Miura, Akihiko; Futatsukawa, Kenta*; Miyao, Tomoaki*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.540 - 544, 2017/12
The J-PARC linac operation is stable, however, the numbers of interlocked events due to single beam loss monitor (BLMP) is increasing. Recently, the counts is comparable to the number of RFQ trip, and a measure has been required for improvement of the operation efficiency. Thus, every event data has been analyzed and classified into three categories. It is found that there are characteristic signal or pattern of BLMP for every categories. Although the linac BLMP detector is standard, its setting parameters are differ from those of other two synchrotrons in the J-PARC. To optimize time resolution, the input impedance of its pre-amplifier is selected to be 50 
and interlock is defined in raw signal height and width not integral signal of BLMP. Some new parameters has been tried to reduce unnecessary interlock.
Kondo, Yasuhiro; Asano, Hiroyuki*; Chishiro, Etsuji; Hirano, Koichiro; Ishiyama, Tatsuya; Ito, Takashi; Kawane, Yusuke; Kikuzawa, Nobuhiro; Meigo, Shinichiro; Miura, Akihiko; et al.
Proceedings of 28th International Linear Accelerator Conference (LINAC 2016) (Internet), p.298 - 300, 2017/05
We have constructed a linac for development of various accelerator components at J-PARC. The ion source is same as the J-PARC linac's, and the RFQ is a used one in the J-PARC linac. The beam energy is 3 MeV and nominal beam current is 30 mA. The accelerator has been already commissioned, and the first development program, laser-charge-exchange experiment for the transmutation experimental facility, has been started. In this paper, present status of this 3-MeV linac is presented.
Ikeda, Hiroshi; Kikuzawa, Nobuhiro; Yoshii, Akinobu*; Kato, Yuko
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.637 - 640, 2016/11
no abstracts in English
Sawabe, Yuki*; Ishiyama, Tatsuya; Takahashi, Daisuke; Kato, Yuko; Suzuki, Takahiro*; Hirano, Koichiro; Takei, Hayanori; Meigo, Shinichiro; Kikuzawa, Nobuhiro; Hayashi, Naoki
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.647 - 651, 2016/11
In the J-PARC, a 3 MeV linac has been developed for the tests of beam scraper irradiation and charge exchange by high-power laser. To accomplish tests efficiently and safely, the control system for 3 MeV was designed and developed, and this system consists of four subsystems, personal protection system, machine protection system, timing system, and remote control system using the EPICS. In this paper, the details of control system for a 3 MeV linac are presented.
Hirano, Koichiro; Asano, Hiroyuki; Ishiyama, Tatsuya; Ito, Takashi; Okoshi, Kiyonori; Oguri, Hidetomo; Kondo, Yasuhiro; Kawane, Yusuke; Kikuzawa, Nobuhiro; Sato, Yoshikatsu; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.310 - 313, 2016/11
We have used a beam scraper with the incident angle of 65deg to reduce the beam power deposition density in the MEBT between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC linac. The 65
scraper was irradiated by the H
beam up to particle number of 1.47E22. We observed a lot of surface projections with several hundred micrometers high in the beam irradiation damage on the scraper by using the laser microscope. In order to study the limits of scrapers, we constructed a new 3 MeV linac at J-PARC. We will conduct the scraper irradiation test at the end of this year.
Kamikubota, Norihiko*; Kikuzawa, Nobuhiro; Tamura, Fumihiko; Yamamoto, Noboru*
Proceedings of 15th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2015) (Internet), p.988 - 991, 2016/01
The beam commissioning of J-PARC started in November, 2006. Since then, the timing system of J-PARC accelerator complex has contributed stable beam operations of three accelerators: a 400-MeV linac (LI), a 3-GeV rapid cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The timing system handles two different repetition cycles: 25 Hz for LI and RCS, and 2.48-6.00 sec. for MR (MR cycle). In addition, the timing system is capable to provide beams to two different experimental facilities in single MR cycle: Material and Life Science Experimental Facility (MLF) and Neutrino Experimental Facility (NU), or, MLF and Hadron Experimental Facility (HD). Recently, a plan to introduce a new facility, Accelerator-Driven Transmutation Experimental Facility (ADS), around 2018, has been discussed. This paper reviews the 8-year operation experience of the J-PARC timing system, followed by a present perspective of upgrade studies.
Kikuzawa, Nobuhiro; Ikeda, Hiroshi; Kato, Yuko; Yoshii, Akinobu*
Proceedings of 15th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2015) (Internet), p.818 - 821, 2016/00
J-PARC (Japan Proton Accelerator Research Complex) consists of much equipment. In Linac and 3 GeV rapid cycling synchrotron ring (RCS), the data of over the 64,000 EPICS records for these equipment has been collected. The Data volume will be about 10 TB in 2020. The data have been being stored by a Relational Data Base (RDB) system using PostgreSQL, but it is not enough in availability, performance, and capability to increase of data volume flexibility. Hadoop/HBase, which is known as a distributed, scalable and big data store, has been proposed for our next-generation archive system to solve these problems. The archiving system was built and verified about data transition or database utilization. This report shows the result of the modification of the archive system.
Sawabe, Yuki; Maruta, Tomofumi*; Liu, Y.*; Miura, Akihiko; Miyao, Tomoaki*; Ishiyama, Tatsuya; Kikuzawa, Nobuhiro; Hayashi, Naoki
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1202 - 1205, 2015/09
no abstracts in English
Ikeda, Hiroshi; Kikuzawa, Nobuhiro; Yoshii, Akinobu*; Kato, Yuko
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1312 - 1316, 2015/09
The Linac and the RCS in J-PARC provide enormous operation data and we have been stored them into PostgreSQL. We are planning to replace it with HBase, a data store specialized for big-data and is on a distributed file system provided by Hadoop, using a cluster with advantages including automatically recovering and easily extending the capacity. In the previous presentation we reported we updated HBase/Hadoop in our test system and we showed issues to fix our tools in the new system, while we also mentioned issues about the construction of our cluster itself. In this presentation we are reporting we have re-designed and re-constructed the cluster with resolving the issues, including enhancing hardware of master nodes, creating automatic scripts to construct nodes, and introducing monitoring tools for nodes. Having accordingly adjusted the configurations of HBase/Hadoop and measured the performance of our new system, we are also reporting its results and considerations.
, ') reaction of 
U on the target thicknessNegm, H.*; Ogaki, Hideaki*; Daito, Izuru*; Hayakawa, Takehito; Zen, H.*; Kii, Toshiteru*; Masuda, Kai*; Hori, Toshitada*; Hajima, Ryoichi; Shizuma, Toshiyuki; et al.
Journal of Nuclear Science and Technology, 52(6), p.811 - 820, 2015/06
Times Cited Count：4 Percentile：33.25(Nuclear Science & Technology)The dependence of the nuclear resonance fluorescence (NRF) yield on the target thickness was studied. To this end, an NRF experiment was performed on U using a laser Compton back-scattering (LCS) -ray beam at the High Intensity -ray Source facility at Duke University.
Kikuzawa, Nobuhiro; Ikeda, Hiroshi; Kato, Yuko; Ouchi, Nobuo; Yoshii, Akinobu*
Proceedings of 10th International Workshop on Personal Computers and Particle Accelerator Controls (PCaPAC 2014) (Internet), p.193 - 195, 2015/02
J-PARC (Japan Proton Accelerator Research Complex) consists of much equipment. In Linac and 3 GeV rapid cycling synchrotron ring (RCS), the data of over the 64,000 EPICS records for these equipment has been collected. The Data volume is about 2 TB in every year, and the stored total data volume is about 10 TB. The data have been being stored by a Relational Data Base (RDB) system using PostgreSQL, but it is not enough in availability, performance, and capability to increase of data volume flexibility. Hadoop/HBase, which is known as a distributed, scalable and big data store, has been proposed for our next-generation archive system to solve these problems. The test system was built and verified about data transition or database utilization. This report shows the current status of the new archive system, and its advantages and problems which have been obtained through our verification.
Kondo, Yasuhiro; Morishita, Takatoshi; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Chishiro, Etsuji; Fukuda, Shimpei; Hasegawa, Kazuo; Hirano, Koichiro; Kikuzawa, Nobuhiro; et al.
Physical Review Special Topics; Accelerators and Beams, 17(12), p.120101_1 - 120101_8, 2014/12
Times Cited Count：6 Percentile：42.9(Physics, Nuclear)We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.
Kikuzawa, Nobuhiro; Ikeda, Hiroshi; Yoshii, Akinobu*; Kato, Yuko; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.794 - 798, 2014/10
no abstracts in English
Sawabe, Yuki; Ito, Yuichi; Kawase, Masato; Fukuta, Shimpei; Suzuki, Takahiro*; Kikuzawa, Nobuhiro; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.748 - 751, 2014/10
no abstracts in English
