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Journal Articles

Improvement of the J-PARC operation data archiver using HBase/Hadoop

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.

Journal Articles

Preliminary test of injection tuning using an emittance and acceptance measurement system at the JAEA AVF cyclotron

Kashiwagi, Hirotsugu; Miyawaki, Nobumasa; Kurashima, Satoshi; Okumura, Susumu

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.703 - 705, 2015/09

no abstracts in English

Journal Articles

Precise current adjustment of the power supply for the injection painting magnets in the J-PARC RCS

Kato, Shinichi; Takayanagi, Tomohiro; Harada, Hiroyuki; Horino, Koki; Tobita, Norimitsu; Ueno, Tomoaki*; Kinsho, Michikazu

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1180 - 1184, 2015/09

For the high intensity proton accelerator, the mitigation of the space charge force is most important because it causes the beam loss. For mitigation, the painting injection method which arranges the injection beam on the wide phase-space area during the multi-turn injection has been performed to expand the circulating beam in the J-PARC RCS. In the horizontal plane, the position and angle of the injection beam are fixed and these of the circulating beam are changed during the painting injection. Specifically, the time variation of the bump orbit height at the injection point is generated by the 4 paint bump magnet whose power supply are separate. Hence, the accuracy of the painting injection depend on the power conditioning precision of the magnet power supply. Therefore, the output characteristics of the power supply was examined for the precise power conditioning. In addition, the automatic conditioning tool has been developed based on that results.

Journal Articles

Status of J-PARC 3 GeV rapid cycling synchrotron under the high power operation

Yamamoto, Kazami; Kinsho, Michikazu

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.377 - 381, 2015/09

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. While the energy and the peak current of J-PARC linac had been increased in 2013 and 2014, preparations of RCS for 1 MW operation were also arranged. As a result of the injection energy upgrade in 2013, we confirmed that the space charge effect during acceleration process was well eased and the beam loss was drastically reduced. After increment of the peak current from the linac, we tried 1 MW-equivalent operation. This first trial revealed that the power supply of the RF cavity was insufficient to accelerate 1 MW-equivalent beam. The RF system was improved at the end of 2014, and 1 MW-equivalent beam operation was achieved in January, 2015. The beam power for MLF users was also increased to 500 kW in April. In this paper, we report the improvement and status of RCS for high power operation.

Journal Articles

Present status of JAEA-Tokai tandem accelerator and booster

Matsuda, Makoto; Osa, Akihiko; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Nakamura, Masahiko; Kutsukake, Kenichi; Otokawa, Yoshinori; et al.

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.357 - 360, 2015/09

no abstracts in English

Journal Articles

Improvement of the vacuum pressure of the bunch shape monitor at J-PARC linac

Miyao, Tomoaki*; Miura, Akihiko; Kawane, Yusuke; Tamura, Jun; Nemoto, Yasuo; Ao, Hiroyuki*; Hayashi, Naoki; Oguri, Hidetomo; Ouchi, Nobuo; Mayama, Minoru*; et al.

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1338 - 1341, 2015/09

no abstracts in English

Journal Articles

Present status of the injector for IFMIF Linear Prototype Accelerator (LIPAc)

Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Hiroki; Kondo, Keitaro; Kasugai, Atsushi; Gobin, R.*; Sen$'e$e, F.*; Chauvin, N.*; Ayala, J.-M.*; Marqueta, A.*; et al.

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.493 - 495, 2015/09

Development of the prototype accelerator (LIPAc) for the engineering validation of the International Fusion Materials Irradiation Facility (IFMIF) which is an accelerator driven neutron source has been progressed at Rokkasho. The LIPAc is a deuteron linear accelerator consisting of an injector, a radio-frequency quadrupole (RFQ) linac and a superconducting linac. The objective of LIPAc is to produce a CW beam with the energy and current of 9 MeV and 125 mA, respectively. The injector was developed at CEA/Saclay and succeeded to produce CW proton and deuteron beams of 100 keV/140 mA by autumn 2012. After the test at CEA/Saclay, the injector was shipped to the International Fusion Energy Research Centre (IFERC) in Rokkasho, Aomori and started to reassemble from the end of 2013. It was successfully produced proton beams in November 2014 at Rokkasho. While the ion source conditioning was done, the beam test was progressed. In this paper, the present status of the LIPAc injector at Rokkasho with some experimental results will be presented.

Journal Articles

Development of a 250 kV photogun for high current operation

Nishimori, Nobuyuki; Nagai, Ryoji; Sawamura, Masaru; Hajima, Ryoichi

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.508 - 510, 2015/09

no abstracts in English

Journal Articles

Status and upgrade plan of the cERL gun

Nishimori, Nobuyuki; Nagai, Ryoji; Mori, Michiaki; Hajima, Ryoichi; Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Uchiyama, Takashi*; Jin, X.*; Obina, Takashi*; et al.

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.511 - 515, 2015/09

no abstracts in English

Journal Articles

Investigation of phosphor materials for the real-time measurement of the transverse intensity distribution of large-area ion beams at the JAEA AVF cyclotron facility

Yuri, Yosuke; Yuyama, Takahiro; Ishizaka, Tomohisa; Koka, Masashi; Yamada, Naoto

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.420 - 423, 2015/09

no abstracts in English

Journal Articles

Development of high power baluns using MA cores, 2

Tamura, Fumihiko; Shimada, Taihei; Yoshii, Masahito*; Omori, Chihiro*; Yamamoto, Masanobu; Nomura, Masahiro; Toda, Makoto*; Hasegawa, Katsushi*; Hara, Keigo*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.639 - 642, 2015/09

In the J-PARC RCS, magnetic alloy (MA) loaded rf cavities are employed to achieve a high accelerating voltage and to realize the dual harmonic operation, where a single cavity is driven by the fundamental accelerating rf and the second harmonic. The cavity is driven by a class-AB push-pull tetrode amplifier. R&D for a high power balun to mitigate the unbalanced output voltages of two tubes is undergoing. The balun is a rf transformer, which consists of a MA core and high voltage cables. In application to the RCS rf system, the maximum rf voltage is very high in the order of 15kV and suppression of corona dischages is a key. We presentthe techniques to suppress corona discharges. Also, the R&D status of cooling of the MA core and cables.

Journal Articles

Beam loss mitigation by the modification of the beam pulse definition in the J-PARC LINAC

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

Journal Articles

Generation and applications of laser Compton scattered $$gamma$$-ray beams

Hajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Nishimori, Nobuyuki; Hayakawa, Takehito; Shizuma, Toshiyuki; Angell, C.

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.79 - 83, 2015/09

Generation of energy-tunable narrow-bandwidth $$gamma$$-rays via Laser Compton Scattering (LCS) is of great interest for scientific studies and applications of MeV photons which interact with nuclei. We are developing technologies relevant to generation of high-brightness LCS $$gamma$$-ray beams. One of the promising applications of such $$gamma$$-rays is the nondestructive detection and assay of nuclides which are necessary for nuclear security and safeguards. We summarize R-and-D status of LCS $$gamma$$-ray sources and overview future applications.

Journal Articles

High-power tests of RF input coupler for the IFMIF/EVEDA RFQ prototype linac

Maebara, Sunao; Sukegawa, Keiichi*; Tadano, Shuya*; Kasugai, Atsushi; Suzuki, Hiromitsu; Abe, Kazuhiko*; Oku, Ryuji*; Sugimoto, Masayoshi

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1140 - 1142, 2015/09

For the IFMIF/EVEDA accelerator prototype RFQ linac, the operation frequency of 175MHz was selected to accelerate a large current of 125mA. The driving RF power of 1.28MW by 8 RF input couplers has to be injected to the RFQ cavity for CW operation mode. For each RF input coupler, nominal RF power of 160kW and maximum transmitted RF power of 200kW are required. For this purpose, an RF input coupler with cooling functions was designed, based on a 6 1/8 inch co-axial waveguide, and the RF coupler was manufactured by way of trial. For the trial RF coupler, high-power tests using a high voltage standing wave on a high-Q load circuit wave were carried out, and a 200kW-14 sec CW operation were performed after four days of RF aging. No RF contact defects, unnecessary low-Q value and extraordinary outgassing were observed. This report describes the high-power tests of the RF input coupler.

Journal Articles

Demonstration of laser Compton-scattered photon source at the cERL

Nagai, Ryoji; Hajima, Ryoichi; Shizuma, Toshiyuki; Mori, Michiaki; Akagi, Tomoya*; Kosuge, Atsushi*; Honda, Yosuke*; Araki, Sakae*; Terunuma, Nobuhiro*; Urakawa, Junji*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1328 - 1330, 2015/09

Accelerator and laser technologies required for laser Compton scattering (LCS) photon source based on an energy-recovery linac (ERL) have been developed at the Compact ERL (cERL) facility. A high-flux, energy tunable, and monochromatic photon source such as the ERL-based LCS photon source is necessary for nondestructive assay of nuclear materials. For the demonstration of the ERL-based LCS photon generation, a laser enhancement cavity was installed at the recirculation loop of the cERL. The electron beam energy, the laser wavelength, and the collision angle are 20 MeV, 1064 nm, and 18 $$^{circ}$$, respectively. The calculated maximum energy of the LCS photons is about 7 keV. A silicon drift detector (SDD) with active area of 17 mm$$^{2}$$ placed 16.6 m from the collision point was used for observation of the LCS photons. As a result of the measurement, the flux on the detector, central energy, and energy width of the LCS photons were obtained as 1200/s, 6.91 keV, and 81 eV, respectively.

Journal Articles

Development of bunch shape monitor at J-PARC Linac

Futatsukawa, Kenta*; Kawane, Yusuke; Tamura, Jun; Nemoto, Yasuo; Hayashi, Naoki; Fukuoka, Shota*; Mayama, Minoru*; Miura, Akihiko; Miyao, Tomoaki*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1246 - 1250, 2015/09

no abstracts in English

Journal Articles

Optics model determination for Beam-Based Alignment of the J-PARC RCS

Hayashi, Naoki; Hotchi, Hideaki; Harada, Hiroyuki

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1206 - 1209, 2015/09

Beam-Based Alignment of BPM is indispensable procedure to determine accurate offset of quadrupole magnet nearby. In the J-PARC RCS, its quadrupole magnets cannot be controlled their current individually. Because the precise optics model is already available, one can calculate absolute beam position inside the quadrupole magnet based on the model. Comparing the predicted value and measured position, one can determine the offset, namely performing BBA. Using all COD data, kicked by all steering magnets, one can emulate a local bump orbit at the quadrupole magnet (QM). By changing focusing force of the QM, one can record the modification of the orbit and it is directly related to the original model. In this paper, we carry it out about one of seven QM family and report the comparison between the obtained results and the optics model.

Journal Articles

Recent progress of beam study in the J-PARC linac

Maruta, Tomofumi*; Liu, Y.*; Futatsukawa, Kenta*; Miyao, Tomoaki*; Miura, Akihiko; Ikegami, Masanori*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.432 - 436, 2015/09

no abstracts in English

Journal Articles

Development of a proton accelerator for OIST BNCT

Kondo, Yasuhiro; Hasegawa, Kazuo; Higashi, Yasuo*; Kumada, Hiroaki*; Kurokawa, Shinichi*; Matsumoto, Hiroshi*; Naito, Fujio*; Yoshioka, Masakazu*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.948 - 950, 2015/09

An accelerator based boron neutron capture therapy (BNCT) facility is being planned at Okinawa institute of science and technology (OIST). The proton accelerator consists of a radio frequency quadrupole (RFQ) linac and a drift tube linac (DTL). The reqired beam power is 60 kW. The present beam energy and current are 10 MeV and 30 mA, respectively. The pulse length is 3.3 ms and the repetition rate is 60 Hz, therefore, the duty factor is 20%. In this paper, present designof this compact, midium current, high duty proton linac is presented.

Journal Articles

Evaluation of beam phase restriction with beam phase defining slit in the JAEA AVF cyclotron

Miyawaki, Nobumasa; Fukuda, Mitsuhiro*; Kurashima, Satoshi; Kashiwagi, Hirotsugu; Okumura, Susumu

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.706 - 708, 2015/09

no abstracts in English

46 (Records 1-20 displayed on this page)