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Journal Articles

Upgrade of the 3-MeV linac for testing of accelerator components at J-PARC

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:0 Percentile:0.07

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.

Journal Articles

Development of a beam window protection system for the J-PARC Linac

Takahashi, Hiroki; Hatakeyama, Shuichiro; Sawabe, Yuki; Miyao, Tomoaki*; Ishiyama, Tatsuya*; Suzuki, Takahiro*

Journal of Physics; Conference Series, 1350, p.012142_1 - 012142_5, 2019/12

 Times Cited Count:0 Percentile:0.07

At the J-PARC Linac, beam conditioning and study are performed using beam dumps (BDs). To be a partition with the high vacuum section, a beam window (material Ni, 0.38 mm thick, mirror-shape) is installed upstream of the BD along the beam line. Beams that can be accepted by the beam window are about 1/50 or less of rated beam according to thermal evaluation and experience. Therefore, when using a beam dump, it is necessary not to exceed this tolerance. In a 2018 beam study, the beam e that exceeded tolerance was incident on the 0-degree dump due to human error, and the beam window was cracked. Then, this has revealed the need for protection of the beam window by hardware. Therefore, based on the existing system for monitoring the per-hour beam amount, we began to develop a system to monitor one shot beam and one second beam amount. And, we succeeded in implementing a system that protects the beam window by monitoring the beam in a short time (one shot, and for one second). In addition, the performance tests using actual beams were performed, and it was confirmed that the developed system had sufficient performance requirements to protect the beam window.

Journal Articles

Update of MPS modules for J-PARC Linac and RCS

Takahashi, Hiroki; Hayashi, Naoki; Nishiyama, Koichi*; Suzuki, Takahiro*; Ishiyama, Tatsuya*

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.271 - 274, 2019/07

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 of the J-PARC. Then, the system has been working stably for more than ten years. On the other hand, since there are many MPS modules that have been used from the beginning of J-PARC operation, it is important to systematically proceed with updating (replacement) of modules as a measure against aging of MPS. However, the main components of the existing MPS module have been discontinued. Therefore, it is indispensable to redesign the MPS modules in consideration of improvement such as the compatibility with existing modules and the miniaturization. In this paper, the development status of the new module and the update plan of MPS for Linac and RCS are detailed.

Journal Articles

Development of a beam window protection system for the J-PARC Linac

Takahashi, Hiroki; Hatakeyama, Shuichiro; Sawabe, Yuki; Miyao, Tomoaki*; Ishiyama, Tatsuya*; Suzuki, Takahiro*

Proceedings of 10th International Particle Accelerator Conference (IPAC '19) (Internet), p.3886 - 3889, 2019/06

At the J-PARC Linac, beam conditioning and study are performed using beam dumps (BDs). To be a partition with the high vacuum section, a beam window (material Ni, 0.38 mm thick, mirror-shape) is installed upstream of the BD along the beam line. Beams that can be accepted by the beam window are about 1/50 or less of rated beam according to thermal evaluation and experience. Therefore, when using a beam dump, it is necessary not to exceed this tolerance. In a 2018 beam study, the beam e that exceeded tolerance was incident on the 0-degree dump due to human error, and the beam window was cracked. Then, this has revealed the need for protection of the beam window by hardware. Therefore, based on the existing system for monitoring the per-hour beam amount, we began to develop a system to monitor one shot beam and one second beam amount. And, we succeeded in implementing a system that protects the beam window by monitoring the beam in a short time (one shot, and for one second). In addition, the performance tests using actual beams were performed, and it was confirmed that the developed system had sufficient performance requirements to protect the beam window.

Journal Articles

Negative hydrogen ion beam irradiation experiments of beam scrapers using the J-PARC 3 MeV-Linac

Hirano, Koichiro; Ishiyama, Tatsuya; Kurihara, Toshikazu*; Sugimura, Takashi*; Maruta, Tomofumi*

Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.847 - 852, 2017/12

Beam scrapers made of carbon composite have been used in the MEBT1 between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC Linac. We have conducted the scraper irradiation test with the 3 MeV linac. The test piece of the scraper was irradiated by the H$$^{-}$$ beam up to particle number of 1.2E20. We measured the surface temperature of more than 3000$$^{circ}$$C using a high-speed radiation thermometer and observed the irradiation damage on the scraper by using the laser microscope. When the surface temperature exceeded 2900$$^{circ}$$C, the ionic current of carbon and the irradiation damage on the surface of the test piece rapidly increased. This paper describes beam irradiation test results of the scraper.

Journal Articles

A 3 MeV linac for development of accelerator components at J-PARC

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.

Journal Articles

Development of a control system at a 3 MeV linac in J-PARC

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.

Journal Articles

Development of beam scrapers using a 3-Mev linac at J-PARC

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$$^{circ}$$ 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.

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

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

no abstracts in English

Journal Articles

Construction of control system for J-PARC RF ion source & RFQ III test stand

Fukuta, Shimpei; Sawabe, Yuki; Suzuki, Takahiro*; Ishiyama, Tatsuya*; Kawase, Masato*; Ito, Yuichi; Kato, Yuko; Yoshii, Akinobu; Kikuzawa, Nobuhiro; Ouchi, Nobuo

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1122 - 1125, 2014/06

The installation of Cs-seeded RF-driven H$$^{-}$$ ion source (RF ion source) to J-PARC LINAC is scheduled in 2014. Similarly the replacement of RFQ III from RFQ is scheduled in 2014. The test stand of the cooperation of RF ion source & RFQ III is being made in the J-PARC LINAC building for the beam acceleration examination now. The J-PARC control group designed test stand control system by thinking that test stand control system had to be equal to J-PARC accelerator control system. Specifically, Introduction of MPS for protect an apparatus. Implementation of EPICS environment for remotely controlling the equipment. It is construction of the timing system for sending a timing signal to each accelerator component device. This report describes construction of the control system in a test stand.

Journal Articles

Development of MLF-inhibit system for J-PARC

Ishiyama, Tatsuya; Ito, Yuichi; Kikuzawa, Nobuhiro; Suzuki, Takahiro; Oi, Motoki; Meigo, Shinichiro; Sakai, Kenji; Kato, Yuko

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.714 - 716, 2013/08

no abstracts in English

Journal Articles

HBC foil beam study and long-term observation at the 3-GeV RCS in J-PARC

Yoshimoto, Masahiro; Saha, P. K.; Yamazaki, Yoshio; Kawase, Masato; Saeki, Riuji; Hayashi, Naoki; Yamamoto, Kazami; Hotchi, Hideaki; Ishiyama, Tatsuya; Kinsho, Michikazu; et al.

Journal of Physics; Conference Series, 417, p.012073_1 - 012073_6, 2013/03

 Times Cited Count:4 Percentile:79.92

The HBC foil are installed in the J-PARC RCS for the charge-exchange H$$^{-}$$ beam injection. In order to examine the characteristics of the HBC foils, beam studies for the HBC foil were carried out from the viewpoint of foil's life time and the beam survival rate due to foils. According to the compromise between charge-exchange efficiency and foil scattering beam loss, we optimized the foils thickness for user operation. The long-term observation during the user operation as well as the HBC foil endurance test for its life time evaluation was carried out. Even after one year was operation, there was no deterioration of the stripping foil.

Journal Articles

Development of J-PARC LINAC/RCS MPS Sub System, 2

Suzuki, Takahiro; Ito, Yuichi; Ishiyama, Tatsuya; Maruta, Tomofumi; Kato, Yuko; Kawase, Masato; Fukuta, Shimpei; Sawabe, Yuki*; Kikuzawa, Nobuhiro

Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.527 - 529, 2011/08

no abstracts in English

Journal Articles

Development of control system for J-PARC LINAC ACS section

Sawabe, Yuki*; Suzuki, Takahiro; Ishiyama, Tatsuya; Fukuta, Shimpei; Kikuzawa, Nobuhiro

Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.680 - 682, 2010/08

The output energy of the J-PARC proton LINAC will be upgraded from 181 to 400 MeV in the next two years by adding ACS modules. The present status of upgrade of the control system for the ACS section will be presented in this paper.

Journal Articles

Beam study results with HBC stripping foils at the 3-GeV RCS in J-PARC

Yoshimoto, Masahiro; Yamazaki, Yoshio; Hayashi, Naoki; Yamamoto, Kazami; Saeki, Riuji; Hotchi, Hideaki; Saha, P. K.; Harada, Hiroyuki; Kawase, Masato; Ishiyama, Tatsuya; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.3927 - 3929, 2010/05

The ($underline{H}$)ybrid type thick ($underline{B}$)oron-doped ($underline{C}$)arbon (HBC) stripping foils are installed and used for the beam injection at the 3GeV RCS (Rapid Cycling Synchrotron) in J-PARC (Japan Proton Accelerator Research Complex). Up to now, the performance deterioration of the stripping foils can not be seen after the long beam irradiation for the 120kW user operation and 300kW high power beam demonstration at the RCS. In order to examine the characteristic of the HBC foils, various beam studies were carried out. The beam-irradiated spot at the foil was measured by scanning the foil setting position, the charge exchange efficiency was evaluated with various thickness foils, and the effect of the SiC fibers supporting the foil mounting was checked with different mounting foils. Beam study results obtained with using the HBC foils will be presented. In addition, the trends of outgas from the stripping foils and the deformations of the foils during the beam irradiation will be reported.

Journal Articles

Subsurface geometry and structural evolution of the eastern margin fault zone of the Yokote basin based on seismic reflection data, northeast Japan

Kagohara, Kyoko; Ishiyama, Tatsuya*; Imaizumi, Toshifumi*; Miyauchi, Takahiro*; Sato, Hiroshi*; Matsuta, Nobuhisa*; Miwa, Atsushi*; Ikawa, Takeshi*

Tectonophysics, 470(3-4), p.319 - 328, 2009/05

 Times Cited Count:4 Percentile:14.45(Geochemistry & Geophysics)

Seismic reflection profiles across coseismic fault scarps of the A.D. 1896 Rikuu earthquake along the eastern margin of the Yokote basin fault zone (EYBFZ), correlated with borehole stratigraphy and geologic mapping, provide insights into its detailed structural evolution. In spite of along-strike variations of thrust geometries both at ground surface and at shallow depth, the EYBFZ has commonly formed as forward breaking imbricate thrust systems. Spatial variations in the long-term uplift rates estimated from cross-section balancing are consistent with mountain topography, in contrast to their weak coupling with the magnitudes of short-term uplift rates and coseismic uplift during the A.D. 1896 earthquake. This suggests that mechanical decoupling of Miocene mudstone that formed frontal emergent thrust faults may have enhanced the slip at shallowest structural levels at shorter timescales.

Journal Articles

Performance of a 4$$pi$$ Ge spectrometer for neutron capture cross section measurements

Oshima, Masumi; Hori, Junichi*; Harada, Hideo; Furutaka, Kazuyoshi; Koizumi, Mitsuo; Kitatani, Fumito; Toh, Yosuke; Kimura, Atsushi; Nakamura, Shoji; Igashira, Masayuki; et al.

Proceedings of International Conference on Nuclear Data for Science and Technology (ND 2007), Vol.1, p.603 - 606, 2008/05

Neutron capture cross sections of minor actinides and long-lived fission products are important for the R&D of innovative nuclear reactors. However, those data are rather poor both in quality and in quantity at present. Thus, we have started projects for neutron cross section measurements. We will construct an innovative $$gamma$$-ray spectrometer consisting of Ge crystals and BGO shields. The neutron cross section measurements will be done at KUR linac and JAEA JRR-3M facilities, which will be extended at the high-intensity neutron source at J-PARC.

Journal Articles

Development of J-PARC linac/RCS MPS sub system

Suzuki, Takahiro; Yoshikawa, Hiroshi; Sakaki, Hironao; Takahashi, Hiroki; Ito, Yuichi; Kato, Yuko; Kawase, Masato; Ishiyama, Tatsuya; Fukuta, Shimpei*; Watanabe, Kazuhiko*

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.84 - 86, 2008/00

no abstracts in English

Journal Articles

Current status of the control system for J-PARC accelerator complex

Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.

Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10

J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.

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