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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.
Sm M
ssbauer and Sm L
-edge X-ray absorption spectroscopiesTsutsui, Satoshi; Higashinaka, Ryuji*; Nakamura, Raito*; Fujiwara, Kosuke*; Nakamura, Jin*; Kobayashi, Yoshio*; Ito, Takashi; Yoda, Yoshitaka*; Kato, Kazuo*; Nitta, Kiyofumi*; et al.
Hyperfine Interactions, 242(1), p.32_1 - 32_10, 2021/12
Times Cited Count：1 Percentile：84.42(Physics, Atomic, Molecular & Chemical)Otani, Masashi*; Futatsukawa, Kenta*; Mibe, Tsutomu*; Naito, Fujio*; Hasegawa, Kazuo; Ito, Takashi; Kitamura, Ryo; Kondo, Yasuhiro; Morishita, Takatoshi; Iinuma, Hiromi*; et al.
Journal of Physics; Conference Series, 1350, p.012097_1 - 012097_7, 2019/12
Times Cited Count：2 Percentile：73.22(Physics, Particles & Fields)A disk and washer (DAW) coupled cavity linac (CCL) has been developed for a middle velocity part in a muon linac to measure muon anomalous magnetic moment and search for electric dipole moment. I will accelerate muons from 
= 
= 0.3 to 0.7 at an operational frequency of 1.3GHz. In this poster, the cavity design, beam dynamics design, and the cold-model measurements will be presented.
Otani, Masashi*; Kawamura, Naritoshi*; Mibe, Tsutomu*; Naito, Fujio*; Yoshida, Mitsuhiro*; Hasegawa, Kazuo; Ito, Takashi; Kondo, Yasuhiro; Hayashizaki, Noriyosu*; Iwashita, Yoshihisa*; et al.
Proceedings of 28th International Linear Accelerator Conference (LINAC 2016) (Internet), p.1037 - 1041, 2017/05
We are developing a linac dedicated to the muon acceleration. It enables us to measure the muon anomalous magnetic moment with an accuracy of 0.1 ppm and search for electric dipole moment with a sensitivity of 10
cm to explore beyond Standard Model of elementary particle physics. As a first step for demonstration of the muon acceleration, we are developing the source of slow muon with which RFQ acceleration is conducted. This paper describes status of these developments.
Kondo, Yasuhiro; Hasegawa, Kazuo; Ito, Takashi; Artikova, S.; Otani, Masashi*; Mibe, Tsutomu*; Naito, Fujio*; Yoshida, Mitsuhiro*; Kitamura, Ryo*; Iwashita, Yoshihisa*; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.66 - 69, 2016/11
We are developing a muon linac for the measurement of the muon anomalous magnetic moment and search for the muon electric dipole moment to explore beyond the Standard Model of elementary particle physics. This muon linac accelerate from room temperature to 212 MeV with normalized transverse emittances of about 1.5 
mm mrad. The muon linac consists of an ultra-slow muon source, a radio frequency quadrupole (RFQ) linac, an inter-digital H-mode drift tube linac (IH-DTL), a disk and washer coupled cavity linac (DAW CCL), and disk loaded structure (DLS) traveling-wave linac. In this paper, the status of the muon linac development, especially, the beam dynamics simulation is descried.
Otani, Masashi*; Naito, Fujio*; Mibe, Tsutomu*; Yoshida, Mitsuhiro*; Hasegawa, Kazuo; Ito, Takashi; Kondo, Yasuhiro; Hayashizaki, Noriyosu*; Iwashita, Yoshihisa*; Iwata, Yoshiyuki*; et al.
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.1543 - 1546, 2016/06
We are developing a linac dedicated to the muon acceleration. It enables us to measure the muon anomalous magnetic moment with an accuracy of 0.1 ppm and search for electric dipole moment with a sensitivity of 10-21e cm to explore beyond Standard Model of elementary particle physics. As a first step for demonstration of the muon acceleration, we are developing the source of slow muon with which RFQ acceleration is conducted. This paper described status of these developments.
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
Kikuzawa, Nobuhiro; Suzuki, Takahiro; Ito, Yuichi; Miura, Akihiko; Fukuta, Shimpei; Ikegami, Masanori*; Sako, Hiroyuki; Kobayashi, Tetsuya; Suzuki, Hiroyuki; Hasegawa, Kazuo
Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.677 - 679, 2010/08
To avoid heat damage and radioactivation by beam loss of the J-PARC accelerator, Machine Protection System (MPS) has been developed. Actually, high responsibility and high reliability have been achieved in J-PARC. Beam-stop method in addition to a way of RFQ OFF has been requested in order to avoid damage to the RFQ. Therefore, we have been developing a fast beam-stop system by using a RF chopper. The fast beam-stop system, including beam test, is described in this paper.
Fang, Z.*; Michizono, Shinichiro*; Anami, Shozo*; Yamaguchi, Seiya*; Naito, Fujio*; Fukui, Yuji*; Kawamura, Masato*; Kubota, Chikashi*; Nammo, Kesao*; Kobayashi, Tetsuya; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.1434 - 1436, 2010/05
The output energy of the J-PARC proton linac will be upgraded from 181 to 400 MeV in the next two years by adding high-b acceleration sections. The upgrade of the FPGA-based digital LLRF controller for the 400 MeV linac will be presented in this paper. This new LLRF controller works for both the 324-MHz low-b and 972-MHz high-b sections. Many functions have been added into the LLRF controller, such as (1) working for different RF systems, (2) gradually increasing the feedback gains in the feedback loop instead of fixed ones, (3) automatic chopped beam compensation, (4) automatically switching the beam loading compensation in accordance with different beam operation mode, (5) input RF-frequency tuning to match the RF cavities during RF start-up, and (6) auto-tuning of the RF cavity tuner by detecting the phase curve of the RF cavity during the field decay instead of the phase difference between the cavity input and output signals.
Yoshida, Zenko; Watanabe, Kazuo; Ito, Mitsuo; Ueno, Takashi; Takeshita, Hidefumi
JAEA-Review 2008-062, 34 Pages, 2009/01
JAEA-Review-2008-062.pdf:4.07MB
Analytical methods for the spent nuclear fuel (SF) have been greatly innovated recently. This methodological innovation is mainly caused by rapid and remarkable progress of induced coupled plasma-mass spectrometry (ICP-MS) which is utilized for the isotopic analysis of actinoid elements (U, Np, Pu, Am, Cm) and fission product elements in the SF samples. The quantity of the objective element as well as the volume of the sample solution needed for the ICP-MS measurement are, in principle, much less than those required for the measurement by other analytical methods. ICP-MS makes it possible to reduce the radiation dose of the operator and to minimize the amount of the radioactive wastes generated from the analytical work. For the precise and accurate isotopic analysis of the objective element in the SF sample by mass spectrometry, the interfering element having isobars needs to be separated prior to the measurement. This review highlights the development of the separation methods and isotopic analysis methods for the analysis of the SF based on more than 50 recent publications and the future problems to be solved and prospects are discussed.
Hasegawa, Kazuo; Asano, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; Ito, Takashi; Kobayashi, Tetsuya; Kondo, Yasuhiro; Namekawa, Yuya; Oguri, Hidetomo; Okoshi, Kiyonori; et al.
Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.55 - 57, 2009/00
The beam commissioning of the J-PARC linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. The linac has delivered beams to the 3 GeV Rapid Cycling Synchrotron for its commissioning, and then, the subsequent Main Ring Synchrotron and the neutron target commissioning. The linac uses a Cs-free LaB
-driven ion source and 20 units of 324 MHz klystrons. As of June 2008, the operation times are about 3,000 and 6,000 hours for the ion source and the RF source, respectively. The operating experience of the linac is described.
Maekawa, Yasunari; Yuasa, Kanako*; Enomoto, Kazuyuki; Matsushita, Harumi*; Kato, Jun*; Yamashita, Takashi*; Ito, Kazuo*; Yoshida, Masaru
Chemistry of Materials, 20(16), p.5320 - 5324, 2008/08
Times Cited Count：2 Percentile：9.29(Chemistry, Physical)Polymer films with acid-responsive chromic dyes and acid generators have been designed for an electron beam (EB)-induced color imaging system. Arylsulfonic acid esters and triphenylsulfonium salts were used as an EB-sensitive acid generator; the acid (H
) allows a chromic reaction with rhodamine B base (RB) and 4,4'-bis(dimethylamino)benzhydrol (BH) to be triggered. Upon EB irradiation, poly(methyl methacrylate) (PMMA) films consisting of RB or BH and acid generators exhibited a characteristic absorption band with 
max at 560 and at 612 nm, respectively, and an isosbestic point. These spectral changes clearly indicate that colorless chromic dyes in PMMA are transformed selectively to the colored form. The color imaging of these films was performed by electron beam direct writing (EBDW) with a 50 nm diameter beam to form 100 - 1000 nm line and space patterns and was evaluated by optical and confocal laser microscopy. EBDW on the acid chromic polymer films, especially for BH, yielded clear color imaging of 100 - 200 nm line and space patterns with a dose of only 10 
C/cm
. The confocal laser microscopy gave thinner lines than the laser wavelength (632.8 nm), probably because of the large change in refractive index of the patterned film induced by EB irradiation even with a low energy dose.
Maekawa, Yasunari; Kato, Jun*; Katakai, Masashi*; Ishihara, Masaaki*; Enomoto, Kazuyuki; Hagiwara, Tokio*; Ishii, Tatsuhito*; Ito, Kazuo*; Koshikawa, Hiroshi; Yoshida, Masaru
Macromolecular Chemistry and Physics, 209(6), p.625 - 633, 2008/03
Times Cited Count：2 Percentile：7.34(Polymer Science)A polysulfonamide and copolymers consisting of sulfonamides and amides underwent Fries rearrangement and scission, forming amino groups upon EB irradiation. The EB irradiation of these films with a dose of 500 C/cm
followed by the color forming reaction provided the color imaging of line/space patterns with resolution of 300 nm.
Morishita, Takatoshi; Ao, Hiroyuki; Asano, Hiroyuki; Ito, Takashi; Ueno, Akira; Okawa, Tomohiro; Hasegawa, Kazuo; Ikegami, Masanori*; Naito, Fujio*; Tanaka, Hirokazu*; et al.
Proceedings of 10th International Workshop on Accelerator Alignment (IWAA 2008) (Internet), 6 Pages, 2008/02
It has been widely accepted that an accurate alignment is essential to achieve high beam quality and highly stable operation increasingly demanded in recent particle accelerators. The J-PARC linac components are finely aligned based on the precise survey network, where we have emphasized on attaining the smoothness between adjacent elements. A floor elevation of the accelerator tunnel has been periodically measured since the completion of the linac building to correct the error by the settlement. The alignment of the linac components have been finished at Sep. 2006 and the beam commissioning has been started at Nov. 2006. After a coarse adjustment of the RF phase and amplitude, nearly complete beam transmission was easily established without using steering magnet. This successful beam transport proves the validity of the alignment strategy and the accurateness of the alignment procedure.
Morishita, Takatoshi; Asano, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Naito, Fujio*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Yoshino, Kazuo*; Ikegami, Masanori*
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1523 - 1525, 2007/06
J-PARC linear accelerator components have been installed. The required alignment accuracy in the J-PARC linac is 0.1mm in transverse direction. In the DTL/SDTL section, the fine alignment was carried out by using an optical alignment telescope along with the cavity installation. The displacement of the DTL by the unit tank connection was monitored by a laser tracker to obtain the tolerable displacement between unit tanks. The heights of cavities and magnets were compensated form the unequal ground movement of the linac tunnel. Finally, all the cavities and magnets are aligned within the tolerable alignment error.
Suzuki, Hiroyuki; Chishiro, Etsuji; Ito, Takashi; Kobayashi, Tetsuya; Hasegawa, Kazuo; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Fang, Z.*; Naito, Fujio*; et al.
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.513 - 515, 2007/00
no abstracts in English
Kato, Jun; Yuasa, Kanako; Matsushita, Harumi*; Maekawa, Yasunari; Enomoto, Kazuyuki; Ishii, Tatsuhito*; Ito, Kazuo*; Yamashita, Takashi*
Journal of Photopolymer Science and Technology, 19(1), p.105 - 110, 2006/00
Times Cited Count：2 Percentile：6.5(Polymer Science)The novel electron beam (EB)-induced color imaging system, consisting of polymer films with acid-responsive chromic molecules (chromic dyes) and EB-acid generators (EBAGs) was proposed. EB irradiation of the acid-chromic polymer films induced acid generation from EBAG, resulting in color formation of the acid-chromic molecules (protonated forms). Nanoscale color imaging on the acid- chromic polymer films was carried out using EB scanning direct drawing. Clear color imaging of 200 nm square and 100 nm line/space patterns could be observed with a dose of only 50 C cm. Furthermore, the large EB-induced refractive index change of these films (0.013 at 632.8 nm) was observed in both TE and TM modes by an m-line method, which is sufficient to create an optical circuit.
Suzuki, Hiroyuki; Chishiro, Etsuji; Ito, Takashi; Hasegawa, Kazuo; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Fang, Z.*; Naito, Fujio*; Tanaka, Hirokazu*
Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.493 - 495, 2006/00
no abstracts in English
Morishita, Takatoshi; Ao, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*; Kubota, Chikashi*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Naito, Fujio*; et al.
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.266 - 268, 2005/07
J-PARC linear accelerator components are now being installed in the accelerator tunnel. Markings are placed on the floor, which act as a reference for the initial alignment at the installation. A planned and ongoing alignment schemes for the installation of linac components and watching the long term motion of the building are described.
Morishita, Takatoshi; Ao, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*; Kubota, Chikashi*; Naito, Fujio*; Takasaki, Eiichi*; Tanaka, Hirokazu*; et al.
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2851 - 2853, 2005/00
In J-PARC linac, a precise alignment of accelerator components is essential for high quality beam acceleration. Markings have been placed on the floor, which act as a reference for the initial alignment at the installation. For a straight line alignment, the wire position sensor is placed on the offset position with respect to the beam center by a target holder. The hydrostatic levering system is used for watching the floor elevation over the long period.
