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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.
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
Nakamura, Kazuo*; Jiang, Y.*; Liu, X.*; Mitarai, Osamu*; Kurihara, Kenichi; Kawamata, Yoichi; Sueoka, Michiharu; Hasegawa, Makoto*; Tokunaga, Kazutoshi*; Zushi, Hideki*; et al.
Fusion Engineering and Design, 86(6-8), p.1080 - 1084, 2011/10
Times Cited Count：4 Percentile：32.59(Nuclear Science & Technology)Sato, Susumu; Miura, Akihiko; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Sako, Hiroyuki; Morishita, Takatoshi; Yoshikawa, Hiroshi; Hasegawa, Kazuo; Kobayashi, Tetsuya
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.298 - 300, 2010/03
no abstracts in English
Sato, Susumu; Miura, Akihiko; Tomisawa, Tetsuo; Sako, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yoshikawa, Hiroshi; Igarashi, Zenei*; Ikegami, Masanori*
Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.3591 - 3593, 2009/05
Hayashi, Kimio; Nakagawa, Tetsuya; Onose, Shoji; Ishida, Takuya; Nakamichi, Masaru; Katsuyama, Kozo; Iwamatsu, Shigemi; Hasegawa, Teiji; Kodaka, Hideo; Takatsu, Hideyuki; et al.
JAEA-Technology 2009-007, 168 Pages, 2009/03
JAEA-Technology-2009-007.pdf:31.88MB
In-pile functional tests of breeding blankets have been planned by Japan Atomic Energy Agency (JAEA), using a test blanket module (TBM) which will be loaded in the International Thermonuclear Experimental Reactor (ITER). In preparation for the in-pile functional tests, JAEA has been being performed irradiation experiments of lithium titanate (Li
TiO
), which is the first candidate of solid breeder materials for the blanket of the demonstration reactor (DEMO) under designing in Japan. The present report describes (1) results of a detailed design and trial fabrication tests of a dismantling apparatus for irradiation capsules which were used in irradiation experiments by the Japan Materials Testing Reactor (JMTR) of JAEA, and (2) results of a preliminary investigation of a glove box facility for post-irradiation examinations (PIEs). In the detailed design of the dismantling apparatus, datailed specifications and the installation methods were examined, based on results of a conceptual design and basic design. In the trial fabrication, cutting tests were curried out by making a mockup of a cutting component. Furthermore, a preliminary investigation of a glove box facility was carried out in order to secure a facility for PIE work after the capsule dismantling, which revealed a technical feasibility.
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.
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.
Ao, Hiroyuki; Hirano, Koichiro; Morishita, Takatoshi; Asano, Hiroyuki; Naito, Fujio*; Ueno, Akira; Ikegami, Masanori*; Hasegawa, Kazuo; Yamazaki, Yoshishige; Paramonov, V.*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.494 - 496, 2008/00
The J-PARC ACS cavity consists of many cell parts. For the mass production, the ACS requires about 1300 cell parts, so that it is important to reduce the machining time. In the previous ACS model, it took about three hours per one coupling slot. We, therefore, optimized the slot design, the tolerance, and the machining process. As a result, the machining time reduced to forty-five minutes per one slot. The four test cells were fabricated to measure the frequencies and Q-values, and these results were compared with the electromagnetic analysis with the Microwave Studio. Between the analysis and the measurement, the differences are 1
1.5 MHz and 45 MHz, respectively, for the accelerating mode, and for the coupling mode.
Okawa, Tomohiro; Ao, Hiroyuki; Sako, Hiroyuki; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.3324 - 3326, 2007/08
In the beam commissioning of J-PARC linac, we use three simulations codes for accelerator modeling, which includes TRACE3D, XAL online model and PARMILA. TRACE3D is mainly used to determine the initial configuration for quadrupole magnets, XAL online model is mainly used for the transverse matching and orbit correction and PARMILA is mainly used to model phase-slip effects in a phase-scan tuning. We have compared the modeling with the experimental results obtained in the beam commissioning to date, where a basic agreement has been confirmed between the modeling and the actual beam behavior.
Morishita, Takatoshi; Asano, Hiroyuki; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1520 - 1522, 2007/06
J-PARC linear accelerator components have been installed. Precise alignment of the accelerator components is essential for high quality beam acceleration. Before the beam commissioning, a precise survey for alignment has been performed. The reference points on the tunnel wall were set up to built a survey network. Based on the survey results, the magnets in the straight section were re-aligned finely. Then, the results of the displacement are confirmed to be tolerable for the beam commissioning.
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.
Ikegami, Masanori*; Lee, S.*; Akikawa, Hisashi*; Igarashi, Zenei*; Kondo, Yasuhiro; Okawa, Tomohiro; Ueno, Akira; Sako, Hiroyuki; Ao, Hiroyuki; Sato, Susumu; et al.
KEK Proceedings 2006-15 (CD-ROM), p.347 - 349, 2007/03
We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.
Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.749 - 757, 2007/00
no abstracts in English
-type tetragonal crystal structureMaehira, Takahiro*; Hotta, Takashi; Ueda, Kazuo*; Hasegawa, Akira*
New Journal of Physics (Internet), 8(2), p.24_1 - 24_20, 2006/02
Times Cited Count：16 Percentile：64.65(Physics, Multidisciplinary)By using a relativistic band-structrue calculation method, we investigate energy band structures and the Fermi surfaces of NpTGa, PuTGa, and AmCoGa with transition metal atoms T. It is found in common that the energy bands in the vicinity of the Fermi level are mainly due to the large hybridization between 
and Ga 
electrons. For PuTGa, we observe several cylindrical sheets of Fermi surfaces with large volume for T=Co, Rh, and Ir. It is also found that the Fermi surfaces of NpFeGa, NpCoGa, and NpNiGa are similar to those of UCoGa, UNiGa, and PuCoGa, respectively, except for small details. For AmCoGa, the Fermi surfaces are found to consist of large cylindrical electron sheets and small closed hole sheets, similar to PuCoGa. The similarity is basically understood by a rigid-band picture.
Kondo, Yasuhiro; Ueno, Akira; Hasegawa, Kazuo
Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.388 - 390, 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.
Ao, Hiroyuki; Ueno, Akira; Morishita, Takatoshi; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.332 - 334, 2005/07
The first ACS module consists of two 5-cells ACS tanks and a 5-cells bridge cavity for the buncher module. Three RF tuners are installed to the bridge cavity for fine RF tuning. An operating frequency should be tuned to 972 MHz within the fine-tuning range before a brazing process in a factory. The tuning procedure has been studied with RF simulation analysis and cold-model measurements for ACS and bridge cells. This paper describes RF tuning results, fabrication status and related development items.
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.
Ao, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Paramonov, V.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2684 - 2686, 2005/00
J-PARC Linac starts with 180-MeV SDTL temporary, and it is upgraded to 400-MeV with 21 ACS (Annular Coupled Structure) modules and two ACS bunchers and two debunchers. First buncher module is under fabrication, and second buncher and a few accelerating modules are also planed until FY2006. The first ACS module consists of two 5-cell ACS tanks and a 5-cell bridge cavity for the buncher module. Three RF tuners are installed to the bridge cavity for fine RF tuning. An operating frequency should be tuned to 972 MHz within the fine-tuning range before a brazing process in a factory. The tuning procedure has been studied with RF simulation analysis and cold-model measurements for ACS and bridge cells. This paper describes RF tuning results, fabrication status and related development items.
