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Nemoto, Takahiro; Arakawa, Ryoki; Kawakami, Satoru; Nagasumi, Satoru; Yokoyama, Keisuke; Watanabe, Masashi; Onishi, Takashi; Kawamoto, Taiki; Furusawa, Takayuki; Inoi, Hiroyuki; et al.
JAEA-Technology 2023-005, 33 Pages, 2023/05
JAEA-Technology-2023-005.pdf:5.25MB
During shut down of the HTTR (High Temperature engineering Test Reactor) RS-14 cycle, an increasing trend of filter differential pressure for the helium gas circulator was observed. In order to investigate this phenomenon, the blower of the primary helium purification system was disassembled and inspected. As a result, it is clear that the silicon oil mist entered into the primary coolant due to the deterioration of the charcoal filter performance. The replacement and further investigation of the filter are planning to prevent the reoccurrence of the same phenomenon in the future.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：44 Percentile：97.1(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Arakawa, Kazuo; Oikawa, Masakazu*; Shimada, Hirofumi*; Kamiya, Tomihiro; Nakano, Takashi*; Yusa, Ken*; Kato, Hiroyuki*; Sato, Takahiro; Agematsu, Takashi; Kashiwagi, Hirotsugu; et al.
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.279 - 281, 2007/00
no abstracts in English
CMiyahara, Shinya; Sagawa, Norihiko; Sone, Toru; Hara, Hiroshi; Arakawa, Toru*
Journal of Nuclear Science and Technology, 29(4), p.351 - 357, 1992/04
None
Matsue, Masaki*; Arakawa, Satoru*; Tanaka, Toshihiro*; Sawa, Soji*; Ogiwara, Norio; Suganuma, Kazuaki
no journal, ,
At the 3 GeV-RCS in J-PARC project, pure Ti is adopted as a material for bellows. The space available for the bellows is so narrow that the requirements are hard. To make the hydro-formed bellows like the welded ones, it is essential to bend and press the Ti plates and to keep the 2 sides facing each other in close contact. The repetition of the combination of bending (pressing) with annealing enables us to realize the close contact of Ti plates. We produced the experimental bellows with the inner diameter of 50 mm. It shows suitable performance: (1) spring rates are 1.5 N/mm (axial) and 4.0 N/mm (lateral), respectively; (2) endurance test shows the fatigue life of over than 1 million cycles with the displacement of 20 mm. Thus we have succeeded in developing the hydro-formed bellows with the same flexibility as the welded ones. Now we have completed the performance tests about the prototype of the large bellows (400 mm in a diameter), and mass production has been performed.
Sakurai, Eiko*; Ishii, Keizo*; Yamanaka, Kentaro*; Okura, Satoru*; Fujiki, Kota*; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Kamiya, Tomihiro; Sato, Takahiro; Arakawa, Kazuo*; et al.
no journal, ,
Cognitive degradation and behavior disorder occur under the mental disease caused by stimulant drugs. In this study, it was continuously administered to mice. After that, neuropoiesis of dentate gyrus and trace elements in its brain were analyzed by in-air micro-PIXE. As a result, the distribution of trace elements was different from that of normal mice.
