Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tsuboi, Masatoshi; Takase, Yuki; Otsu, Shuya; Goto, Sho; Uno, Shota; Sakamoto, Gen; Mitoma, Kenshin; Yasuo, Kiyoshi
Nihon Hozen Gakkai Dai-21-Kai Gakujutsu Koenkai Yoshishu, 4 Pages, 2025/07
no abstracts in English
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：60 Percentile：95.10(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.
Ha, Yoosung; Shimodaira, Masaki; Tobita, Toru; Hanawa, Satoshi; Yamasaki, Shota*; Uno, Sadanori*
2018-Nendo Ryoshi Kagaku Gijutsu Kenkyu Kaihatsu Kiko Shisetu Kyoyo Jisshi Hokokusho (Internet), 3 Pages, 2019/09
no abstracts in English
-ray irradiation facilitiesAgematsu, Takashi; Uno, Sadanori; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Yamasaki, Shota; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 173, 2016/02
The electron accelerator and the three -ray irradiation facilities of Takasaki Advanced Radiation Research Institute were operated for various research subjects according to the operation plan in FY 2014. The number of research subjects in FY 2014 decreased at the electron accelerator with operation stop by accelerator trouble, and increased slightly at the -ray irradiation facilities as compared with FY 2013, and research subjects were 205 and 857, respectively. Among these research subjects, 35 and 172 related to recovery from the Fukushima Daiichi Nuclear disaster, respectively, were performed at the electron accelerator and the -ray irradiation facilities, respectively.
Co -ray irradiation facilitiesUno, Sadanori; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Yamasaki, Shota; Agematsu, Takashi; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 172, 2016/02
This paper reports on the operation status of the -ray irradiation facilities and the electron accelerator in fiscal 2014 at the Takasaki Advanced Radiation Research Institute of JAEA. The -ray irradiation facilities were operated smoothly, whereas the electron accelerator stopped for five months because of successive troubles of discharge due to deterioration of equipment over thirty-four years. The annual operation times of the -ray irradiation facilities of the first, second and food buildings were 19,907, 13,831 and 7,293 hours, respectively, and that of the electron accelerator was 746 hours. The -ray irradiation facilities were replenished with new five sources of 2.22 PBq, and twenty old sources were removed for disposal. The electron accelerator was repaired for each trouble, however, the complete recovery has not yet been achieved.
Uno, Sadanori; Hanaya, Hiroaki; Yamasaki, Shota; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Agematsu, Takashi; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
Dai-28-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.121 - 123, 2015/12
no abstracts in English
-ray irradiation facilitiesAgematsu, Takashi; Uno, Sadanori; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Yamasaki, Shota; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
no journal, ,
The -ray irradiation facility have been operated smoothly in FY2014, on the other hand, the rate of operation was down to 60% compared to FY2013 for troubles at the electron accelerator. The annual operation time in FY 2014 for the electron accelerator, the first, the second cobalt irradiation facility and food irradiation facility are 746h, 19,907h, 13,831h and 7,293h, respectively. Typical maintenance is as follows. The isolation pillar of high-voltage circuit, leakage of isolation gas were repaired, SF
isolation gas was purified at the electron accelerator. The periodic maintenance was done for the second irradiation facility. New pieces of Co sources were purchased and loaded to the food irradiation facility.
Takeuchi, Kenji; Domura, Kazuyuki; Suzuki, Hisanori; Sasaki, Shunichi; Komori, Tsuyoshi; Uno, Shota
no journal, ,
no abstracts in English
