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Okazaki, Hiroyuki*; Idesaki, Akira*; Koshikawa, Hiroshi*; Matsumura, Daiju; Ikeda, Takashi*; Yamamoto, Shunya*; Yamaki, Tetsuya*
Journal of Physical Chemistry C, 127(49), p.23628 - 23633, 2023/12
Times Cited Count：0 Percentile：0(Chemistry, Physical)Osawa, Takahito; Kobayashi, Mikihiko*; Konno, Takeshi*; Egashira, Mitsuru*; Okazaki, Ryuji*; Miura, Yayoi*; Nagao, Keisuke*
Measurement, 50, p.229 - 235, 2014/04
Times Cited Count：1 Percentile：16.41(Engineering, Multidisciplinary)A temperature control system for a laser heating has been developed to extract noble gases from minute material samples recovered from the asteroid Itokawa by the Hayabusa spacecraft. An ultra-fine thermocouple was produced from 3% Re-W and 26% Re-W wires 25 
m in diameter, and its electromotive force was calibrated. A temperature control program was originally produced using LabVIEW 2011 in which proportional-integral-derivative (PID) control was not adopted as an algorithm of the program. The program controlled the temperature of the tiny samples appropriately. The average temperature during heating was slightly lower than the setting temperature and the standard deviation and the maximum overshoot were lower than 2.5% and 6.0% of the setting temperature, respectively. The performance of the temperature control system is high enough to conduct the stepwise heating experiment for minute extraterrestrial material samples.
He/
He ratios in natural fluidsBajo, Kenichi*; Sumino, Hirochika*; Toyoda, Michisato*; Okazaki, Ryuji*; Osawa, Takahito; Ishihara, Morio*; Katakuse, Itsuo*; Notsu, Kenji*; Igarashi, Joji*; Nagao, Keisuke*
Mass Spectrometry (Internet), 1(2), p.A0009_1 - A0009_10, 2012/11
The construction of a small-size, magnetic sector, single focusing mass spectrometer (He-MS) for the continuous, on-site monitoring of the He isotope ratio (He/He) is described. The instrument is capable of measuring He/
Ne ratios dissolved in several different types of natural fluids of geochemical interest, such as groundwater and gas from hot springs, volcanoes and gas well fields. Ion optics of the He-MS was designed by using the ion trajectory simulation program TRIO so as to measure He and He simultaneously with a double collector system under mass resolution power of 
500. Presently attained specifications of the He-MS are; (1) mass resolving power of ca. 490, enough to separate He
from interfering ions, HD and H
, (2) ultra-high vacuum condition, and (3) high sensitivity enough to detect He amount 3000000 atoms).
Nagao, Keisuke*; Okazaki, Ryuji*; Nakamura, Tomoki*; Miura, Yayoi*; Osawa, Takahito; Bajo, Kenichi*; Matsuda, Shintaro*; Ebihara, Mitsuru*; Ireland, T.*; Kitajima, Fumio*; et al.
Science, 333(6046), p.1128 - 1131, 2011/08
Times Cited Count：131 Percentile：95.12(Multidisciplinary Sciences)A steroid surface materials record regolith processes and a history of cosmic-ray irradiation. Noble gas isotopes in three rocky grains from Itokawa have been determined. High concentrations of solar He, Ne, and Ar, as high as those in lunar soils, are released at variable temperatures from each sample. The isotopic compositions are essentially identical to those of solar wind but distinguishable in He relative abundance. These noble gas characteristics can be explained by repeated implantation and preferential loss of solar He by removal of weathered He-rich rim on the grain surface through friction among regolith grains on Itokawa. Residence time of regolith materials on Itokawa is alculated to be shorter than 10 Myr, suggesting that regolith materials of small asteroids would escape easily to space.
Kurihara, Ryoichi; Seki, Yasushi; Ueda, Shuzo; Aoki, Isao; Nishio, Satoshi; Ajima, Toshio*; Kunugi, Tomoaki; Takase, Kazuyuki; Yamauchi, Michinori*; *; et al.
Journal of Fusion Energy, 16(3), p.225 - 230, 1997/00
Times Cited Count：3 Percentile：30.34(Nuclear Science & Technology)no abstracts in English
Okazaki, Takashi; Seki, Yasushi; Inabe, Teruo; Aoki, Isao
Fusion Engineering and Design, 30(3), p.201 - 216, 1995/07
Times Cited Count：1 Percentile：17.52(Nuclear Science & Technology)no abstracts in English
Honda, Takuro*; *; *; *; Seki, Yasushi; Aoki, Isao; Kunugi, Tomoaki
Journal of Nuclear Science and Technology, 32(4), p.265 - 274, 1995/04
Times Cited Count：8 Percentile：63.07(Nuclear Science & Technology)no abstracts in English
*; Ogawa, Masuro; Seki, Yasushi; Kunugi, Tomoaki; Aoki, Isao; Honda, Takuro*; *; *
Fusion Engineering and Design, 29, p.238 - 246, 1995/00
Times Cited Count：5 Percentile：49.46(Nuclear Science & Technology)no abstracts in English
*; Seki, Yasushi; Inabe, Teruo; Aoki, Isao
JAERI-M 93-112, 122 Pages, 1993/06
no abstracts in English
*; Nishio, Satoshi; *; Saji, Gen*; Takatsu, Hideyuki; Tada, Eisuke; Aoki, Isao; Seki, Yasushi
Fusion Technology 1992, p.1744 - 1748, 1993/00
no abstracts in English
Seki, Yasushi; *; Aoki, Isao; *; Sato, Satoshi; Takatsu, Hideyuki
Journal of Fusion Energy, 12(1-2), p.11 - 19, 1993/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
Yonomoto, Taisuke; Kukita, Yutaka; Ogawa, Masuro; Kunugi, Tomoaki; Seki, Yasushi; *; Takatsu, Hideyuki
Proc. of the 6th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics,Vol. 2, p.807 - 814, 1993/00
no abstracts in English
*; Nishio, Satoshi; *; Koizumi, Koichi; Shimizu, Katsusuke*; Sasaki, Takashi*; Tada, Eisuke
JAERI-M 92-108, 62 Pages, 1992/07
no abstracts in English
Seki, Yasushi; Takatsu, Hideyuki; Iida, Hiromasa; *; Ogawa, Masuro; Noguchi, Hiroshi; Murata, Mikio; *; *; *; et al.
JAERI-M 91-126, 511 Pages, 1991/08
no abstracts in English
Mizoguchi, Tadanori*; *; Fujisawa, Noboru; Abe, Tetsuya; Hirayama, Toshio; Hitoki, Shigehisa*; *; Koide, Yoshihiko; *; *; et al.
JAERI-M 88-045, 126 Pages, 1988/03
no abstracts in English
*; *; *; Yamamoto, Takumi; Sugihara, Masayoshi; Fujisawa, Noboru
JAERI-M 87-177, 18 Pages, 1987/10
no abstracts in English
*; *; Hitoki, Shigehisa*; Fujisawa, Noboru; Sugihara, Masayoshi; Yamamoto, Shin; Mizoguchi, Tadanori*; Abe, Mitsushi*; *; *; et al.
JAERI-M 87-119, 19 Pages, 1987/08
no abstracts in English
Abe, Mitsushi*; *; *; *; *; *; Shinya, K.*; Sugihara, Masayoshi; Hatayama, Akiyoshi*; Hitoki, Shigehisa*; et al.
JAERI-M 87-116, 13 Pages, 1987/08
no abstracts in English
*; *; Sugihara, Masayoshi; Yamamoto, Shin; Mizoguchi, Tadanori*; Hitoki, Shigehisa*; Abe, Mitsushi*; *; *; *; et al.
JAERI-M 87-110, 11 Pages, 1987/08
no abstracts in English
Hitoki, Shigehisa*; Sugihara, Masayoshi; Yamamoto, Shin; Abe, Mitsushi*; *; *; *; *; Shinya, K.*; Hatayama, Akiyoshi*; et al.
JAERI-M 87-109, 33 Pages, 1987/08
no abstracts in English
