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Kawamura, Hideyuki; Kobayashi, Takuya; Nishikawa, Shiro*; Ishikawa, Yoichi*; Usui, Norihisa*; Kamachi, Masafumi*; Aso, Noriko*; Tanaka, Yusuke*; Awaji, Toshiyuki*
Global Environmental Research (Internet), 18(1), p.81 - 96, 2014/09
A drift simulation of tsunami debris flushed out from the Tohoku district, Japan, into the North Pacific due to the tsunami on March 11, 2011, has been conducted to monitor and forecast the drift path over the North Pacific. Results showed that tsunami debris was first transported eastward by the intense Kuroshio Extension and westerly, spreading in the north and south directions by both an energetic ocean eddy and a storm track over the ocean. Tsunami debris with larger windage was transported over the North Pacific by ocean surface wind rather than ocean current and arrived at the west coast of the North American Continent in the fall of 2011. Tsunami debris located near the North American Continent migrated, associated with the basin-scale seasonal change in the atmospheric pressure pattern. Our forecast run suggested that the tsunami debris belt will be formed from the North American Continent in the east to the Philippines in the west.
Ogiwara, Norio; Yanagibashi, Toru; Hikichi, Yusuke; Nishikawa, Masaaki; Kamiya, Junichiro; Wada, Kaoru*
Vacuum, 98, p.18 - 21, 2013/12
Times Cited Count：7 Percentile：30.71(Materials Science, Multidisciplinary)Kamiya, Junichiro; Ogiwara, Norio; Nishikawa, Masaaki; Hikichi, Yusuke; Yanagibashi, Toru; Kinsho, Michikazu
Vacuum, 98, p.12 - 17, 2013/12
Times Cited Count：9 Percentile：37.98(Materials Science, Multidisciplinary)One of the reasons of a beam loss in a high power accelerator is leakage magnetic field from a magnet at a close beam line, which distorts the beam orbit and makes the beam hit the wall of the beam pipe. The most effective way to shield such leakage field is to cover the beam by the magnetic materials at the nearest space. This means that vacuum chambers should be made of the magnetic materials. We selected the permalloy, which has very high magnetic permeability for such a magnetic material. However, there is not proven evidence of the vacuum chambers, which are made of magnetic materials. We have developed a vacuum chamber of such new material with the object of vacuum and magnetic characteristics.
Ogiwara, Norio; Suganuma, Kazuaki; Hikichi, Yusuke; Nishikawa, Masaaki; Yanagibashi, Toru; Kamiya, Junichiro; Kinsho, Michikazu
Journal of the Vacuum Society of Japan, 56(5), p.159 - 162, 2013/05
Tanabe, Yusuke*; Iwamoto, Takashi*; Takahashi, Junichi*; Nishikawa, Hiroyuki*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 129, 2013/01
Kamiya, Junichiro; Ogiwara, Norio; Nishikawa, Masaaki; Hikichi, Yusuke; Yanagibashi, Toru; Kinsho, Michikazu
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.2522 - 2524, 2012/05
In the vacuum system of J-PARC Rapid cycling synchrotron (RCS), we use beam pipes and bellows whose materials are vacuum fired at 700
850 
C in order to eliminate atoms in their bulk who are origin of outgassing. Until now, beam power has been increased up to 300 kW. Pressure in synchrotron beam line increased when the high power beam was accelerated. However, increment of pressure has reduced during the continuous beam operation. It is because the molecules, which adsorb on surface of the wall of the vacuum chambers, desorb by an ion bombardment and a heat generation due to an eddy current. Because the atoms in the bulk is eliminated, desorption of the molecules, which adsorb on the surface, means the reduction of the outgassing from the wall. In this presentation, we will report the past situation of the vacuum system during the beam operation. In addition, we also show the status after the Great East Japan Earthquake.
Ogiwara, Norio; Suganuma, Kazuaki; Hikichi, Yusuke; Nishikawa, Masaaki; Yanagibashi, Toru; Kamiya, Junichiro; Kinsho, Michikazu
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.487 - 489, 2012/05
Kamiya, Junichiro; Ogiwara, Norio; Nishikawa, Masaaki; Hikichi, Yusuke; Yanagibashi, Toru; Suganuma, Kazuaki
Journal of the Vacuum Society of Japan, 55(4), p.156 - 159, 2012/04
It is usually difficult to reduce outgassing of a large structure inside a vacuum chamber by baking the whole chamber, which causes the large extension of the chamber and needs a lot of heater power. The solution is to rise the temperature of structure object without heating the vacuum chamber. This means to install heat source inside the chamber and increase the heat quantity to the object by inserting the heat shield between the object and the chamber. In the particle accelerator field, there are a lot of such requirements for reducing outgassing of structures inside vacuum chambers. One example is a kicker magnet, which is installed in a vacuum chamber and consists mainly of ferrite cores and aluminum electric plates. We applied the above method to the outgassing reduction of the kicker. In this article, we show outline of this in-situ bake-out method, the effects of the heat shield on the heat quantity and the result of the outgassing reduction.
Tanabe, Yusuke*; Nishikawa, Hiroyuki*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 163, 2012/01
m band using focused proton beamMiura, Kenta*; Machida, Yuki*; Uehara, Masato*; Kiryu, Hiromu*; Ozawa, Yusuke*; Sasaki, Tomoyuki*; Hanaizumi, Osamu*; Sato, Takahiro; Ishii, Yasuyuki; Koka, Masashi; et al.
Key Engineering Materials, 497, p.147 - 150, 2012/00
Times Cited Count：7 Percentile：95.12(Engineering, Electrical & Electronic)m band using focused proton beamMiura, Kenta*; Machida, Yuki*; Uehara, Masato*; Kiryu, Hiromu*; Ozawa, Yusuke*; Sasaki, Tomoyuki*; Hanaizumi, Osamu*; Sato, Takahiro; Ishii, Yasuyuki; Koka, Masashi; et al.
Key Engineering Materials, 497, p.147 - 150, 2011/12
Times Cited Count：6 Percentile：2.48Tanabe, Yusuke*; Nishikawa, Hiroyuki*; Seki, Yoshihiro*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Watanabe, Toru*; Sekiguchi, Atsushi*
Microelectronic Engineering, 88(8), p.2145 - 2148, 2011/08
Times Cited Count：9 Percentile：47.34(Engineering, Electrical & Electronic)Shiine, Yasuharu*; Nishikawa, Hiroyuki*; Furuta, Yusuke*; Kanamitsu, Kaoru*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*
Microelectronic Engineering, 87(5-8), p.835 - 838, 2010/05
Times Cited Count：7 Percentile：42.49(Engineering, Electrical & Electronic)Kamiya, Tomihiro; Takano, Katsuyoshi; Ishii, Yasuyuki; Sato, Takahiro; Oikawa, Masakazu*; Okubo, Takeru; Haga, Junji*; Nishikawa, Hiroyuki*; Furuta, Yusuke*; Uchiya, Naoyuki*; et al.
Nuclear Instruments and Methods in Physics Research B, 267(12-13), p.2317 - 2320, 2009/06
Times Cited Count：7 Percentile：47.15(Instruments & Instrumentation)Kamiya, Tomihiro; Nishikawa, Hiroyuki*; Sato, Takahiro; Haga, Junji; Oikawa, Masakazu*; Ishii, Yasuyuki; Okubo, Takeru; Uchiya, Naoyuki; Furuta, Yusuke*
Applied Radiation and Isotopes, 67(3), p.488 - 491, 2009/03
Times Cited Count：4 Percentile：30.49(Chemistry, Inorganic & Nuclear)Development of a mask-less ion beam lithography technique for fabricating micro- or nano-meter sized structures has been started at the microbeam systems in the ion accelerator facility of JAEA Takasaki (TIARA) in collaboration with Shibaura Institute of Technology. In order to obtain a high precision measure for microbeam size estimation and lens system optimization, or for improvement of spatial resolution down to 100 nm level, we applied this lithography technique itself combined with the electroplating process to make a Ni relief pattern as an optimum resolution standard to be used in secondary electron imaging. In this work, using this standard, the smallest beam size could be obtained. This paper also discuses on the scattering of ions in the materials influenced to the resolution using a Monte Carlo simulation code.
Uchiya, Naoyuki*; Furuta, Yusuke*; Nishikawa, Hiroyuki*; Watanabe, Toru*; Haga, Junji; Sato, Takahiro; Oikawa, Masakazu; Ishii, Yasuyuki; Kamiya, Tomihiro
Microsystem Technologies, 14(9-11), p.1537 - 1540, 2008/10
Times Cited Count：17 Percentile：64.34(Engineering, Electrical & Electronic)Katayama, Kazunari*; Takeishi, Toshiharu*; Nagase, Hiroyasu*; Manabe, Yusuke*; Nishikawa, Masabumi*; Miya, Naoyuki; Masaki, Kei
Fusion Science and Technology, 48(1), p.561 - 564, 2005/07
Times Cited Count：1 Percentile：10.45(Nuclear Science & Technology)no abstracts in English
Katayama, Kazunari*; Takeishi, Toshiharu*; Manabe, Yusuke*; Nagase, Hiroyasu*; Nishikawa, Masabumi*; Miya, Naoyuki
Journal of Nuclear Materials, 340(1), p.83 - 92, 2005/04
Times Cited Count：8 Percentile：49.16(Materials Science, Multidisciplinary)no abstracts in English
Yang, X.; Tagawa, Akihiro; Ueda, Masashi; Yamashita, Takuya; Otsuka, Yusuke*; Osafune, Kazunori*; Nishikawa, Masahiro*
The Hellenic Society of N, 0 Pages, 2003/11
This paper describes a new structure of horizontally polarized shear(SH) wave electromagnetic acoustic transducer(EMAT). The EMAT with a Halbach magnet structure shows a stronger magnetic flux density as well as ultrasonic sound pressure than that of an EMAT with a general periodic permanent magnet(PPM) structure. The measured magnetic flux density and the ultrasound directivity distributions for both the Halbach and the PPM structure EMATs are in excellent agreement with those expected form a simulation calculation. The above EMATs were also used for inspection tests of many artificial slits; and it is found that the Halbach one performs a better detectability than the PPM one.
Otsuka, Yusuke*; Nishikawa, Masahiro*
JNC TY4400 2002-002, 59 Pages, 2002/03
JNC-TY4400-2002-002.pdf:3.84MB
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