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-ion beams for ITER neutral beam systemTaniguchi, Masaki; Inoue, Takashi; Kashiwagi, Mieko; Watanabe, Kazuhiro; Hanada, Masaya; Seki, Takayoshi*; Dairaku, Masayuki; Sakamoto, Keishi
Review of Scientific Instruments, 77(3), p.03A514_1 - 03A514_4, 2006/03
Times Cited Count：14 Percentile：56.68(Instruments & Instrumentation)In the ITER NB systems, conventional gas insulation technology cannot be utilized because of the conductivity of the insulation gas caused by the radiation from the tokamak plasma. To overcome this problem, a vacuum insulated beam source (VIBS), where the whole beam source is immersed in vacuum, has been developed in JAERI. Recently, voltage holding capability of the VIBS was drastically improved by installing the large stress ring and these progress enables us to perform the high power operation of the VIBS accelerator. For high current density H- beam acceleration, modifications were made on KAMABOKO source. At present, H- beam current density is 146 A/m
at 836 keV (input arc power; 40 kW, operation pressure; 0.3 Pa).The acceleration of 900 keV, 0.1 A level beam was accomplished for 175 shots during the test campaign. The beam acceleration was quite stable and the degradation of the voltage holding due to the beam acceleration and/or Cs seeding was not observed.
Otani, Eiji*; Suzuki, Akio*; Ando, Ryota*; Urakawa, Satoru*; Funakoshi, Kenichi*; Katayama, Yoshinori
Advances in High-Pressure Technology for Geophysical Applications, p.195 - 209, 2005/09
This paper summarizes the techniques for the viscosity and density measurements of silicate melt and glasses at high pressure and temperature by using the X-ray radiography and absorption techniques in the third generation synchrotron radiation facility, SPring-8, Japan. The falling sphere method using in situ X-ray radiography makes it possible to measure the viscosity of silicate melts to the pressures above 6 GPa at high temperature. We summarize the details of the experimental technique of the viscosity measurement, and the results of the measurements of some silicate melts such as the albite and diopside-jadeite systems. X-ray absorption method is applied to measure the density of the silicate glasses such as the basaltic glass and iron sodium disilicate glass up to 5 GPa at high temperature. A diamond capsule, which is not reactive with the glass, is used for the density measurement of the glasses. The present density measurement of the glasses indicates that this method is useful for measurement of the density of silicate melts at high pressure and temperature.
Higuchi, Kensuke*; Kimura, Kakuryo*; Mizuno, Akitoshi*; Watanabe, Masahito*; Katayama, Yoshinori; Kuribayashi, Kazuhiko*
Measurement Science and Technology, 16(2), p.381 - 385, 2005/02
Times Cited Count：43 Percentile：87.11(Engineering, Multidisciplinary)X-ray diffraction and density measurements have been simultaneously performed to investigate the atomic structure of molten silicon in wide temperature range including undercooling region by using the electromagnetic levitation technique. The density was obtained from the mass and the shape of levitated sample by non-contact method based on the image analysis technique. X-ray diffraction experiments were performed by using the synchrotron radiation at SPring8, Japan. From structural analysis of undercooled molten silicon, first nearest neighbour coordination numbers and interatomic distances were about 5 and 2.48
with no dependence on temperature in the range of 1900-1550 K. We conclude as a result that the short-range order based on tetrahedral bonds of undercooled molten silicon does not change with the degree of undercoolings but medium-range order changes by the degree of undercoolings.
Katayama, Yoshinori; Inamura, Yasuhiro*; Mizutani, Takeshi*; Yamakata, Masaaki*; Utsumi, Wataru; Shimomura, Osamu*
Science, 306(5697), p.848 - 851, 2004/10
Times Cited Count：148 Percentile：96.71(Multidisciplinary Sciences)Structural transformation between two liquid structures of phosphorus that occurred at about 1 GPa and 1000
C was investigated by in-situ X-ray radiography. When the low-pressure liquid was compressed, dark and round objects appeared in the radiograph. X-ray diffraction measurements confirmed that these objects were the high-pressure liquid. The drops grew and eventually filled the sample space. Decompressing caused the reverse process. The macroscopic phase separation supported the view that it was a first-order liquid-liquid phase transition. X-ray absorption measurements revealed that the change in density at the transition is about 40 % of the density of the high-pressure liquid.
Higashijima, Satoru; Asakura, Nobuyuki; Kubo, Hirotaka; Miura, Yukitoshi; Nakano, Tomohide; Konoshima, Shigeru; Itami, Kiyoshi; Sakurai, Shinji; Takenaga, Hidenobu; Tamai, Hiroshi; et al.
Journal of Nuclear Materials, 313-316, p.1123 - 1130, 2003/03
Times Cited Count：17 Percentile：72.74(Materials Science, Multidisciplinary)Reduction of steady-state heat load in the divertor and transient one by ELMs is a crucial issue for tokamak fusion devices. High radiation loss power is necessary for the heat load reduction, and the conventional gas puffing can increase the density and the radiation loss power, but it degrades the confinement. Core plasma with high confinement should be maintained simultaneously. Impurity seeding is a secure way to enhance the radiation loss power. In JT-60U, heat load is successfully reduced by Ar injection with keeping a high confinement in ELMy H-mode plasmas. In this paper, heat load reduction, radiation enhancement, and change of ELM activity are discussed.
Katayama, Yoshinori; Inamura, Yasuhiro
Journal of Physics; Condensed Matter, 15(1), p.S343 - S350, 2003/01
Times Cited Count：16 Percentile：61.23(Physics, Condensed Matter)Combination of synchrotron radiation sources and large volume presses enable us to make in-situ observations of structural change in liquids and glasses at high pressures up to several GPa and high temperatures up to 1500K. A number of methods, X-ray diffraction, XAFS, density measurement by means of X-ray absorption, viscosity measurements by means of radiography, are now applicable for this purpose. We have systematically studied elemental liquid and found that a characteristic structural change occurs in a narrow pressure-temperature range in liquid selenium. Moreover we have found a sudden structural change in liquid phosphorus. Experimental results on phosphorus support a view that the change is a first-order liquid-liquid transition. In the talk, results of current attempt to detect sudden structural change in silica glass will be presented. A preliminary result of X-ray diffraction study on liquid water under high-pressure will be also reported.
Lemehov, S.; Nakamura, Jinichi; Suzuki, Motoe
Nuclear Technology, 133(2), p.153 - 168, 2001/02
Times Cited Count：9 Percentile：56.08(Nuclear Science & Technology)no abstracts in English
Cu
O
; Okayasu, Satoru; *
Superconductors, Surfaces and Superlattices (Trans. of Materials Research Soc. Jpn., Vol. 19A), 0, p.413 - 416, 1994/00
no abstracts in English
Yanagisawa, Kazuaki; Ugajin, Mitsuhiro; *
Kaku Nenryo Kogaku; Genjo To Tembo, p.285 - 304, 1993/11
no abstracts in English
*; Wachi, Y.*; Shimada, M.*; *; *; Hamajima, Takataro*; Fujioka, T.*; Nishi, Masataka; Tsuji, Hiroshi; Ando, Toshinari; et al.
IEEE Transactions on Applied Superconductivity, 3(1), p.480 - 483, 1993/03
Times Cited Count：4 Percentile：45.56(Engineering, Electrical & Electronic)no abstracts in English
Aoki, Nobuo*; *; *; *; Shimada, M.*; Hamajima, Takataro*; *; Fujioka, T.*; Takahashi, Yoshikazu; Ando, Toshinari; et al.
Cryogenics, 33(6), p.581 - 585, 1993/00
Times Cited Count：2 Percentile：17.83(Thermodynamics)no abstracts in English
Shiratori, Tetsuo; Fukuda, Kosaku
Journal of Nuclear Materials, 202, p.98 - 103, 1993/00
Times Cited Count：13 Percentile：76.59(Materials Science, Multidisciplinary)no abstracts in English
Yamamoto, Keiichi*; Yoshida, Kiyoshi; Yasukawa, Yukio*; Tsukamoto, Hideo*; Sasaki, Takashi*; Okuno, Kiyoshi; Nishi, Masataka; Koizumi, Norikiyo; Isono, Takaaki; Sugimoto, Makoto; et al.
Proc. of the 17th Symp. on Fusion Technology, 0, p.971 - 975, 1993/00
no abstracts in English
Tanaka, Shigeru; Ohira, Tatsuya*; Nakamura, Kazuyuki
Journal of Nuclear Materials, 196-198, p.357 - 362, 1992/12
Times Cited Count：0 Percentile：0.01(Materials Science, Multidisciplinary)no abstracts in English
Nishimura, Akihiko; Oba, Hironori; Shibata, Takemasa
Journal of Nuclear Science and Technology, 29(11), p.1054 - 1060, 1992/11
no abstracts in English
Nishi, Masataka; Ando, Toshinari; Tsuji, Hiroshi; *; Hamajima, Takataro*; Fujioka, T.*
Teion Kogaku, 27(3), p.207 - 216, 1992/00
no abstracts in English
Aoki, Nobuo*; *; *; *; Shimada, M.*; Hamajima, Takataro*; *; Fujioka, T.*; Takahashi, Yoshikazu; Ando, Toshinari; et al.
Teion Kogaku, 27(3), p.221 - 225, 1992/00
no abstracts in English
Nishi, Masataka; Tsuji, Hiroshi; Takahashi, Yoshikazu; Nakajima, Hideo; Isono, Takaaki; Ando, Toshinari; Shimamoto, Susumi; *; Hamajima, Takataro*; *; et al.
Proc. of the 11th Int. Conf. on Magnet Technology,Vol. 2, p.856 - 861, 1990/00
no abstracts in English
*; Hanada, Masaya; Inoue, Takashi; Kojima, Hiroaki; Ohara, Yoshihiro; Okumura, Yoshikazu; Watanabe, Kazuhiro
Proceedings of the 12th Symposium on Ion Sources and Ion-Assisted Technology, p.107 - 110, 1989/00
no abstracts in English
Akabori, Mitsuo; Shiba, Koreyuki
JAERI-M 84-167, 15 Pages, 1984/09
no abstracts in English
