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Faenov, A.*; Matsubayashi, Masahito; Pikuz, T.*; Fukuda, Yuji; Kando, Masaki; Yasuda, Ryo; Iikura, Hiroshi; Nojima, Takehiro; Sakai, Takuro; Shiozawa, Masahiro*; et al.
High Power Laser Science and Engineering, 3, p.e27_1 - e27_9, 2015/10
Times Cited Count：10 Percentile：49.69(Optics)Sugie, Tatsuo
Purazuma Shindan No Kiso To Oyo, p.116 - 131, 2006/03
Radiation from the plasma degrades the performance of energy confinement. In addition, the efficiency of fusion reaction will be decreased by the fuel dilution due to the impurity ions in the plasma. Therefore, the impurity control (generation, reduction of the contamination, exhaust) becomes an important research subject. Spectroscopic diagnostics is the one of the most important methods to study such subjects. On the other hand, it is also utilized for the measurements of plasma parameters such as ion temperature, plasma current distribution etc. In this section, the radiation behavior and the spectroscopic diagnostics of high temperature plasma are described.
Kasai, Satoshi*; Kamiya, Kensaku; Shinohara, Koji; Kawashima, Hisato; Ogawa, Hiroaki; Uehara, Kazuya; Miura, Yukitoshi; Okano, Fuminori; Suzuki, Sadaaki; Hoshino, Katsumichi; et al.
Fusion Science and Technology, 49(2), p.225 - 240, 2006/02
Times Cited Count：3 Percentile：24.11(Nuclear Science & Technology)The diagnostic system of JFT-2M has consisted of about 30 individual diagnostic instruments,which were used to study the plasma production, control, equilibrium, stability, confinement, plasma heating by NBI and/or RF (LH, ICRF, ECH) and current drive by RF. In these instruments, the motional Stark effect (MSE) polarimeter, charge exchanged recombination spectroscopy (CXRS), heavy-ion beam probe (HIBP), time of flight (TOF) neutral particle analyzer, etc. have contributed to make clear the improved mechanism of confinement such as H-mode and High Recycling Steady (HRS) H-mode, and to search the operational region of these modes.The infrared TV camera system and lost ion probe have played a very important role to investigate the heat load onto the walls due to ripple loss particles and escaping ions from core plasma, respectively.
Kondoh, Takashi; Costley, A. E.*; Sugie, Tatsuo; Kawano, Yasunori; Malaquias, A.*; Walker, C. I.*
Review of Scientific Instruments, 75(10), p.3420 - 3422, 2004/10
Times Cited Count：23 Percentile：72.22(Instruments & Instrumentation)In order to measure the line average electron density on ITER, a CO
laser interferometer/polarimeter system is being developed. The design of the interferometer/polarimeter is improved from the previous design, which uses CO and CO laser, on the basis of experience gained with a dual CO system on JT-60U in which good reliability was confirmed for both interferometry and polarimetry operation. The performance of the dual CO laser meets requirements for ITER (accuracy; 1%, time resolution; 1 ms).
Nishitani, Takeo; Vayakis, G.*; Yamauchi, Michinori*; Sugie, Tatsuo; Kondoh, Takashi; Shikama, Tatsuo*; Ishitsuka, Etsuo; Kawashima, Hisato
Journal of Nuclear Materials, 329-333(Part2), p.1461 - 1465, 2004/08
Times Cited Count：16 Percentile：70(Materials Science, Multidisciplinary)no abstracts in English
Takatsu, Hideyuki; Sato, Kazuyoshi; Hamada, Kazuya; Nakahira, Masataka; Suzuki, Satoshi; Nakajima, Hideo; Kuroda, Toshimasa*; Nishitani, Takeo; Shikama, Tatsuo*; Shu, Wataru
Journal of Nuclear Materials, 329-333(1), p.178 - 182, 2004/08
Times Cited Count：2 Percentile：17.18(Materials Science, Multidisciplinary)This paper presents an overview on ITER-supporting materials research and development activities and major achievements in Japan during the period from the Co-ordinated Technical Activities to date. In view of the completed engineering design of ITER during the Engineering Design Activities period, research and development efforts since then have been focused: those for reduction of component fabrication cost; those in support of domestic preparations of a structural technical code for construction; those necessary for operation, and been extended to component-level testing rather than pure material testing. They cover materials Research and Development for in-vessel components, vacuum vessel, cryogenic steels of superconducting mgnet and diagnostics components. Major achievements in each research and development area are highlighted and their impact or implication to the design, construction and operation of ITER is presented.
Mironov, M. I.*; Khudoleev, A. V.*; Kusama, Yoshinori
Plasma Physics Reports, 30(2), p.164 - 168, 2004/02
Times Cited Count：0 Percentile：0.02(Physics, Fluids & Plasmas)High-energy charge-exchange diagnostics can determine the distribution function of fast atoms produced via the neutralization of hydrogen ions by hydrogen-like impurity ions. Deriving the distribution function requires to know the composition and spatial distribution of the target ions in a plasma. A charge-exchange target forms as a result of the interaction between impurity nuclei and beam atoms. Depending on the arrangement of heating beams with respect to the diagnostics, it is necessary to calculate their trajectories. A model which takes into account elementary processes resulting in the ionization equilibrium of the ions of impurities in a specific tokamak configuration is proposed. The model is applied to the JT-60U plasma. Mechanisms for the formation of charge-exchange atomic flows are considered. The relative contributions of different heating injectors to the charge-exchange flow are estimated. Based on the calculated results, a method is proposed for local measurements of the ion distribution function with a stationary analyzer.
Nishitani, Takeo; Ebisawa, Katsuyuki*; Kasai, Satoshi; Walker, C.*
Review of Scientific Instruments, 74(3), p.1735 - 1738, 2003/03
Times Cited Count：14 Percentile：58.66(Instruments & Instrumentation)no abstracts in English
laser for ion energy spectrum measurements in JT-60UKondoh, Takashi; Miura, Yukitoshi; Lee, S.*; Richards, R. K.*; Hutchinson, D. P.*; Bennett, C. A.*
Review of Scientific Instruments, 74(3), p.1642 - 1645, 2003/03
Times Cited Count：20 Percentile：68.22(Instruments & Instrumentation)Measurements of energy spectrum and density profile of confined alpha-particles are required for ITER. Several methods have been proposed, however, a measurement technique hasn't been established yet. A collective Thomson scattering (CTS) system based on a pulsed CO laser is being developed to demonstrate feasibility of alpha-particle diagnostics for ITER. The pulse laser (15J, 1
m, 0.6 m) and a wide band (~ 8GHz) heterodyne receiver with a quantum-well infrared photodetector (QWIP) have been developed and installed in the JT-60U tokamak. Stray light is reduced by a notch filter with hot CO gas. Heterodyne receiver is absolutely calibrated using large area blackbody radiation source. Scattered signal from JT-60U plasma has not detected because of electrical noise originated from discharge of the pulsed laser and stray signal caused by impurity of the spectrum of the pulsed laser.
Peterson, B. J.*; Ashikawa, Naoko*; Konoshima, Shigeru; Ingesson, L. C.*; Walker, C. I.*
Proceedings of 30th EPS Conference on Controlled Fusion and Plasma Physics (CD-ROM), 4 Pages, 2003/00
Research and development of imaging bolometers has progressed from the Segmented Mask IR Imaging Bolometer to the IR Imaging Video Bolometer (IRVB). Meanwhile tests of conventional resistive bolometers have shown their weakness to the high neutron flux. In this paper we compare the IRVBs currently installed in the Large Helical Device with a conceptual design for the JT-60U tokamak and a feasibility study for the International Thermonuclear Experimental Reactor. Comparisons are made with conventional resistive bolometers in terms of sensitivity, spatial and time resolution, port access requirements, steady-state operation, long term durability and shielding of stray ECH power.
Nishitani, Takeo; Sugie, Tatsuo; Kasai, Satoshi; Kaneko, Junichi*; Yamamoto, Shin
Journal of Nuclear Materials, 307-311(Part2), p.1264 - 1267, 2002/12
Times Cited Count：23 Percentile：79.51(Materials Science, Multidisciplinary)no abstracts in English
Sugie, Tatsuo; Hatae, Takaki; Koide, Yoshihiko; Fujita, Takaaki; Kusama, Yoshinori; Nishitani, Takeo; Isayama, Akihiko; Sato, Masayasu; Shinohara, Koji; Asakura, Nobuyuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.482 - 511, 2002/09
Times Cited Count：6 Percentile：3.03(Nuclear Science & Technology)The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so that the internal structure of plasmas has been explored. The understanding of plasma confinement has been enhanced by density and temperature fluctuation measurements using a mm-wave reflectometer and electron cyclotron emission measurements respectively. In addition, the real-time control experiments of electron density, neutron yield, radiated power and electron temperature gradient have been carried out successfully by corresponding diagnostic devices. These measurements and the real time control contribute to improving plasma performance. Diagnostic devices for next generation fusion devices such as a CO2 laser interferometer/polarimeter and a CO2 laser collective Thomson scattering system have been developed.
Nishitani, Takeo; Ebisawa, Katsuyuki*; Walker, C.*; Kasai, Satoshi
JAERI-Tech 2001-066, 57 Pages, 2001/10
JAERI-Tech-2001-066.pdf:1.89MB
no abstracts in English
laser in JT-60UKondoh, Takashi; Lee, S.; Miura, Yukitoshi
Proceedings of 10th International Symposium on Laser-Aided Plasma Diagnostics, p.109 - 114, 2001/00
A collective Thomson scattering (CTS) diagnostic system based on a CO laser has come into operation to establish measurement technique of ion temperature and fast alpha particle in fusion plasmas. A pulsed CO2 laser (wavelength 10.6m, beam energy 15 J, pulse width 1s) and a heterodyne receiver were developed by Oak Ridge National Laboratory (ORNL) and were installed in the JT-60U tokamak. Commissioning of the CTS system by injecting the CO laser into the plasmas has been proceeded.
Department of Fusion Plasma Research
JAERI-Conf 2000-007, p.161 - 0, 2000/03
JAERI-Conf-2000-007.pdf:9.11MB
no abstracts in English
Zushi, Hideki*; Sugie, Tatsuo; Kusama, Yoshinori; Sasao, Mamiko*; Mitarai, Osamu*; Nishitani, Takeo; Nagashima, Akira; Muraoka, Katsunori*
Purazuma, Kaku Yugo Gakkai-Shi, 76(2), p.145 - 162, 2000/02
no abstracts in English
Hoek, M.; Nishitani, Takeo; Takahashi, Hiroyuki*; Nakazawa, Masaharu*; Elevant, T.*; Shibata, Yasunari
JAERI-Research 99-062, p.28 - 0, 1999/11
JAERI-Research-99-062.pdf:1.51MB
no abstracts in English
Nishitani, Takeo; L.C.Johnson*; Ebisawa, Katsuyuki*; C.Walker*; Ando, Toshiro; Kasai, Satoshi
Review of Scientific Instruments, 70(1), p.1141 - 1144, 1999/01
Times Cited Count：15 Percentile：68.26(Instruments & Instrumentation)no abstracts in English
ITER Physics Expert Group on Diagnostics
Nuclear Fusion, 39(12), p.2541 - 2575, 1999/00
no abstracts in English
*; Oyama, Yukio; *; Maekawa, Fujio; Ikeda, Yujiro
Fusion Engineering and Design, 41, p.207 - 212, 1998/00
Times Cited Count：2 Percentile：24.49(Nuclear Science & Technology)no abstracts in English
