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Kawashima, Hisato; Sengoku, Seio; Uehara, Kazuya; Tamai, Hiroshi; Shoji, Teruaki*; Ogawa, Hiroaki; Shibata, Takatoshi; Yamamoto, Masahiro*; Miura, Yukitoshi; Kusama, Yoshinori; et al.
Fusion Science and Technology, 49(2), p.168 - 186, 2006/02
Times Cited Count：3 Percentile：24.46(Nuclear Science & Technology)Experimental efforts on JFT-2M have been devoted to understand SOL/Divertor plasmas and to investigate power and particle controllability. Open divertor configuration was used for the first decade of JFT-2M started in 1984. We found out the SOL/Divertor plasma properties such as in/out asymmetry, heat and particle diffusivities, and SOL current at ELMs. Handling of power and particle was demonstrated by active control methods such as local pumping, edge ergodization, divertor biasing, and edge heating. For improvement of power and particle control capability of divertor, it was modified to closed configuration in 1995, which demonstrated the baffling effects with narrower divertor throat. Dense and cold divertor state (n
= 4
10
m
and T = 4 eV), compatible with the improved confinement modes (e.g. H-mode), was realized by strong gas puffing. Being related with the core confinement at H-mode, the edge plasma fluctuations were identified by an electrostatic probe. These are reviewed in this paper.
Amemiya, Hiroshi*; Uehara, Kazuya
Japanese Journal of Applied Physics, Part 1, 45(1A), p.247 - 249, 2006/01
Times Cited Count：4 Percentile：17.24(Physics, Applied)A method for detecting the separatrix surface in the edge plasma in Tokamak is presented. Two sets of double probes whose front surfaces are shifted by a small distance are mounted and the difference of the currents is measured using a differential amplifier. When the separatrix surface reaches the probes, a current increment appears in the differential amplifier, giving a signal of the arrival of the separatrix. Procedures of obtaining plasma parameters including the ion temperature are described.
Ishii, Yasuyuki; Isoya, Akira*; Kojima, Takuji
Nuclear Instruments and Methods in Physics Research B, 210, p.70 - 74, 2003/09
Times Cited Count：13 Percentile：65.11(Instruments & Instrumentation)The conception for this microbeam formation, which consists in combining beam contraction effect of acceleration process with the lens action, was published in 1991. The test machine was installed in JAERI. The study of reducing beam size showed that the incident beam condition strongly depend on its size. Recently about 40 keV stable microbeam 
of 0.1 
m order in radius has been obtained after optimizing the ion beam injection system. The test machine is composed of a duoplasmatron-type discharge source, an initial acceleration system, a main acceleration lens system, and microbeam diameter measurement system. We will present the schematic of the test machine and the result of the beam size measurement. Performance of the system will also show to depend mostly on how nicely a low energy injection beam is prepared at the entrance region.
Chankin, A. V.; Asakura, Nobuyuki; Fukuda, Takeshi; Isayama, Akihiko; Itami, Kiyoshi; Kamada, Yutaka; Kubo, Hirotaka; Miura, Yukitoshi; Nakano, Tomohide; Oyama, Naoyuki; et al.
Journal of Nuclear Materials, 313-316, p.828 - 833, 2003/03
Times Cited Count：21 Percentile：79.04(Materials Science, Multidisciplinary)In JT-60U, extensive plasma-neutral exchange during a typical type I ELM leads to a transient increase in the total number of charged particles in the plasma. The density rise is especially large at the edge, with the increase in the inner vertical interferometer signal (FIR1) of up to 40%, in the case of a giant ELM. Fast measurements of edge plasma density, electron temperature, magnetic fluctuations and Bremsstrahlung emission have been conducted to study the dynamics of the ELM evolution. In order to pinpoint the exact location of the density rise, a dedicated set of experiments with the horizontal plasma sweep to scan the separatrix position at the inner midplane with respect to the FIR1 chord, has been carried out at different wall conditions.
Ozeki, Takahisa; M.S.Chu*; L.L.Lao*; T.S.Taylor*; M.S.Chance*; *; K.H.Burrell*; R.D.Stambaugh*
Nuclear Fusion, 30(8), p.1425 - 1432, 1990/08
Times Cited Count：112 Percentile：93.07(Physics, Fluids & Plasmas)no abstracts in English
