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Iwamae, Atsushi; Sakaue, Atsushi*; Atake, Makoto*; Sawada, Keiji*; Goto, Motoshi*; Morita, Shigeru*
Plasma Physics and Controlled Fusion, 51(11), p.115004_1 - 115004_15, 2009/11
Times Cited Count:6 Percentile:24.17(Physics, Fluids & Plasmas)Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Kawashima, Hisato; Shimizu, Katsuhiro; Asakura, Nobuyuki
Plasma and Fusion Research (Internet), 4, p.025_1 - 025_7, 2009/08
The volume recombination in detached divertor plasmas is a key process to reduce the ion flux to the divertor plates. Two-dimensional measurement is one of the ways to investigate a spatial structure of the volume recombination. In this work, the deuterium Balmer-series lines from a detached divertor plasma were observed two-dimensionally with a spatial resolution of 1 cm and were reconstructed into two-dimensional emissivities with a tomography technique. The ratio of the D to the D
emissivity was compared to that calculated by the collisional-radiative model. This ratio could not be explained only by the excitation of D by electron impact, indicating that the volume recombination contributed to the D
emission. This is the case for the region above the inner strike point with 8 cm and 4 cm, respectively, in the r- and the z-direction on the poloidal cross-section.
Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Shimizu, Katsuhiro; Kawashima, Hisato; Asakura, Nobuyuki
Plasma and Fusion Research (Internet), 2, p.S1121_1 - S1121_4, 2007/11
Understanding deuterium particle behavior in the divertor plasma is necessary to study the ionizing and recombining plasmas. Two-dimensional spectroscopic measurement of deuterium emission is useful to understand deuterium particle behavior in divertor plasmas. The information of the ionization and recombination can be obtained by measurement of deuterium Balmer-series lines. A wide-spectral-band spectrometer with a CCD detector was used to observe deuterium Balmer-series lines with two-dimensional spatial distribution in the JT-60U divertor region. From the measurement, we can obtain a two-dimensional distribution of D and D
using a computer tomography technique. The D
emission was strong above the strike point in the inner divertor and around the strike point in the outer divertor. The D
emission was strong above the strike point in the inner divertor.
Kubo, Hirotaka; Takenaga, Hidenobu; Sawada, Keiji*; Nakano, Tomohide; Kobayashi, Shinji*; Higashijima, Satoru; Asakura, Nobuyuki; Shimizu, Katsuhiro
Journal of Nuclear Materials, 337-339, p.161 - 165, 2005/03
Times Cited Count:15 Percentile:70.18(Materials Science, Multidisciplinary)no abstracts in English
Kubo, Hirotaka; Takenaga, Hidenobu; Nakano, Tomohide; Higashijima, Satoru; Shimizu, Katsuhiro; Sawada, Keiji*; Kobayashi, Shinji*; JT-60 Team
Nuclear Fusion Research; Springer Series in Chemical Physics, Vol.78, p.121 - 134, 2004/11
no abstracts in English
Nakano, Tomohide; Fujimoto, Takashi*; Goto, Motoshi*; Hatayama, Akiyoshi*; Kado, Shinichiro*; Kato, Takako*; Kimura, Mineo*; Kubo, Hirotaka; Murakami, Izumi*; Ono, Noriyasu*; et al.
Annual Report of National Institute for Fusion Science; April 2003 - March 2004, P. 414, 2003/10
no abstracts in English
Kubo, Hirotaka; Sawada, Keiji*
Purazuma, Kaku Yugo Gakkai-Shi, 74(6), p.562 - 567, 1998/06
no abstracts in English
Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Shimizu, Katsuhiro; Sawada, Keiji*; Kawashima, Hisato; Asakura, Nobuyuki
no journal, ,
no abstracts in English
Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Kawashima, Hisato; Shimizu, Katsuhiro; Asakura, Nobuyuki
no journal, ,
The volume recombination in detached divertor plasmas is a key process to reduce the ion flux to the divertor plates. The deuterium Balmer-series lines (D, D
, ..., D
) from a detached divertor plasma were observed two-dimensionally with a spatial resolution of about 1 cm and were reconstructed with a tomography technique. The ratio of the D
to the D
emissivity was compared to that calculated by the collisional-radiative model. This ratio could not be explained only by the excitation of D by electron impact, indicating that the volume recombination contributed to the D
emission. This is the case for the region above the inner strike point with about 8 cm and 4 cm, respectively, in the r- and the z-direction on the poloidal cross-section. In this region, from the ratios of the D
, D
, ..., D
emissivities, the electron density and temperature were evaluated to be about 1
10
m
and less than 0.3 eV, respectively.
Idei, Ryo*; Sawada, Keiji*; Hoshino, Kazuo; Asakura, Nobuyuki
no journal, ,
no abstracts in English
Nakashima, Yosuke*; Ichimura, Kazuya*; Takeda, Hisahito*; Iwamoto, Miki*; Hosoda, Yasunari*; Shimizu, Keita*; Oki, Kensuke*; Sakamoto, Mizuki*; Ono, Noriyasu*; Kado, Shinichiro*; et al.
no journal, ,
no abstracts in English