TY - JOUR
T1 - Development of ion sensitive probe and its application to RF plasma device DT-ALPHA
AU - Kobayashi, Takahiko
AU - Takahashi, Hiroyuki
AU - Kitajima, Sumio
AU - Okamoto, Atsushi
AU - Tobita, Kenji
AU - Boonyarittipong, Peerapat
AU - Saikyo, Takeshi
AU - Ishikawa, Yusuke
AU - Ogasawara, Kenta
AU - Hashizume, Hidetoshi
N1 - Publisher Copyright:
© 2019 The Japan Society of Plasma Science and Nuclear Fusion Research.
PY - 2018
Y1 - 2018
N2 - An ion sensitive probe was developed and introduced into the radio-frequency (RF) plasma source DTALPHA. The collector current was investigated by changing the position of the recessed collector electrode and the offset voltage to optimize these two parameters for ion temperature evaluation. It was found that the ion temperature could be overestimated when the retardation of bulk electrons is insufficient. In addition, it was also found that secondary electron emission from the collector surface results in overestimation of ion temperature. The dependence of ion temperature on RF heating power was then investigated. The ion temperature increased, and the ratio of ion temperature and electron temperature became close to 1 as RF power increased. This trend could be interpreted as a temperature relaxation between ions and electrons. The ion temperature dependence on neutral pressure was also investigated. Ion temperature monotonically decreased with increasing neutral pressure.
AB - An ion sensitive probe was developed and introduced into the radio-frequency (RF) plasma source DTALPHA. The collector current was investigated by changing the position of the recessed collector electrode and the offset voltage to optimize these two parameters for ion temperature evaluation. It was found that the ion temperature could be overestimated when the retardation of bulk electrons is insufficient. In addition, it was also found that secondary electron emission from the collector surface results in overestimation of ion temperature. The dependence of ion temperature on RF heating power was then investigated. The ion temperature increased, and the ratio of ion temperature and electron temperature became close to 1 as RF power increased. This trend could be interpreted as a temperature relaxation between ions and electrons. The ion temperature dependence on neutral pressure was also investigated. Ion temperature monotonically decreased with increasing neutral pressure.
KW - Divertor
KW - Ion sensitive probe
KW - Ion temperature
KW - RF plasma
KW - Temperature relaxation
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U2 - 10.1585/PFR.13.3401090
DO - 10.1585/PFR.13.3401090
M3 - Article
AN - SCOPUS:85062099391
SN - 1880-6821
VL - 13
JO - Plasma and Fusion Research
JF - Plasma and Fusion Research
M1 - 3401090
ER -