TY - JOUR
T1 - Difference in oxygen impurity behavior between repetitive short discharges and one long discharge on TRIAM-1M
AU - Ogawa, M.
AU - Sakamoto, M.
AU - Sato, K. N.
AU - Zushi, H.
AU - Nakamura, K.
AU - Hanada, K.
AU - Idei, H.
AU - Hasegawa, M.
AU - Kawasaki, S.
AU - Nakashima, H.
AU - Higashijima, A.
N1 - Funding Information:
The authors would like to thank Dr Tanabe for his valuable advice. This work has been partially performed under the framework of joint-use research in RIAM Kyushu University and the bi-directional collaboration organized by NIFS. This work is partially supported by a Grant-in-Aid for Scientific Research from Ministry of Education, Science and Culture of Japan.
PY - 2007/6/15
Y1 - 2007/6/15
N2 - Oxygen impurity behaviors of one long duration discharge and repetition of short duration discharges have been investigated in TRIAM-1M. In the former case, the OII line intensity divided by the line averaged electron density, which is considered as a monitor of oxygen concentration on the plasma facing surface (PFS), decreased with the time constant, τd, of 30-50 s during the discharge due to the hydrogen flux to PFS. In the latter case, τd is in the range of 70-600 s. There exists a big difference of global behavior of oxygen impurity between both cases. The difference seems to result from the absence or presence of the interval time between the discharges. The oxygen concentration on PFS increases during the interval time due to adsorption of H2O. The time constant of the increase in the oxygen concentration is evaluated to be about 5500 s from Langmuir adsorption isotherms analysis.
AB - Oxygen impurity behaviors of one long duration discharge and repetition of short duration discharges have been investigated in TRIAM-1M. In the former case, the OII line intensity divided by the line averaged electron density, which is considered as a monitor of oxygen concentration on the plasma facing surface (PFS), decreased with the time constant, τd, of 30-50 s during the discharge due to the hydrogen flux to PFS. In the latter case, τd is in the range of 70-600 s. There exists a big difference of global behavior of oxygen impurity between both cases. The difference seems to result from the absence or presence of the interval time between the discharges. The oxygen concentration on PFS increases during the interval time due to adsorption of H2O. The time constant of the increase in the oxygen concentration is evaluated to be about 5500 s from Langmuir adsorption isotherms analysis.
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U2 - 10.1016/j.jnucmat.2007.01.238
DO - 10.1016/j.jnucmat.2007.01.238
M3 - Article
AN - SCOPUS:34248567078
SN - 0022-3115
VL - 363-365
SP - 1364
EP - 1368
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 1-3
ER -