TY - JOUR
T1 - Permeation measurements for investigating atomic hydrogen flux and wall pumping/fuelling dynamics in QUEST
AU - Sharma, S. K.
AU - Zushi, H.
AU - Takagi, I.
AU - Hisano, Y.
AU - Shikama, T.
AU - Morita, S.
AU - Tanabe, T.
AU - Yoshida, N.
AU - Sakamoto, M.
AU - Higashizono, Y.
AU - Hanada, K.
AU - Hasegawa, M.
AU - Nakamura, K.
AU - Idei, H.
AU - Sato, K. N.
AU - Kawasaki, S.
AU - Nakashima, H.
AU - Higashijima, A.
AU - Nakashima, Y.
AU - Hatano, Y.
AU - Sagara, A.
AU - Nakamura, Y.
AU - Ashikawa, N.
AU - Maekawa, T.
AU - Kishimoto, Y.
AU - Takase, Y.
N1 - Funding Information:
This work is performed with the support and under the auspices of the NIFS Collaboration Research Program (NIFS08KOBR002). This work is also partially supported by a Grant-in-aid for Scientific Research for Priority Area 476, “Tritium Science and Technology for Fusion Reactor.” One of the authors (H.Z.) appreciates emeritus professor Nishikawa for his continuous encouragement and interest for the present work.
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/1
Y1 - 2012/1
N2 - In order to investigate the overall atomic hydrogen background and the dynamic characteristics of wall pumping/fuelling phenomenon, a permeation probe system has been developed and applied in the spherical tokamak QUEST. Reliability of measurements, within ±3% accuracy and a positive correlation with the hydrogen line emission over three orders of magnitude have been demonstrated for more than 3000 various plasma discharges. By comparison of the experimental permeation (flux) curves with the numerically simulated curves, the net incident atomic hydrogen flux is evaluated in the range of 1 × 10 19 H m -2 s -1 to 4 × 10 20 H m -2 s -1. The atomic flux has been investigated as a function of various plasma operation parameters like RF power, gas pressure and magnetic configuration. Using the static particle balance and permeation measurements, the progress in wall conditioning has been investigated. An inverse correlation between the atomic hydrogen flux and improvement in wall pumping has been observed over the two campaigns.
AB - In order to investigate the overall atomic hydrogen background and the dynamic characteristics of wall pumping/fuelling phenomenon, a permeation probe system has been developed and applied in the spherical tokamak QUEST. Reliability of measurements, within ±3% accuracy and a positive correlation with the hydrogen line emission over three orders of magnitude have been demonstrated for more than 3000 various plasma discharges. By comparison of the experimental permeation (flux) curves with the numerically simulated curves, the net incident atomic hydrogen flux is evaluated in the range of 1 × 10 19 H m -2 s -1 to 4 × 10 20 H m -2 s -1. The atomic flux has been investigated as a function of various plasma operation parameters like RF power, gas pressure and magnetic configuration. Using the static particle balance and permeation measurements, the progress in wall conditioning has been investigated. An inverse correlation between the atomic hydrogen flux and improvement in wall pumping has been observed over the two campaigns.
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U2 - 10.1016/j.jnucmat.2011.09.026
DO - 10.1016/j.jnucmat.2011.09.026
M3 - Article
AN - SCOPUS:80054098791
SN - 0022-3115
VL - 420
SP - 83
EP - 93
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 1-3
ER -