TY - JOUR
T1 - Cross-field motion of plasma blob-filaments and related particle flux in an open magnetic field line configuration on QUEST
AU - Liu, H. Q.
AU - Hanada, K.
AU - Nishino, N.
AU - Ogata, R.
AU - Ishiguro, M.
AU - Gao, X.
AU - Zushi, H.
AU - Nakamura, K.
AU - Fujisawa, A.
AU - Idei, H.
AU - Hasegawa, M.
PY - 2013
Y1 - 2013
N2 - Blob-filaments have been observed by combined measurement with a fast camera and a movable Lang-muir probe in an open magnetic field line configuration of electron cyclotron resonance (ECR) heating plasma in QUEST. Blob-filaments extended along field lines do correspond to over-dense plasma structures and propagated across the field lines to the outer wall. The radial velocity of the blob structure, Vb, was obtained by three methods and was dominantly driven by the E × B force. The radial velocity, size of the blob showed good agreements with the results obtained by sheath-connected interchange theoretical model. Vb corresponds to roughly 0.02-0.07 of the local sound speed (Cs) in QUEST. The higher moments (skewness S and kurtosis K) representing the shape of PDF of density fluctuation are studied. Their least squares fitting with quadratic polynomial is K= (1.60 ± 0.27)S2 - (0.46 ± 0.20). The larger blob structures, occurring only 10% of the time, can carry more than 60% loss of the entire radial particle flux.
AB - Blob-filaments have been observed by combined measurement with a fast camera and a movable Lang-muir probe in an open magnetic field line configuration of electron cyclotron resonance (ECR) heating plasma in QUEST. Blob-filaments extended along field lines do correspond to over-dense plasma structures and propagated across the field lines to the outer wall. The radial velocity of the blob structure, Vb, was obtained by three methods and was dominantly driven by the E × B force. The radial velocity, size of the blob showed good agreements with the results obtained by sheath-connected interchange theoretical model. Vb corresponds to roughly 0.02-0.07 of the local sound speed (Cs) in QUEST. The higher moments (skewness S and kurtosis K) representing the shape of PDF of density fluctuation are studied. Their least squares fitting with quadratic polynomial is K= (1.60 ± 0.27)S2 - (0.46 ± 0.20). The larger blob structures, occurring only 10% of the time, can carry more than 60% loss of the entire radial particle flux.
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U2 - 10.1016/j.jnucmat.2013.01.106
DO - 10.1016/j.jnucmat.2013.01.106
M3 - Article
AN - SCOPUS:84885473382
SN - 0022-3115
VL - 438
SP - S513-S517
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - SUPPL
ER -