Fluctuations in the scrape-off layer and edge plasma of the COMPASS tokamak

0492003 - ÚFP 2019 RIV CZ eng C - Conference Paper (international conference)
Seidl, Jakub - Jiráková, Kateřina - Adámek, Jiří - Grover, Ondřej - Horáček, Jan - Hron, Martin - Vondráček, Petr
Fluctuations in the scrape-off layer and edge plasma of the COMPASS tokamak.
Europhysics Conference Abstracts. Vol. 42A. European Physical Society, 2018 - (Coda, S.; Berndt, J.; Lapenta, G.; Mantsinen, M.; Michaut, C.; Weber, S.). ISBN 979-10-96389-08-7.
[45th European Physical Society Conference on Plasma Physics. Praha (CZ), 02.07.2018-06.07.2018]
R&D Projects: GA ČR(CZ) GA16-25074S; GA MŠMT(CZ) 8D15001; GA MŠMT(CZ) LM2015045
Institutional support: RVO:61389021
Keywords : plasma * tokamak * turbulence
OECD category: Fluids and plasma physics (including surface physics)
http://ocs.ciemat.es/EPS2018PAP/pdf/P1.1103.pdf

In this work we study properties of turbulent structures in the scrape-off layer (SOL) and edge plasma of the COMPASS tokamak. Two distinct types of coherent oscillations are observed: a) broadband high frequency branch rotating in the electron diamagnetic direction, appearing mainly in the confined region but protruding also to the SOL b) low-frequency blobs rotating in an opposite poloidal direction, formed in the vicinity of the radius of zero electric field. The transition region is localized in the near SOL, where both types spatially overlap and interact and the radial particle transport gradually transfers from high to low frequencies. Even though skewness of fluctuations of the ion saturation current is positive even inside LCFS, distinguishable Gamma-distributed PDF, formed by the low-frequency fluctuations, arises in the near SOL and most of the fluctuations that form a positive skewness in the edge region disappear around LCFS.
Permanent Link: http://hdl.handle.net/11104/0287755