Reynolds stress and fluctuation measurements with Langmuir and ball-pen probes in the vicinity of the L-H transition on COMPASS.

0482694 - ÚFP 2018 RIV FR eng C - Konferenční příspěvek (zahraniční konf.)
Grover, Ondřej - Seidl, Jakub - Adámek, Jiří - Vondráček, Petr - Tomeš, Matěj - Weinzettl, Vladimír - Hron, Martin - Pánek, Radomír
Reynolds stress and fluctuation measurements with Langmuir and ball-pen probes in the vicinity of the L-H transition on COMPASS.
EPS 2017: 44th European Physical Society Conference on Plasma Physics. Vol. 41F. Mulhouse: European Physical Society, 2017 - (Fajardo, M.; Westerhof, E.; Riconda, C.; Melzer, A.; Bret, A.; Dromey, B.), č. článku P2.181. Europhysics Conference Abstracts (ECA). ISBN 979-10-96389-07.
[EPS 2017 Conference on Plasma Physics/44./. Belfast (IE), 26.06.2017-30.06.2017]
Grant CEP: GA ČR(CZ) GA16-25074S; GA ČR(CZ) GA15-10723S; GA MŠMT(CZ) 8D15001; GA MŠMT(CZ) LM2015045
Institucionální podpora: RVO:61389021
Klíčová slova: COMPASS * Reynolds stress (RS) * Langmuir probes
Obor OECD: Fluids and plasma physics (including surface physics)

The Reynolds stress force ¶rh˜ vp ˜ vri due to the Reynolds stress (RS) h˜ vp ˜ vri has been identified in recent models and experiments [1] as a likely driver of poloidal zonal flows which are expected to play a key role in the L-H transition and the associated limit cycle oscillations (LCO) [2] in the predator-prey-like interaction of zonal flows with turbulence.
One common method of measuring the RS is to measure fluctuations of electric fields with arrays of Langmuir probes. However, such measurements may be influenced by the fluctuations of the electron temperature. Similar probe head arrangements have been also used to investigate the dynamics of density fluctuations and electric fields during LCO [2]. In order to investigate
the role of temperature fluctuations and LCO dynamics, two similar probe heads equipped with both Langmuir (LP) and ball-pen (BPP) [3] probes in similar geometric configurations were developed, installed and used at the COMPASS tokamak [4]. This contribution reports on the results of measurements with these probe heads, specifically on the comparison of RS profiles
obtained with BPP and LP and the investigation of limit cycle oscillations during the L-H transition on COMPASS.
Trvalý link: http://hdl.handle.net/11104/0278184