Limit cycle oscillations measurements with Langmuir and ball-pen probes on COMPASS

0495216 - ÚFP 2019 RIV AT eng J - Článek v odborném periodiku
Grover, Ondřej - Seidl, Jakub - Refy, D. - Adámek, Jiří - Vondráček, Petr - Tomeš, Matěj - Junek, Pavel - Háček, Pavel - Krbec, Jaroslav - Weinzettl, Vladimír - Hron, Martin - Zoletnik, S.
Limit cycle oscillations measurements with Langmuir and ball-pen probes on COMPASS.
Nuclear Fusion. Roč. 58, č. 11 (2018), č. článku 112010. ISSN 0029-5515. E-ISSN 1741-4326.
[16th International Workshop on H-mode Physics and Transport Barriers. Petrohrad, 13.09.2017-13.09.2017]
Grant CEP: GA ČR(CZ) GA16-25074S
Institucionální podpora: RVO:61389021
Klíčová slova: confinement * generation * transport * plasma * flows * magnetic confinement * tokamak * L-H transition * limit-cycle oscillations * edge-localized modes
Obor OECD: Fluids and plasma physics (including surface physics)
Impakt faktor: 3.516, rok: 2018
http://iopscience.iop.org/article/10.1088/1741-4326/aabb19/meta

This contribution presents the experimentally observed edge plasma evolution during limit cycle oscillations (LCO) measured with a new Langmuir and ball-pen multi-pin probe head at the COMPASS tokamak. The observed LCO regime modulates the intensity of density fluctuations delta n(e), radial electric field E-r and intensity of D-alpha emission with a frequency 3-5 kHz. The density fluctuations grow after E-r decreases in strength which appears to be strongly correlated with the evolution of the pressure gradient partial derivative(r)p. The magnetic signature of the LCO shows a left-right asymmetry with propagation from the low to high field side. High-frequency (above 100 kHz) precursor-like oscillations are observed as well.
Trvalý link: http://hdl.handle.net/11104/0288230