Observation of Secondary Instability of 2/1 Magnetic Island in COMPASS High Density Limit Plasmas.

0483193 - ÚFP 2018 RIV FR eng C - Conference Paper (international conference)
Shah, S.I.W. - Salzedas, F. - Havlíček, Josef - Stöckel, Jan - Silva, C.
Observation of Secondary Instability of 2/1 Magnetic Island in COMPASS High Density Limit Plasmas.
EPS 2016: 43rd European Physical Society Conference on Plasma Physics. Vol. 40A. Mulhouse: European Physical Society, 2016 - (Mantica, P.; Giruzzi, G.; Fajardo, M.; Gans, T.; Poedts, S.; Vennekens, N.), č. článku P5.003. Europhysics Conference Abstracts (ECA), ECA, 40A. ISBN 2-914771-99-1.
[EPS 2016: Conference on Plasma Physics/43./. Leuven (BE), 04.07.2016-08.07.2016]
R&D Projects: GA MŠMT(CZ) LM2015045
Institutional support: RVO:61389021
Keywords : COMPASS * tokamak * density limit disruptions * secondary instability
OECD category: Fluids and plasma physics (including surface physics)

Density limit disruptions (DLDs) have been observed in high density tokamak plasmas. It is important to understand the dynamics of the DLDs so that better mitigation strategies can be developed. In this work, following detection in JET of a secondary instability (SI) to the m/n = 2/1 MHD mode in the precursor of DLD, we analyse the evolution of the magnetic island in COMPASS DLD to look for the presence of this SI just close to the onset of energy quench phase of the disruption. The presence of this SI was associated with the occurrence of minor disruptions preceding the major disruption and with the major disruption itself in [Salzedas, F., 2011]. The coherence observed between the perturbations caused by the SI in the magnetic poloidal flux and in the electron temperature was high, allowing to determine that the SI perturbations came from the same position as the magnetic island. In the work presented here, only the perturbations in the magnetic poloidal flux are analysed.
Permanent Link: http://hdl.handle.net/11104/0278786