Edge localized mode rotation and the nonlinear dynamics of filaments

0460362 - ÚFP 2017 RIV US eng J - Journal Article
Morales, J.A. - Bécoulet, M. - Garbet, X. - Orain, F. - Dif-Pradalier, G. - Hoelzl, M. - Pamela, S. - Huijsmans, G.T.A. - Cahyna, Pavel - Fil, A. - Nardon, E. - Passeron, C. - Latu, G.
Edge localized mode rotation and the nonlinear dynamics of filaments.
Physics of Plasmas. Roč. 23, č. 4 (2016), č. článku 042513. ISSN 1070-664X. E-ISSN 1089-7674
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : Edge Localized Modes (ELMs) * MHD * tokamak * ITER
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.115, year: 2016
http://scitation.aip.org/content/aip/journal/pop/23/4/10.1063/1.4947201

Edge Localized Modes (ELMs) rotating precursors were reported few milliseconds before an ELM crash in several tokamak experiments. Also, the reversal of the filaments rotation at the ELM crash is commonly observed. In this article, we present a mathematical model that reproduces the rotation of the ELM precursors as well as the reversal of the filaments rotation at the ELM crash. Linear ballooning theory is used to establish a formula estimating the rotation velocity of ELM precursors. The linear study together with nonlinear magnetohydrodynamic simulations give an explanation to the rotations observed experimentally. Unstable ballooning modes, localized at the pedestal, grow and rotate in the electron diamagnetic direction in the laboratory reference frame. Approaching the ELM crash, this rotation decreases corresponding to the moment when the magnetic reconnection occurs. During the highly nonlinear ELM crash, the ELM filaments are cut from the main plasma due to the strong sheared mean flow that is nonlinearly generated via the Maxwell stress tensor.
Permanent Link: http://hdl.handle.net/11104/0260459