Edge localized mode rotation and the nonlinear dynamics of filaments

Journal Article · Fri Apr 15 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4947201· OSTI ID:22599133

Morales, J. A.; Bécoulet, M.; Garbet, X.; Dif-Pradalier, G.; Huijsmans, G. T. A.; Fil, A.; Nardon, E.; Passeron, C.; Latu, G. ^[1]; Orain, F.; Hoelzl, M. ^[2]; Pamela, S. ^[3]; Cahyna, P. ^[4]

---

1. CEA, IRFM, 13108 St. Paul-Lez-Durance (France)
2. Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany)
3. CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)
4. Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 182 00 Prague 8 (Czech Republic)

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.

• OSTI ID: 22599133
• Journal Information: Physics of Plasmas, Vol. 23, Issue 4; Other Information: (c) 2016 EURATOM; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BALLOONING INSTABILITY
COMPUTERIZED SIMULATION
EDGE LOCALIZED MODES
ELECTRONS
FILAMENTS
HYDRODYNAMIC MODEL
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
NONLINEAR PROBLEMS
PLASMA
PRECURSOR
ROTATING PLASMA
SHEAR
TENSORS
TOKAMAK DEVICES
VELOCITY