Non-linear dynamics of compound sawteeth in tokamaks

Journal Article · Sun May 15 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4949342· OSTI ID:22600189

Garbet, X.; Sabot, R.; Guirlet, R.; Février, O.; Maget, P. ^[1]; Lütjens, H.; Marx, A.; Luciani, J. -F. ^[2]; Nicolas, T. ^[3]

---

1. CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)
2. Centre de Physique Théorique, Ecole Polytechnique, CNRS, F-91128 Palaiseau (France)
3. National Institute for Fusion Science, 332-6 Oroshi-cho, Toki 509-5292 (Japan)

Compound sawteeth is studied with the XTOR-2F code. Non-linear full 3D magnetohydrodynamic simulations show that the plasma hot core is radially displaced and rotates during the partial crash, but is not fully expelled out of the q = 1 surface. Partial crashes occur when the radius of the q = 1 surface exceeds a critical value, at fixed poloidal beta. This critical value depends on the plasma elongation. The partial crash time is larger than the collapse time of an ordinary sawtooth, likely due to a weaker diamagnetic stabilization. This suggests that partial crashes result from a competition between destabilizing effects such as the q = 1 radius and diamagnetic stabilization.

• OSTI ID: 22600189
• Journal Information: Physics of Plasmas, Vol. 23, Issue 5; Other Information: (c) 2016 Author(s); 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
ELONGATION
MAGNETOHYDRODYNAMICS
NONLINEAR PROBLEMS
PLASMA
PLASMA INSTABILITY
PLASMA SIMULATION
SAWTOOTH OSCILLATIONS
STABILIZATION
SURFACES
THREE-DIMENSIONAL CALCULATIONS
TOKAMAK DEVICES