https://doi.org/10.1140/epjd/e20020060
Generic structure of externally driven tearing modes instabilities
1
Istituto di Fisica del Plasma “P.Caldirola", Consiglio Nazionale delle Ricerche,
Euratom-ENEA-CNR Association, Via R. Cozzi 53, 20125 Milan, Italy
2
Associação EURATOM/IST, Centro de Fusão Nuclear, 1096 Lisbon Codex, Portugal
Corresponding author: a lazzaro@ifp.mi.cnr.it
Received:
12
November
2001
Revised:
4
January
2002
Published online: 15 April 2002
A major limit to steady state and advanced high 
operation of tokamaks of reactor class is due to the onset of tearing modes that develop magnetic and may cause loss of energy confinement or a major disruption. Here the structure of a classical problem about the effects of external control helical fields is analysed and it is shown to offer a general paradigm of response of low order classical and neoclassical tearing modes to a wide class of external perturbations. New results of principle on the structural stability of the response model are obtained, leading to a clear interpretation of the role of “seed islands" in the onset of neo-classical tearing modes and the role of finite ion larmor radius corrections to Ohm's law.
PACS: 52.35.Py – Macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, Rayleigh-Taylor, etc.) / 52.25.Fi – Transport properties / 52.35.Mw – Nonlinear phenomena: waves, wave propagation, and other interactions (including parametric effects, mode coupling, ponderomotive effects, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002
