Nonlinear growth of marginally unstable tearing modes

Journal Article · Tue May 15 04:00:00 EDT 2007 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2722306· OSTI ID:20974972

Coelho, R ^[1]

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1. Associacao Euratom/IST, Centro de Fusao Nuclear, 1049-001 Lisbon (Portugal)

In this work, the nonlinear growth of the classical tearing mode is revisited, using reduced magnetohydrodynamic numerical simulations in cylindrical geometry, emphasizing the limiting scenario of a marginally unstable mode, i.e., 0{approx}{delta}{sup '}a<4, where a is the minor radius and {delta}{sup '} is the stability parameter [H. Furth, J. Killeen, and M. N. Rosenbluth, Phys. Fluids 6, 459 (1963)]. Conventionally, the mode becomes unstable when {delta}{sup '}>0 and, eventually, a steady state island width (saturated island width) is achieved. It is found that, contrary to theoretical predictions, no steady state solution is obtained for typically low temperature plasmas with perpendicular viscosity and magnetic Reynolds number below a certain threshold. Plasma inertial forces are identified as the physical mechanism behind such nonlinear evolution.

• OSTI ID: 20974972
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 14; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CYLINDRICAL CONFIGURATION
ELECTRON TEMPERATURE
ION TEMPERATURE
MAGNETIC REYNOLDS NUMBER
MAGNETOHYDRODYNAMICS
MATHEMATICAL SOLUTIONS
NONLINEAR PROBLEMS
PLASMA
PLASMA SIMULATION
STEADY-STATE CONDITIONS
TEARING INSTABILITY