Rippling modes in the edge of a tokamak plasma

Technical Report · Mon Feb 01 04:00:00 EST 1982

DOI:https://doi.org/10.2172/5155019· OSTI ID:5155019

Carreras, B. A.; Callen, J. D.; Gaffney, P. W.; Hicks, H. R.

A promising resistive magnetohydrodynamic candidate for the underlying cause of turbulence in the edge of a tokamak plasma is the rippling instability. In this paper we develop a computational model for these modes in the cylindrical tokamak approximation and explore the linear growth and single-helicity quasi-linear saturation phases of the rippling modes for parameters appropriate to the edge of a tokamak plasma. Large parallel heat conduction does not stabilize these modes; it only reduces their growth rate by a factor scaling as k/sub parallel//sup -4/3/. Nonlinearly, individual rippling modes are found to saturate by quasi-linear flattening of the resistivity profile. The saturated amplitude of the modes scales as m/sup -1/, and the radial extent of these modes grows linearly with time due to radial Vector E x Vector B/sub 0/ convection. This evolution is found to be terminated by parallel heat conduction.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5155019
• Report Number(s): ORNL/TM-7989; ON: DE82007724
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
700202 -- Fusion Power Plant Technology-- Magnet Coils & Fields
CLOSED PLASMA DEVICES
ENERGY TRANSFER
HEAT TRANSFER
INSTABILITY GROWTH RATES
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELD RIPPLES
PLASMA SHEATH
QUASILINEAR PROBLEMS
SCALING LAWS
THERMAL CONDUCTION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TURBULENCE