Two and three dimensional tokamak equilibrium modifications driven by localized ICRF (ion cyclotron range of frequencies) ponderomotive force

Technical Report · Sat Aug 01 04:00:00 EDT 1987

OSTI ID:6200994

Myra, J R

Large ponderomotive forces can occur when ICRF waves are employed in stabilization or high power heating schemes. It is shown that the MHD equilibrium of the plasma is modified when the rf antenna is localized poloidally and/or toroidally. In the 2D problem (toroidally uniform rf) a modified Grad-Shafranov equation describes ponderomotively driven magnetic surface distortions. At electric fuel strengths of interest for ICRF stabilization, the equilibrium distortions are small provided that L/sub rf/ << a and the poloidal localization of the rf is not severe. The character of the 3D problem (toroidally and poloidally varying rf) depends on whether or not the ponderomotive force couples to rational surface within the plasma. For the case without rational surfaces, the 3D component of the distortions is found to be small by 1/q/sub a//sup 2/ relative to the 2D component. In the case where rational surfaces are excited, magnetic islands result. A threshold condition for island overlap determines the rf electric field at which ergodicity may be expected. It is shown that ergodicity of the edge plasma may occur for some cases of interest for heating and stabilization, but should be controllable.

• Research Organization: Science Applications International Corp., Boulder, CO (USA). Plasma Research Inst.
• DOE Contract Number: AC03-76ET53057
• OSTI ID: 6200994
• Report Number(s): SAIC-87/1089; PRI-113; ON: DE87014694
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
&amp; Production
700102 -- Fusion Energy-- Plasma Research-- Diagnostics
ANALYTICAL SOLUTION
CLOSED PLASMA DEVICES
DIFFERENTIAL EQUATIONS
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
EQUATIONS
EQUILIBRIUM
GRAD-SHAFRANOV EQUATION
HEATING
HIGH-BETA PLASMA
HIGH-FREQUENCY HEATING
ICR HEATING
INSTABILITY
LOW-BETA PLASMA
MAGNETIC FIELDS
MATHEMATICAL MODELS
MODIFICATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
PLASMA DIAGNOSTICS
PLASMA HEATING
PLASMA INSTABILITY
RADIATIONS
RADIOWAVE RADIATION
THERMONUCLEAR DEVICES
THREE-DIMENSIONAL CALCULATIONS
TOKAMAK DEVICES
TWO-DIMENSIONAL CALCULATIONS