Calculations of axisymmetric stability of tokamak plasmas with active and passive feedback

Technical Report · Mon Jul 01 00:00:00 EDT 1991

DOI:https://doi.org/10.2172/5510938· OSTI ID:5510938

Ward, D J; Jardin, S C; Cheng, C Z

A new linear MHD stability code, NOVA-W, has been developed in order to study feedback stabilization of the axisymmetric mode in deformable tokamak plasmas. The NOVA-W code is a modification of the non-variational MHD stability code NOVA that includes the effects of resistive passive conductors and active feedback circuits. The vacuum calculation has been reformulated in terms of the perturbed poloidal flux to allow the inclusion of perturbed toroidal currents outside the plasma. The boundary condition at the plasma-vacuum interface relates the instability displacement to the perturbed poloidal flux. This allows a solution of the linear MHD stability equations with the feedback effects included. The passive stability predictions of the code have been tested both against a simplified analytic model and against a different numerical calculation for a realistic tokamak configuration. The comparisons demonstrate the accuracy of the NOVA-W results. Active feedback calculations are performed for the CIT tokamak design demonstrating the effect of varying the position of the flux loops that provide the measurements of vertical displacement. The results compare well with those computed earlier using a less efficient nonlinear code. 37 refs., 13 figs.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 5510938
• Report Number(s): PPPL-2776; ON: DE91016216; TRN: 91-022214
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TOKAMAK DEVICES
FEEDBACK
MHD EQUILIBRIUM
AXIAL SYMMETRY
BOUNDARY CONDITIONS
FIELD EQUATIONS
GREEN FUNCTION
MAGNETIC FIELDS
PLASMA INSTABILITY
CLOSED PLASMA DEVICES
EQUATIONS
EQUILIBRIUM
FUNCTIONS
INSTABILITY
SYMMETRY
THERMONUCLEAR DEVICES
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