Optimization and control of the plasma shape and current profile in noncircular cross-section tokamaks
High-..beta.. equilibria which are stable to all ideal MHD modes are found by optimizing the plasma shape and current profile for doublets, up-down asymmetric dees, and symmetric dees. The ideal MHD stability of these equilibria for low toroidal mode number n is analyzed with a global MHD stability code, GATO. The stability to high-n modes is analyzed with a localized ballooning code, BLOON. The attainment of high ..beta.. is facilitated by an automated optimization search on shape and current parameters. The equilibria are calculated with a free-boundary equilibrium code using coils appropriate for the Doublet III experimental device. The optimal equilibria are characterized by broad current profiles with values of ..beta../sub poloidal/ approx. =1. Experimental realization of the shapes and current profiles giving the highest ..beta.. limits is explored with a 1 1/2-D transport code, which simulates the time evolution of the 2-D MHD equilibrium while calculating consistent current profiles from a 1-D transport model. Transport simulations indicate that nearly optimal shapes may be obtained provided that the currents in the field-shaping coils are appropriately programmed and the plasma current profile is sufficiently broad. Obtaining broad current profiles is possible by current ramping, neutral beam heating, and electron cyclotron heating. With combinations of these techniques it is possible to approach the optimum ..beta.. predicted by the MHD theory.
- Research Organization:
- General Atomic Co., San Diego, CA (USA)
- DOE Contract Number:
- AT03-76ET51011
- OSTI ID:
- 5272053
- Report Number(s):
- GA-A-15899; IAEA-CN-38/J-5; CONF-800707-13; TRN: 80-013164
- Resource Relation:
- Conference: 8. international conference on plasma physics and controlled nuclear fusion research, Brussels, Belgium, 1 Jul 1980
- Country of Publication:
- United States
- Language:
- English
Similar Records
KSTAR Equilibrium Operating Space and Projected Stabilization at High Normalized Beta
Measurement and Modelling of Tearing Mode Stability for Steady-State Plasmas in DIII-D
Related Subjects
TOKAMAK DEVICES
OPTIMIZATION
ELECTRIC CURRENTS
HIGH-BETA PLASMA
MAGNETIC FIELD CONFIGURATIONS
PLASMA
PLASMA MACROINSTABILITIES
SHAPE
CLOSED PLASMA DEVICES
CONFIGURATION
CURRENTS
INSTABILITY
PLASMA INSTABILITY
THERMONUCLEAR DEVICES
700103* - Fusion Energy- Plasma Research- Kinetics