BETA LIMITS IN RACETRACK SHAPED TOKAMAKS
The n = 1 free boundary kind mode imposes important limitations on both the current configuration and the attainable beta in tokamak plasmas. The n = O axisymmetric mode imposes further constraints on the current profile if the poloidal cross-section is elongated. Large n ballooning modes place further limits on the beta. All of these constraints become more severe with increasing elongation of the cross-section. The authors present the results of a study of the stability against axisymmetric (n=O), kink (n=1) and ballooning modes of elongated tokamak plasmas, characterized by a racetrack shaped poloidal cross- section, up to an elongation of 4 to 1. Current limitation studies are used to define operational windows for stability against current-driven kink modes at low beta. beta optimization studies are used to determine the beta limits imposed by the simultaneous requirements of stability to kink and ballooning modes, within the stable operating regime. Wall stabilization studies are presented to examine the feasibility of stabilization of axisymmetric modes by a nearby conducting wall.
Bibliographic Reference: 1986 SHERWOOD THEORY CONFERENCE, NEW YORK (USA), APRIL 14-16, 1986 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 32534 ORA
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Record Number: 1989125006200 / Last updated on: 1987-01-01
Available languages: en