Ideal low-n and Mercier mode stability boundaries for 1 = 2 torsatrons

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7246869

Dominguez, N; Leboeuf, J N; Carreras, B A; Lynch, V E

We have studied the relationship between the stability properties of ideal low-n internal modes and the 3-D ideal Mercier criterion for 1 = 2 torsatron configurations. For the low-n stability studies, the stellarator expansion has been used as implemented in the FAR code. The 3-D Mercier criterion has been applied to the equilibria calculated with the VMEC code. This investigation has been carried out for several torsatron configurations, exploring a broad range of aspect ratios, and different pressure profiles. We find that: 1) the low-n modes with singular surfaces lying in a Mercier region are in general unstable, and 2) the critical ..beta.. given by the Mercier criterion agrees well with the critical ..beta.. for the lowest n unstable mode. This is verified even in the case of global n = 1 modes. Therefore, the 3-D Mercier criterion is a useful guide in mapping the ideal stability ..beta.. limits for these torsatron configurations. 12 figs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7246869
• Report Number(s): CONF-8804103-2-Vugraphs; ON: DE88009872
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CLOSED PLASMA DEVICES
COMPUTER CODES
DATA
EQUILIBRIUM PLASMA
F CODES
INFORMATION
MATHEMATICS
MERCIER CRITERION
NUMERICAL ANALYSIS
NUMERICAL DATA
PLASMA
R CODES
STABILITY
STELLARATORS
THEORETICAL DATA
THERMONUCLEAR DEVICES
THREE-DIMENSIONAL CALCULATIONS
TORSATRON STELLARATOR
TWO-DIMENSIONAL CALCULATIONS
V CODES