Studies of Global Stability of Fluid-reversed Configuration Plasmas using a Rigid Body Model

Technical Report · Wed Apr 01 04:00:00 EST 1998

DOI:https://doi.org/10.2172/16753· OSTI ID:16753

= H Ji, First Author ^[1]; Yamada, M ^[2]; Kulsrud, R ^[2]; Pomphrey, N ^[2]

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1. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ 08543 (US)
2. PPPL

Global stability of field-reversed configuration (FRC) plasmas has been studied using a simple rigid body model in the parameter space ofs (ratio of separatrix radius to average ion gyroradius) and plasma elongation E (ratio of separatrix length to separatrix diameter). Tilt stability is predicted, independent of s, for FRC`s with low E(oblate), while the tilt stability of FRC`s with large E (prolate)depends on s/E. It is found that plasma rotation due to ion diamagnetic drift can stabilize the tilt mode when s/E is less than or equal to1.7. The so-called collisionless ion gyroviscosity also is identified to stabilize tilt when s/E is less than or equal to 2.2. Combining these two effects, the stability regime broadens to s/E is less than or equal to 2.8, consistent with previously developed theories. A small additional rotation (e.g., a Mach number of 0.2) can improve tilt stability significantly at large E. A similar approach is taken to study the physics of the shift stability. It is found that radial shift is unstable when E is < 1 WHILE AXIAL SHIFT IS UNSTABLE WHEN E is> 1. However, unlike tilt stability, gyroviscosity has little effect onshift stability.

• Research Organization: Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (US)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (US)
• OSTI ID: 16753
• Report Number(s): PPPL--3296; ON: DE98058043
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CONFIGURATION
ELONGATION
MACH NUMBER
PHYSICS
PLASMA
ROTATION
STABILITY