Theory of hot particle stability

Technical Report · Wed Oct 01 04:00:00 EDT 1986

OSTI ID:7082603

Berk, H L; Wong, H V; Tsang, K T

The investigation of stabilization of hot particle drift reversed systems to low frequency modes has been extended to arbitrary hot beta, ..beta../sub H/ for systems that have unfavorable field line curvature. We consider steep profile equilibria where the thickness of the pressure drop, ..delta.., is less than plasma radius, r/sub p/. The analysis describes layer modes which have m..delta../r/sub p/ < 1, where m is the mode number, and radial structure larger than ..delta... We show that in making a continuous transition from the fragile stability regime to the robust stability regime one must go through an unstable region. To bridge the unstable band in a physical manner one must either produce robust stability conditions very rapidly, or use transient stability techniques such as ponderomotive forces or transient minimum-B coils. We explicitly exhibit the positive energy stabilization terms of the layer mode from wall stabilization terms and finite Larmor radius terms. It is shown the robust stability can even be achieved with only wall stabilization, for all possible m-values of the layer modes if ..beta../sub H/ > 2/3. When robust stability conditions are fulfilled, the hot particles will have their axial bounce frequency less than their grad-B drift frequency. This allows for a low bounce frequency expansion to describe the axial dependence of the magnetic compressional response.

• Research Organization: Texas Univ., Austin (USA). Inst. for Fusion Studies; Science Applications International Corp., Boulder, CO (USA)
• DOE Contract Number: FG05-80ET53088
• OSTI ID: 7082603
• Report Number(s): DOE/ET/53088-235; IFSR-235; ON: DE87001933
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ANALYTICAL SOLUTION
HIGH-BETA PLASMA
INSTABILITY
LARMOR RADIUS
MATHEMATICAL MODELS
PLASMA
PLASMA DRIFT
PLASMA INSTABILITY
STABILIZATION