Destabilization of the trapped-electron mode by magnetic curvature drift resonances

Journal Article · Thu Apr 01 04:00:00 EST 1976 · Physics of Fluids (New York)

DOI:https://doi.org/10.1063/1.861489· OSTI ID:4079149

Adam, J. C.; Tang, W. M.; Rutherford, P. H.

Electron curvature drift resonances, ignored in earlier work on the trapped-electron modes, are found to exert a strong destabilizing influence in the lower collision frequency range of these instabilities. Effects arising from ion temperature gradients, shear, and finite ion gyroradius are included with these ∇B drifts in the analysis, and the resultant eigenvalue equation is solved by numerical procedures rather than the commonly used perturbation techniques. For typical tokamak parameters the maximum growth rates are found to be increased over earlier estimates by roughly a factor of 4, and requirements on magnetic shear strength for stabilization are likewise more severe and very difficult to satisfy. For inverted density profiles, this new destabilizing effect is rendered ineffective, with the result that the modes can be stabilized for achievable values. of shear provided the temperature gradients are not too severe. Finally, estimates of the particle and thermal energy transport are given for both normal and inverted profiles.

• Research Organization: Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08540
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-028745
• OSTI ID: 4079149
• Journal Information: Physics of Fluids (New York), Journal Name: Physics of Fluids (New York) Journal Issue: 4 Vol. 19; ISSN 0031-9171; ISSN PFLDAS
• Publisher: American Institute of Physics
• Country of Publication: United States
• Language: English

Related Subjects

*PLASMA MACROINSTABILITIES-- TRAPPED-PARTICLE INSTABILITY
700107* --Fusion Energy--Plasma Research--Plasma Instabilities
COLLISIONS
ELECTRONS
LARMOR RADIUS
MAGNETIC FIELDS
N70700* --Physics--Controlled Thermonuclear Research-- Stability
PLASMA INSTABILITY
TRAPPING