Nonlinear theory of drift and trapped particle instabilities

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5139719

Kim, S Y

A theory of broad band turbulent spectrum of drift-wave type instabilities in a sheared magnetic field was developed. It is shown that different nonlinear processes are dominant in different k regimes: nonlinear shear dampling, ion scattering of beat waves, and the Hasegawa-Mima solution. Significant energy sink in the nonlinear shear damping ensures true steady state turbulent solutions. A new theory of nonlinear saturation of a single mode trapped particle instability was developed. The general theory was applied to a trapped electron mode and a dissipative trapped ion mode, which obey different nonlinear equations. The key features of the new theory are the proper two dimensional treatment of the linear eigenvalue problem and appropriate recognition of the intrinsic two dimensional nature of E vector x B vector and polarization drift nonlinearities. Mode coupling to the damped high order radial harmonic is the principal physical saturation mechanism of the unstable fundamental radial harmonic. In the same spirit, the nonlinear saturation level of a single mode collisionless trapped particle instability is also calculated.

• Research Organization: Columbia Univ., New York (USA)
• OSTI ID: 5139719
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
DRIFT INSTABILITY
INSTABILITY
NONLINEAR PROBLEMS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA MICROINSTABILITIES
SHEAR
TRAPPED-PARTICLE INSTABILITY
TURBULENCE
TWO-DIMENSIONAL CALCULATIONS