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Title: Neoclassical theory of momentum transport by collisional ions in strongly-rotating tokamak plasmas with unbalanced neutral-beam injection

Technical Report ·
OSTI ID:6311174

A neoclassical theory for momentum transport by collisional ions in a tokamak plasma with strong NBI and strong rotation is developed. A consistently ordered hierarchy of approximations to the kinetic equation are derived and solved to obtain expressions for particle flows, the radial electric field, poloidal asymmetries in density and potential, and the radial flux of toroidal angular momentum and the associated torque that acts to damp toroidal rotation. Upon decomposing the first-order distribution function into gyroangle-dependent and gyroangle-averaged components, neoclassical gyroviscosity is recovered from the former, and a new rotational viscosity of a collisional origin is recovered from the latter. The same viscosity coefficient and functional form is obtained for both types of viscosity. The magnitude and scaling with plasma parameters of the associated momentum damping rate has previously been demonstrated to be in agreement with a number of rotation experiments in tokamaks.

Research Organization:
Georgia Inst. of Tech., Atlanta, GA (USA). Fusion Research Center
OSTI ID:
6311174
Report Number(s):
PB-91-127290/XAB; GTFR-96; TRN: 91-004938
Country of Publication:
United States
Language:
English