Toroidal Momentum Confinement in Tokamaks
نویسندگان
چکیده
Theories for the toroidal momentum confinement in tokamaks have been developed. It is shown that the logarithmic gradient of the toroidal flow is a linear combination of logarithmic gradients of the plasma pressure and the temperature in neoclassical quasilinear theory. The fluctuation-induced toroidal stress consists of a diffusion flux, a convective flux, and a residual flux. The effects of a variety of magneto-hydrodynamic (MHD) activity, such as magnetic islands, and un stable MHD modes, on toroidal plasma rotation are also addressed. The key mechanism for the toroidal flow damping is the broken toroidal symmetry in |B | that results from MHD activities. Here, B is the magnetic field. The symmetry -breaking-induced toroidal viscosity also provides a mechanism to determine the island rotation frequency.
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