research

On the magnetic nature of electron transport barriers in tokamaks

Abstract

The formation of internal transport barriers in the vicinity of rational magnetic surfaces in tokamaks with braided magnetic fields is studied for a simplified model of the perturbed magnetic field with a broad spatial spectrum and a monotonous shear profile. The island overlap criterion is used to derive a condition for barrier formation. This condition links the amplitude and the spectral width of the perturbation with the shear parameter. Numerical experiments with the MHD Monte-Carlo code E3D, where the problem of plasma heat conductivity is solved in 3D, confirm this formation of transport barriers in the case of a monotonous shear profile. Assuming that experimentally observed electron internal transport barriers are the result of local reduction of electron heat transport due to the magnetic field braiding, the amplitude and spectral width of magnetic perturbations are estimated for the tokamak RTP

    Similar works