Bessel function model of the electron pressure profile normalized by gyro-Bohm type parameter dependence

A model of electron pressure profile named gyro-Bohm normalized Bessel function model (GB-BFM) has been proposed. GB-BFM is composed of a profile term given by zero-order Bessel function, which is based on the diffusive transport in cylindrical plasmas, and gyro-Bohm type parameter dependences on the density profile, the total heating power, and the magnetic field strength. Using GB-BFM, one can figure out the region where the transport is gyro-Bohm like and diffusive. GB-BFM has been applied to the experiments in LHD. Profile analysis of the plasmas with or without a large magnetic island induced by resonant magnetic perturbation coils has revealed that the gyro-Bohm like diffusion is prevailing in the plasmas independent of the existence of island, except for the edge region. The gyro-Bohm like and diffusive transport property is also recognized in the mantle region of high-density plasmas with an internal diffusion barrier, while the superdense core region is improved compared with GB-BFM. (author)