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Experiments on Experimental Advanced Superconducting Tokamak (EAST) were performed with high normalized beta () and favorable energy confinement () for the operating space achieved in EAST. Gyrokinetic simulations were carried out for four different cases with the experimental plasma parameters and tokamak equilibrium data. It was found that the favorable confinement is effectively maintained when increases to 1.9. The radial distribution of potential fluctuation during turbulence saturation phase is consistent with that of thermal transport diffusivity. Turbulence with higher toroidal modes becomes important as increases, and zonal flow shearing rate suppresses the turbulence when increases to 1.9, which is responsible for the well-maintained confinement. [ABSTRACT FROM AUTHOR]

The fast-ion transport during neutral beam injection on the Experimental Advanced Superconducting Tokamak (EAST) is studied. Based on the NUBEAM and TRANSP codes, it is found that fast-ion transport is anomalous when the minimum safety factor (qmin) is about 2, while it is neoclassical when qmin is around 1. Neutral beam injection heating efficiency, plasma stored energy, and the total heating power are reduced when the fast ion transport is anomalous. The Alfvén continuum spectrum and the mode structures of toroidal Alfvén eigenmodes (AEs) are also calculated for comparison between neoclassical fast-ion transport and anomalous fast-ion transport. High-qmin discharge with anomalous fast-ion transport has more AE activity than that of lower qmin discharge with neoclassical fast-ion transport. [ABSTRACT FROM AUTHOR]

In the present RF-driven plasma with a lot of high-energy electrons, there may be anisotropic plasma pressure, which makes the usual equilibrium analysis difficult, but the Cauchy condition surface method can reconstruct the plasma shape precisely regardless of the anisotropy. In addition, the plasma current effect in the open magnetic surfaces outside of the closed magnetic surfaces is considered in the RF-driven divertor plasma. In the reconstruction process, singular value (SV) decomposition is used and optimal criterion function for generalized cross validation is estimated concerning truncation or reduction of the small-SV components. [ABSTRACT FROM PUBLISHER]