Search

To design the alternating current operation of the J-text tokamak, this paper studies the plasma equilibrium during the plasma toroidal current reversing. First, four alternative current reversal equilibrium configurations with circular cross section when the total toroidal current becomes zero were constructed. Then, the profile of the plasma current was used as the input of a fixed boundary equilibrium solver to calculate the poloidal field coil currents. According to the results, the relationship between the plasma current distribution and currents in ohmic heating coils and vertical field coils is discussed. Finally, the plasma equlibrium of a toroidal current reversal with total plasma current from 40 kA to –40 kA in 40 ms was designed. [ABSTRACT FROM AUTHOR]

This paper studies the impact of Poloidal Field (PF) coil current disturbance on plasma shape in Experimental Advanced Superconductive Tokamak (EAST). First, the concept of the free-boundary equilibrium problem is studied. Based on the non-rigid plasma model, a free-boundary equilibrium solver developed in MATLAB software is presented to calculate the flux distribution and plasma profile of EAST plasma equilibrium, and the results are validated against the experiments. Second, given a typical double-null plasma equilibrium, the responses of plasma shape to the lower PF coil currents are computed using the orthogonal test method. The dependences of the elongation and triangularity of plasma shape on PF coil currents are obtained, showing that the currents in PF6 and PF8 have the greatest impact on triangularity and elongation for lower single-null (LSN) divertor configuration, respectively. And for double-null (DN) divertor plasma configuration, PF5 and PF7 play equally important roles due to the up-down symmetry. The conclusions will be useful for the design of EAST plasma shape feedback control. [ABSTRACT FROM AUTHOR]