Optimization of Lower Hybrid Current Drive Efficiency for EAST Plasma with Non-Circular Cross Section and Finite Aspect-Ratio

摘要

The two-dimensional equilibrium with flexible boundaries is solved via using a MATLAB Equilibrium Code(MEC),which has applied the finite element method to handle the changeable plasma shape and employed the trust-region dogleg method to solve the nonlinear partial differential equation.The corresponding driven current profile is also calculated by coupling with the lower-hybrid simulation code(LSC).The results are applied to optimize the lower hybrid current drive(LHCD) efficiency for the Experimental Advanced Superconductor Tokamak(EAST) and suggested that both elongation and triangularity have a notable effect on the efficiency because of the competition between the increase in the resonant area and in the Shafranov shift.Moreover,large aspect-ratio has a negative effect on the efficiency.These effects are studied numerically,which might be considered carefully for both good plasma confinement and high LHCD efficiency.