Plasma response to resonant magnetic perturbations in HL-3: roles of plasma shape and pressure

Plasma response to the resonant magnetic perturbations (RMPs), envisaged for controlling the edge-localized mode (ELM) in the HL-3 tokamak under high-pressure conditions, is investigated employing the MARS-F Liu Y Q et al 2000 Phys. Plasmas 7 3681 and MARS-K Liu Y Q et al 2008 Phys. Plasmas 15 112503 codes. Exploited mainly are influences of the plasma shape (upper and lower single-null, double-null and limiter shapes) and equilibrium pressure on the plasma response, following both the fluid and kinetic models of the plasma. Key physics quantities associated with the plasma response are examined, revealing that high equilibrium pressure drives significant amplification of the n = 1 (n is the toroidal mode number) RMP field in the plasma edge region. The single-null plasma configurations accommodate more effective ELM control, reducing the required equilibrium pressure for triggering a strong resonant field amplification effect. As a result, a stronger edge-peeling type of the plasma response is identified with the single-null shape. For the double-null configuration, the slight up-down asymmetric pattern of the perturbed magnetic field originates from the toroidal plasma flow. The plasma response computed with the kinetic model is similar to that with the fluid model, independent of the plasma shaping. Similar but less pronounced response effects are found for the n = 2 RMP.