http://www.iop.org/EJ/article/-alert=34 ... a2a520a788
Large type-I edge localized modes (ELMs) are completely suppressed in hybrid discharges for the first time by applying an edge resonant perturbation (RMP) using an internal coil set with toroidal mode number n = 3. This is an important advance in developing hybrid discharges as a baseline operating scenario for ITER. In these experiments on the DIII-D tokamak, the ELM suppression lasts for ∼ 1 s in plasmas with normalized beta up to βN = 2.5 (volume average beta up to β = 3.4%) and a fusion performance factor as high as βNH98y2/q2 95 = 0.20, which equals the value for the Q = 10 scenario in ITER. A strong interaction between the 3/2 neoclassical tearing mode and the RMP, which slows the pedestal toroidal rotation, limits the achievable βN and the duration of ELM suppression.
They apply audio frequency currents (2 to 20 KHz) to auxiliary coils in the tokamak. The suppression only lasts for a few seconds. It appears to mode lock the plasma for a while.
Compare this with the Polywell where oscillations are encouraged at the plasma natural frequency and may be enhanced by POPS.
Fight with nature? Or work with it?