Extended MHD simulation of resonant magnetic perturbations

다국어 초록 (Multilingual Abstract)

<P>Resonant magnetic perturbations (RMPs) have been found effective in suppressing edge localized modes (ELMs) in the DIII-D experiment (Evans <I>et al</I> 2006 <I>Phys. Plasmas</I> <B>13</B> 056121, Moyer <I>et al</I> 2005 <I>Phys. Plasmas</I> <B>12</B> 056119). Simulations with the M3D initial value code indicate that plasma rotation, due to an MHD toroidal rotation or to two-fluid drifts, has an essential effect on the RMP. When the flow is below a threshold, the RMP field can couple to a resistive mode with a helical structure, different from the usual ELM, that amplifies the non-axisymmetric field. The magnetic field becomes stochastic in the outer part of the plasma, causing density and temperature loss. At higher rotation speed, the resistive mode is stabilized and the applied RMP is screened from the plasma, so that the stochastic magnetic layer is thinner and the temperature remains similar to the initial unperturbed state. The rotational flow effects, along with the remnants of the screened RMP, cause a density loss which extends into the plasma core. The two-fluid model contains intrinsic drift motion and axisymmetric toroidal rotation may not be needed to screen the RMP nor stabilize the resistive mode.</P>