LAUSR

Non-linear interaction between the edge localized infernal mode (ELIM) and the plasma toroidal flow is numerically investigated, by solving the initial value problem for the n = 1 ELIM, where n is the toroidal mode number. The linear results show that the ELIM instability is strongly affected by a close-fitting resistive wall. The presence of a resistive wall can fully stabilize an otherwise flow-shear destabilized ELIM. The computed toroidal torques based on linear ELIM eigenfunctions show different radial distributions: neoclassical toroidal viscous torque has a global distribution, whilst the torques associated with the Maxwell and Reynolds stresses largely peak near rational surfaces. The non-linear interplay between the unstable ELIM and the plasma flow tends to push the mode towards a more stable domain, no matter where the instability starts. This may help to understand some of the underlying physics for the experimentally observed edge harmonic oscillations in tokamak H-mode plasmas.