Stabilizing Effect of Resistivity towards ELM-free H-mode Discharge in Lithium-conditioned NSTX
ORAL
Abstract
The stabilizing effect of edge resistivity on the edge localized modes (ELMs) has been recently recovered through analyzing NSTX experimental profiles of Lithium-conditioned ELM-free H-mode discharge. Comparative studies of ELM-free and a reference NSTX ELMy-H mode equilibriums have been performed using both resistive and 2-fluid MHD models implemented in the initial value extended MHD code NIMROD. Our results indicate that in addition to the pedestal profile refinement in electron pressure, the inclusion of enhanced resistivity due to the increase in the effective electric charge number $Z_{eff}$, which is observed after Lithium-conditioning in experiment, is further required to account for the full stabilization of the low-$n$ edge localized modes. Such a stabilization from the enhanced edge resistivity only becomes effective when the two-fluid diamagnetic and finite-Larmor-radius (FLR) effects are considered in the MHD model.
*Supported by the National Magnetic Confinement Fusion Program of China under grant Nos. 2014GB124002 and 2015GB101004, the 100 Talent Program and the President International Fellowship Initiative of the Chinese Academy of Sciences.
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