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arXiv · 1607.07358

Stabilizing effects of resistivity on low-n edge localized modes in NSTX

Debabrata Banerjee·Ping Zhu·Rajesh Maingi
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Abstract

The stabilizing effects of enhanced edge resistivity on the low-n edge localized modes (ELMs) are reported for the first time in the context of ELM suppression in H-mode discharge due to Lithium-conditioning in the National Spherical Torus Experiment (NSTX). Here n is the toroidal mode number. Linear stability analysis of the corresponding experimental equilibrium suggests that the change in the equilibrium plasma density profile alone due to Lithium-conditioning may be insufficient for a complete suppression of ELMs. The enhanced resistivity due to the increased effective electric charge number Z eff after Lithium-conditioning can account for additional stabi- lization effect necessary for full ELM suppression. Remarkably, such a stabilizing effect of enhanced edge resistivity on the low-n ELMs only exists when two-fluid effects are considered in the MHD model.

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Debabrata Banerjee, Ping Zhu, Rajesh Maingi. 2016-07-25. Stabilizing effects of resistivity on low-n edge localized modes in NSTX. https://arxiv.org/abs/1607.07358

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