2025 – Compatibility of RMP ELM suppression with core pellet injection

Compatibility of RMP ELM suppression with core pellet injection

2025 Research Campaign, Pedestal and Non/Small ELM Regimes

Purpose of Experiment

The goal of this expeirment is to understand the compatibility of core pellet fueling with the technique of suppressing edge-localized modes (ELMs) by the application of resonant magnetic perturbations (RMPs). Because increasing the plasma density can result in loss of the plasma response necessary for keeping the plasma edge region below the ELM instability threshold, achieving both simultaneously poses a challenge. This is a critical issue for burning plasmas, where both ELM control and core fueling are essential requirements.

Experimental Approach

This experiment will exploit new DIII-D capabilities to adjust the size of fueling pellets and to quantitatively measure the resulting particle throughput, to provide detailed chracterization of the conditions under which pellet fueling results in the loss of ELM suppression. Detailed profile measurements in the edge “pedestal” region from this experiment will be utilized in magnetohydrodynamic modeling of the pedestal plasma response to understand the transition from suppression to ELMing, and to understand the resulting limits to core fueling via pellet injection.

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