Exploring Robustness of Magnetic Feedback Stabilization On Current-Driven Resistive Wall Mode Stabilization

The highly-reproducible current-driven resistive wall mode (RWM) was explored to assess the RWM physics and magnetic feedback capability. Application of feedback with sufficiently-high gain can robustly stabilize the q 95 ~ 4 current-driven RWM. Feedback stabilization needs a response time of ~1 ms, faster than the mode growth time of 3-4 ms. We have identified the feedback stabilization process as direct feedback rather than error field correction.