A brief review on the interaction between resonant magnetic perturbation and tearing mode in J‑TEXT

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First Author:Nengchao Wang

Correspondence Author:Yonghua Ding

Journal:Reviews of Modern Plasma Physics

Volume:6

Page Number:26

DOI number:10.1007/s41614-022-00090-4

Date of Publication:2022-09-07

Abstract:The J-TEXT tokamak is featured with experimental researches with the application of the resonant magnetic perturbation (RMP) field. The interaction between RMP and the tearing mode (TM) has been studied extensively on J-TEXT during the past decade. The RMP systems consist of two sets of RMP coils installed either outside the vacuum vessel (VV) or inside VV, which is very flexible for the experiments. The RMP can be rotated at a few kilohertz, leading to either acceleration or deceleration of the TM velocity and the plasma rotation. The torque inserted by a rotating RMP to a TM can be used to unlock a locked mode or to avoid the rotating TM being locked to the error field (EF), hence preventing major disruptions. The static RMP with proper amplitude can also extend the plasma operational parameter toward higher density and lower edge safety factor. The EF is measured with a compass scan, and its impact on the low frequency rotating TM is studied. Non-uniform rotation of a TM with a period of 1 kHz has been observed, and the TM rotation recovers to a uniform rotation with the proper EF correction. The RMP penetration is observed together with the excitation of a born locked mode for poloidal/toroidal mode number m/n = 2/1, 3/1 or 2/2. The penetration threshold is found to vary non-monotonically on electron density.

Links to published journals:https://doi.org/10.1007/s41614-022-00090-4