Abstract Details
Abstracts
Author: Chang Liu
Requested Type: Consider for Invited
Submitted: 2023-03-24 16:22:04
Co-authors: Andrey Lvovskiy, Carlos Paz-Soldan, Stephen C. Jardin, Amitava Bhattacharjee
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator Rd
PRINCETON, NJ 08540
US
Abstract Text:
Alfvénic modes in the current quench (CQ) stage of the tokamak disruption have been observed in experiments. In DIII-D the excitation of these modes is associated with the presence of high-energy runaway electrons, and a strong mode excitation is often associated with the failure of RE plateau formation. In this work we present the first result of self-consistent kinetic-MHD simulations of RE-driven compressional Alfvén eigenmodes (CAEs) in DIII-D disruption scenarios, providing an explanation of the CQ modes. Simulation results reveal that high energy trapped REs can have resonance with the Alfvén mode through their precession motion, and the resonance frequency is proportional to the energy of REs. The mode frequencies and their relationship with the RE energy are consistent with experimental observation. The perturbed magnetic fields from the modes can lead to spatial diffusion of runaway electrons including the nonresonant passing ones, thus providing the theoretical basis for a potential approach for runaway electron mitigation.
1. C. Liu, A. Lvovskiy, C. Paz-Soldan, S.C. Jardin, and A. Bhattacharjee, arXiv:2303.03622 (2023)
2. C. Liu, D.P. Brennan, A. Lvovskiy, C. Paz-Soldan, E.D. Fredrickson, and A. Bhattacharjee, Nucl. Fusion 61(3), 036011 (2021).
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