Interpretive JOREK simulation of thermal quench triggered by massive gas injection in EAST disruptions

This is the authors' abstract. We don't add key points for this paper.

JOREK 3D non-linear magnetohydrodynamic simulations with non-equilibrium impurity treatment of thermal quench (TQ) triggered by a massive neon gas in EAST L-mode disruptions are first presented. Neon impurities are deposited at ΨN ∼ 0.7, followed by asymmetrical parallel extension along magnetic lines driven by a parallel self-consistent electrical field induced by plasma cooling process. Both double-stage and single-stage TQ observed in EAST experiments are reproduced through simulations with varying impurity particle fluxes. In double-stage TQ, non-linear interactions among the m/n = 3/1, 4/1, and 5/1 modes primarily contribute to edge stochastic. Growth of m/n = 2/1 mode initiates core energy loss during the first temperature collapse. Subsequently, the m/n = 2/1 mode of comparable large amplitude, along with higher harmonics, couples with the 3/1 mode, resulting in a global stochastic and total energy loss in the second collapse. The transition between double-stage and single-stage TQ is primarily determined by the n = 1 mode growth rate. In our simulations, the longer duration of double-stage TQ offers benefits for reducing the peak power of outward energy flux. Additionally, deeper impurity injection enhances radiative power and reduces outward energy flow. Strike point splitting on the upper-outer target, observed experimentally, is also reproduced in the simulations.