The paper, titled “A Phenomenological Analytic Surrogate Model for Pedestal Entropy Production Rate as a Real-Time Scalar Precursor of Type-I ELM Crashes in Tokamaks”, presents a compact, fully analytic nonlinear surrogate S(τ) whose derivative dS/dτ serves as a lightweight, physics-based real-time scalar for detecting the nonlinear crash phase of Type-I ELMs. The model is calibrated directly to 2025 experimental heat-flux and pedestal data (Perillo et al., Lin et al., and KSTAR), uses the standard ideal-MHD entropy definition (Fitzpatrick Eq. 4.45), and is explicitly framed as phenomenological (no microscopic trigger or new physics is claimed). A figure and detailed validation table show order-of-magnitude agreement with the observed ELM cycle.
Sneh Vats (Fri,) studied this question.