Early Plasma Stability and Temperature Prediction from Total VUV Emission

This repository provides the paper, analysis code, and visualization tools associated with the study: “Early Plasma Stability and Temperature Prediction from Total VUV Emission — 20-Year Validation Using LHD Experimental Data —” This work investigates whether the total vacuum ultraviolet (VUV) emission can be used as an early structural indicator for plasma stability and temperature evolution in long-duration fusion experiments. Using approximately 20 years of experimental data from the Large Helical Device (LHD), we derive two independent indicators from total VUV emission: - Structural Stability Index (Sc) - Temperature-related Indicator (Te) These indicators are not obtained by direct temperature fitting, but by evaluating structural redistribution inferred from the evolution of VUV intensity. Long-term averaged validation shows the following agreement ranges: - Structural stability: 95–99% - Temperature indicator: 85–95% - Predictive accuracy: 80–95% Reduced agreement is mainly observed during impurity injection or accumulation phases. Importantly, the VUV-based method detects structural deviations earlier than conventional diagnostics, enabling fast alert generation. This repository includes: - The full research paper - Sample datasets - HTML-based interactive analysis and visualization tools All materials are provided to encourage independent verification and reuse for non-commercial research purposes. License: Creative Commons Attribution–NonCommercial 4.0 International (CC BY-NC 4.0) Author: Yuuki Theory (ORCID: 0009-0003-5736-5297)