Developing an IMAS-compatible platform for the university-scale tokamak VEST and its application to operating characteristics analysis

Modern tokamak research is characterized by increasing experimental complexity, large data volumes, and growing demands for collaboration across diverse fields. To address these challenges, we present an integrated data analysis platform for the versatile experiment spherical torus (VEST), a university-scale device at Seoul National University. Designed in alignment with FAIR principles and the integrated modeling and analysis suite (IMAS) standard, the platform integrates three core components: an automated data processing pipeline, a remote IMAS-compliant database, and a unified analysis library. This framework establishes a continuous workflow that links experimental data with modeling codes, spanning diagnostic processing, electromagnetic modeling, equilibrium reconstruction, kinetic profile fitting, and linear magnetohydrodynamic (MHD) stability analysis. Leveraging this platform, we conducted a comprehensive analysis of VEST’s operational space and associated MHD stability characteristics. The results indicate that plasma performance is primarily constrained by current-driven instabilities-specifically n = 1 ideal kink and peeling modes, as well as resistive n = 1 and n = 2 modes. The ideal n = 1 kink mode, in particular, imposes a hard operational boundary in the low edge safety factor ( q a ) regime, while edge-localized peeling modes are frequently destabilized when the q a approaches integer values. In contrast, the achieved normalized beta (β_N) remains below the ideal Troyon limit. This confirms that performance is not constrained by pressure-driven instabilities and suggests that plasma density could potentially be increased. This platform lays the groundwork for data-driven research at VEST and provides a practical model for other small-scale facilities to adopt international data standards.