Integrated equilibrium reconstruction and MHD stability analysis of tokamak plasmas in the EU-IM platform

摘要

I - Introduction The performance and operational limits of present and future Tokamak plasmas are influenced by the equilibrium profiles, shape and position e.g. vertical position stability in strongly shaped plasmas or onset of disruptive instabilities driven by profile gradients. Free boundary plasma equilibrium profiles can have a strong effect on the interpretation of all physical phenomena occurring in the plasma e.g. core/edge MHD stability characterization, plasma transport and auxiliary heating. It is thus a fundamental task to determine the plasma equilibrium using as many available input experimental data e.g. magnetic diagnostics (magnetic flux and poloidal magnetic field), density and temperature diagnostics and polarimetry diagnostics. In the framework of the EUROfusion Work Package on Code Development for Integrated Modelling, a scientific Kepler [1] workflow for the reconstruction of Tokamak plasma equilibrium was developed (Figure 1). It includes consolidated reconstruction codes such as EQUAL [2], CLISTE [3], EQUINOX [4] and post-processing error bar estimator SDSS [5], all using the same physics and machine data ontology and methods for accessing the data used in the European Integrated Modelling (EU-IM) framework [6]. Presently implemented modules (actors) are interfaced to "data bundles" e.g. magnetic sensors, Thomson scattering diagnostics as well as poloidal field coil data, are packed into a "machine bundle", to facilitate the data exchange in the workflow through selfconsistent datasets. The reconstruction codes feature polynomial or spline (natural or B-spline) representation for the profiles and non-uniform spatially distributed knots for the equilibrium regularisations are implemented. Equilibrium reconstructions relying on magnetics data only (magnetic diagnostic, PF/TF coils and iron core) or with added internal data (motional Stark effect, polarimetry or pressure) may be performed.