Applications of Bayesian temperature profile reconstruction to automated comparison with heat transport models and uncertainty quantification of current diffusion

M. Irishkin (1) , Frédéric Imbeaux (1) , T. Aniel (1) , J.F. Artaud (1)

1 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique

In the context of present and future long pulse tokamak experiments yielding a growing size of measured data per pulse, automating data consistency analysis and comparisons of measurements with models is a critical matter. To address these issues, the present work describes an expert system that carries out in an integrated and fully automated way i) a reconstruction of plasma profiles from the measurements, using Bayesian analysis ii) a prediction of the reconstructed quantities, according to some models and iii) a comparison of the first two steps. The first application shown is devoted to the development of an automated comparison method between the experimental plasma profiles reconstructed using Bayesian methods and time dependent solutions of the transport equations. The method was applied to model validation of a simple heat transport model with three radial shape options. It has been tested on a database of 21 Tore Supra and 14 JET shots. The second application aims at quantifying uncertainties due to the electron temperature profile in current diffusion simulations. A systematic reconstruction of the Ne, Te, Ti profiles was first carried out for all time slices of the pulse. The Bayesian 95% highest probability intervals on the Te profile reconstruction were then used for i) data consistency check of the flux consumption and ii) defining a confidence interval for the current profile simulation. The method has been applied to one Tore Supra pulse and one JET pulse.

Mots clés: Fusion; Bayesian reconstruction; Plasma reconstruction; Bayesian analysis

Domaines: Physique [physics]; Applications [stat.AP]

M. Irishkin, Frédéric Imbeaux, T. Aniel, J.F. Artaud. Applications of Bayesian temperature profile reconstruction to automated comparison with heat transport models and uncertainty quantification of current diffusion. Fusion Engineering and Design, 2015, 100, pp.204-219. ⟨10.1016/j.fusengdes.2015.05.075⟩. ⟨cea-02193716⟩