Temperature Model Identification of FTU Liquid Lithium Limiter

In this brief, the thermal model identification of the limiter surface placed in nuclear fusion plants facilities is presented. Experimental data measured at the Frascati Tokamak Upgrade (FTU) have been considered in order to identify a nonlinear dynamical model of the temperature distribution over the cooled lithium limiter used in the FTU. Three data-driven approaches have been followed: 1) a linear autoregressive (ARX) model; 2) a nonlinear ARX model; and 3) a Hammerstein model. The selection procedure of the relevant physical quantities will be outlined and a comparison among the obtained models will be given.