Thermal fluxes due to plasma-wall interactions: Experimental measurements and numerical analyses

The experimental results obtained from thermonuclear fusion devices highlight an uneven thermal flux distribution on the first wall, due to enhanced localized plasma-wall interactions. A numerical model to evaluate these thermal fluxes was implemented taking into account both the axisymmetric and the localized energy contributions. This paper illustrates the model, its approximations and the required input data to be taken from experimental measurements. The results of the thermal nonlinear dynamic analyses carried out for the RFX first wall and vacuum vessel are presented and compared with the vessel temperature measurements acquired during the experimental sessions. The simulations of the thermal responses show that more than 40% of the total plasma energy is concentrated in the region where the plasma-wall interaction is enhanced by the presence of locked modes.