Heat Flux Calculation Using Embedded Thermocouple in W-Coated CFC Tiles in the JET Tokamak
Surface temperature and heat flux measurements are important issues in high power fusion devices to guarantee safe plasma operation. In the JET tokamak, few embedded ThermoCouples (TC) located 1cm below the tile surface are used to measure the bulk temperatures of the CFC tiles (coated with about 20mm of tungsten with the ITER-like wall). We propose here to use an inverse thermal calculation based on Quadruple thermal method to locally deduce the surface temperature (thus on the W coating) and deposited heat flux. The calculation requires the position of the peak (provided by offline magnetic reconstruction) and the qualitative 1D-shape of the heat flux deposited on the target (determined with an empirical expression of the target heat load profile found in ASDEX Upgrade and JET).