Control of the vacuum vessel temperature in RFX

The vacuum vessel of RFX has been designed to operate between room temperature and 350°C during experimental sessions and during first wall conditioning operations. The temperature control system of the vacuum vessel consists of the measurement and the heating systems, connected to the RFX central control system, SIGMA. The data acquisition electronics supplies the temperature signals to the heating system and to SIGMA. The heating system provides uniform heating in both toroidal and poloidal directions. SIGMA allows different modes of operation and handles the alarm signals. After a description of the main components, the results of the first two years of operation are presented