What do an airplane, a thermostat and a human body have in common? They all share a feedback mechanism which is able to keep a certain physical quantity within a prearranged and optimal value. The thermostat controls for example the home heating system, switching it on or off, depending on the temperature it measures inside the house and in order to keep the preset temperature value. The human body does the same with its own temperature or with the blood Ph value. Rfx experiment is a strong and valuable expertise in of plasma feedback mechanisms. Piero Martin will illustrate them in the ninth episode of the Factory of the Stars. A fusion plasma needs to be stable in order to efficiently produce energy. To study this process in Rfx a series of magnetic probes measure the magnetic filed perturbation. These data are compared in real time with optimal pre- set values. If the systems spots any variation it activates 192 magnetic coils, which are distributed all over the Rfx surface. These couls produce magnetic fields that are able to adjust the perturbations. 

Project manager: Francesco Suman Shooting and editing by Elisa Speronello Subs: Anna Bellettato