In the storage ring, the RF system replenishes the energy lost by the electron beam, mainly due to the emission of synchrotron light.
The main elements of the RF system are the RF cavities, metal structures that confine electromagnetic fields oscillating in the range of microwave whose fundamental mode of resonance has a longitudinal oscillating electric field in the direction of propagation of the electrons. The RF cavities are part of the vacuum chamber of the storage ring. Passing through the cavity in the correct phase of the oscillating electric field, the electron beam receives the energy needed to replenish what was lost along its trajectory.
Coupled to the cavities, there is a low and high power RF system that includes control circuits, power amplifiers and transmission lines. The total RF power required includes losses on the accelerating cavities, in waveguides and components of the transmission line between the generator and the cavities.
Each superconducting cavity is housed in a cryostat, immersed in liquid helium at a temperature of 4.5 K (equivalent to -268.65°C). The operation of these cavities requires the installation of a complex cryogenic plant for recovery and liquefaction of helium. This system includes a number of devices, such as a liquefier, a reservoir, compressors, high thermal insulation transfer lines and helium pressure and level control in the cavities.