This circle is for the ring
In April, it will be lifted in the Assembly Hall by the overhead crane, and transported to the Tokamak pit to be installed on nine temporary support structures. These temporary supports, weighing approximately 5 tonnes and containing vertical actuators, will be used until completion of vacuum vessel assembly in the pit; then, PF6 will be raised to its final position using hydraulic jacks and aligned.
Inside of the circle formed by the temporary supports, the assembly teams will be installing a first, spare set of pre-compression rings and the central column of the in-pit assembly tool.