To confine ITER’s superhot plasma, the powerful magnets of the machine will need to be cooled at temperatures close to absolute zero in order to reach a superconducting state. The magnets will be surrounded by thermal shields, which will insulate them from high temperatures to help them remain cold. The cryoplant is the source of the chilling temperatures required. One could describe it as a massive refrigerator of the ITER machine.
One of the facilities that F4E is responsible for, as part of its contribution to ITER’s cryogenic system, is the Liquid Nitrogen -LN2- plant. A pair of one oil brake turbine and one turbine booster will need to be installed, in each of the two cold boxes of the LN2 plant, to help the nitrogen refrigerators cool the thermal shields of the magnets.
F4E in collaboration with Air Liquide and Cryostar have celebrated a manufacturing milestone, following the successful factory acceptance test of all four turbines. In spite of their diameter, which is not more than 15 cm, these tiny pieces of equipment will generate enough cooling power to keep the thermal shields extremely cold. The structure containing the turbines with all ancillary systems has a 3.8 x 2.5 m footprint. It has taken eight months to manufacture them and they will be delivered on the ITER site this autumn.