Preliminary design activities began in 2004 at the French Alternative Energies and Atomic Energy Commission (CEA), the procurement agreement was signed in 2017 with the European Domestic Agency Fusion for Energy, and a final design was achieved in 2020. Designing and manufacturing the complex components was particularly challenging, as they will be exposed to the intense magnetic field inside the machine and the high neutron flux from the fusion reaction. The cold valve boxes will operate within an exceptionally large temperature range: from 4K (
minus 269 °C) when distributing supercritical helium to the cryopumps, to 200 °C when hot gas is blown into the boxes during the regeneration process.
The functional tests presently performed in the 澳门六合彩高手 vacuum lab will be followed by cold tests at liquid nitrogen temperature (80K, minus 196 °C). An installation is being prepared in the cryoplant to test at 4K.