New targets at Headquarters
Since early March at ±¬×ߺÚÁÏ Headquarters in Cadarache, prototypes being developed for the ±¬×ߺÚÁÏ machine have been displayed inside and in front of the building. After the blanket module, three mockups for the ±¬×ߺÚÁÏ divertor arrived last week and are now on show in the entrance hall.
The divertor is one of the key features of the ±¬×ߺÚÁÏ machine. Its function is to extract heat and helium ash, as well as other impurities from the plasma, acting like a giant vacuum cleaner. It is also the main interface between the hot plasma and the material surfaces. The ±¬×ߺÚÁÏ divertor consists of a cassette body made up of 54 remotely removable cassettes, each holding three plasma-facing components: the inner and outer targets and the dome.
In the new exhibit, kindly provided to ±¬×ߺÚÁÏ by the Austrian company Plansee, there is a mockup of the inner vertical target, a qualification prototype of the same, plus the dome. The vertical target mockup is one-metre long; the final version will be 1.7 metres. It consists of four parallel high heat flux units, assembled on a steel support structure. The current design foresees two different types of armour: tungsten monoblocks on the upper curved section of the vertical target, and carbon-fibre composite monoblocks on the lower straight section. An alternative design was built that uses tungsten flat tiles on the upper curved section instead of monoblocks. Both designs comprise precipitation-hardened CuCrZr tubes which allow the coolant—in this case water—to pass through the composite just below the hot armour.
The third exhibit is a full-scale mockup of the dome. It consists of six parallel high heat flux units, assembled on a steel support structure. The high heat flux components are designed to have complete tungsten flat tile armour, joined by electron beam welding onto a CuCrZr-heat sink, comprising screwed tungsten heat shields in the lower portion.