‘ cold valve boxes ’ will regulate the forced flow of supercritical helium to the eight cryopumps of the ITER vacuum system .
INNOVATION
Cold valve boxes for the ITER cryopumps
Text by Fusion for Energy
At Research Instruments , the four-tonne cold valve boxes will be equipped with final electrical wiring and pneumatic connections before undergoing factory acceptance testing . © RI , August 2022
About Fusion for Energy
Fusion for Energy ( F4E ) is the European Union organisation managing Europe ’ s contribution to ITER — the biggest scientific experiment on the path to fusion energy . This partnership of seven parties ( China , Europe , Japan , India , the Republic of Korea , the Russian Federation and the USA ), represents half of the world ’ s population and 80 % of the global GDP . Europe is responsible for nearly half of the project , while the other six parties contribute equally to the rest .
European contractors Research Instruments ( Germany ) and Cryoworld ( Netherlands ) are manufacturing eight ‘ cold valve boxes ,’ high-tech cryogenic components that are built to withstand the hostile environment near the plasma . After mechanical pumps perform the initial pumpdown of the ITER vacuum vessel and cryostat , powerful cryopumps will take over to attract any remaining molecules to the ultra-cold surface of their cryopanels . Eight cryopumps are planned to exhaust the vacuum vessel and the cryostat , each one equipped with numerous " cryopanels " that will be cooled down to 4.5 K ( minus 268.5 ° C ) by a flow of supercritical helium .
Two cold valve boxes loaded onto the truck for transportation from Cryoworld to Research Instruments , Netherlands , July 2022 . © RI
Supercritical helium
Regulating this flow of supercritical helium are the cold valve boxes associated with each pump . Equipped with cryogenic valves ( 25 per unit ), relief systems , and sensors for pressure and temperature , these components will manage cryogenic fluids in a wide range of temperatures — from super-cold ( -269 ° C ) to fairly hot ( 230 ° C ). High magnetic field , radiation , and space were part of the design constraints . The position of the cold valve boxes in the machine imposed special constraints on materials and welding , while regular " regeneration periods " for each pump complicated their design . Based on a contract for the final design and fabrication of the cold valve boxes awarded by the European Domestic Agency Fusion for Energy in 2018 , Research Instruments ( already involved in the manufacture of the ITER cryopumps ) contracted with Cryoworld BV for the torus and cryostat cold valve boxes . Cryoworld has already shipped four of eight units to Research Instruments , where final electrical wiring and connections will be installed , and factory acceptance testing carried out . Delivery to ITER is expected before the end of the year . www . valve-world . net Valve World November 2022
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