Powerful heating systems will work in tandem to raise the temperature of the ITER plasma close to 150 million °C. Inside a hermetically sealed vacuum vessel, the hot gas will float without touching its walls because it will be magnetically confined by large superconducting coils. Given the fact that much of this has not been tried before at such scale, a test bed called MITICA (Megavolt ITER Injector and Concept Advancement) has been built in Padua in order to test a full-scale prototype of a Neutral Beam Injector (NBI) that will generate a power of 16.5 MW. It will be one of the heating systems deployed in ITER to keep the fire burning of its voluminous plasma. MITICA counts with in-kind contribution by means of components, or by skills operating the equipment, from Europe, Japan, ITER Organization, and Consorzio RFX. The lessons drawn from the fabrication of its components, their performance, operation, maintenance, and repairs, will feed directly into the ITER. It’s incredible learning curve preparing scientists, industry and laboratories for the next steps.
MITICA’s latest piece of equipment to have successfully completed the on-site acceptance tests is the cryopump. It results from the collaboration of F4E with SDMS and Ravanat during the last five years, and counts with an investment of several million EUR. The meaningful involvement of colleagues from ITER Organization and Consorzio RFX, acting as one team, has been fundamentally important in reaching this significant milestone. Think of the cryopump as a powerful hoover that will suck any air, dust, and impurities trapped inside the beam source. Every time a new cycle of operations needs to start, the cryopump will create the necessary vacuum so that the ions generated in the source can be accelerated to form a beam with an energy of 1 MeV.
This piece of equipment is 8 m long by 2.8 m high and 0.45 m wide. It’s much larger than the standard cryopumps in the market. This partly explains the complexity of the dimensional checks that needed to be performed and the high degree of precision required. The cryopump has some additional particularities. For example, it is composed of two pumping assemblies, each of them consisting of a frame with 32 pumping sections.
The work of this component has been followed by Josep Benet, F4E Project Manager, who was present at the site acceptance tests in Padua. “Now that we completed this round of tests, we can safely say that we made it. The good collaboration with our two contractors, SDMS and Ravanat, and the solid team spirit with colleagues from ITER Organization and Consorzio RFX have been instrumental in completing this task.” Next, the cryopump will be inserted inside MITICA’s beam vessel. Dani Dupuy, F4E Technical Officer, explains what is next in the pipeline. “All lessons learned will be transferred to the procurement of three ITER cryopumps serving the Neutral Beam, and the Diagnostics systems.”