Inside fusion reactors, hydrogen atoms fuse together in a plasma at extreme temperatures to release energy. But just like a campfire needs fresh wood to keep it going, the plasma requires a steady supply of fuel to continue burning. In large tokamaks like JT-60SA and ITER, pellet injector systems will launch frozen pellets of protium, deuterium or tritium at high speed into the plasma to refuel and control it.
Despite their crucial role, there are only few suppliers worldwide with experience in manufacturing injector components. In fact, the recent Fuel Cycle Mapping report by F4E and EUROfusion identified this as an important technology gap to be tackled in Europe. “Fusion laboratories like CIEMAT, CEA, HUN-REN, or IPP have developed or operated injector concepts. Now we need to take the expertise into industry and build a European supply chain ready for large-scale fusion devices,” explains Mario Cavinato, Project Manager at F4E.
In this spirit, Fusion for Energy (F4E) organised an hybrid (in person and online) Information Day, hosted by the Max Planck Institute for Plasma Physics (IPP) in Garching, Germany. More than thirty representatives from industry and research attended the event to learn more about the characteristics of pellet injector systems and future business opportunities. “The goal was to stimulate interest in this technology and connect players with the right competences. In particular, partnerships between laboratories and companies will be key to bring the components to a mature stage,” says Cavinato.
The next step for F4E will be the launch of a Call for Tender to develop and manufacture pellet sources for JT-60SA and beyond. The source is the first part of the injection system. It will freeze the hydrogen gas, extrude an ice rod from it and cut it into millimetre-sized pellets at a very fast rate. Then, an accelerator will shoot it through a guiding tube with enough speed (up to 600 m/s)to penetrate the core of the plasma. F4E is working with the Spanish company SENER to deliver a centrifuge pellet accelerator for JT-60SA. The components will be qualified at a specialised testbed in IPP, also funded by F4E.
In ITER, the pellet injector system is under the scope of the United States. Therefore, the contribution to the JT-60SA, the experiment financed by Europe and Japan currently under upgrade, offers an invaluable opportunity to gain experience. “This project will allow us to develop know-how in a technology that will be deployed in next-generation fusion reactors,” asserts Cavinato.
