Europe signs contract to manufacture ITER Neutral Beam Drift Ducts

Fusion for Energy (F4E) and Research Instruments (RI) will collaborate to manufacture the Drift Ducts, a component linking ITER's Neutral Beam Injectors with the Vacuum Vessel. The contract was signed in December and the teams met in Barcelona shortly after to kick off the project. The German company will build two units, following the design by ITER Organization and working with a chain of specialist subcontractors.

The Drift Duct will sit at the front end of the injector's bus-sized vessel. There, it will allow the particle beam to travel into the vacuum vessel's connecting duct (on its way) to heat the plasma. The location, sandwiched between heavy, rigid components, called for a flexible interface. Thanks to a bellows shape (like an accordion), the Drift Duct will be able to absorb small displacements while securing a leak-tight passage. The component is under ultra-high-vacuum and must meet stringent tolerances, cleanliness and safety requirements.

Inside, the duct is lined with a sleeve of copper alloy, with cooling water pipes running through it. This shields the duct bellows from super-hot particles escaping the beam. To shape and join the different parts, RI will rely on its in-house resources and technologies, as well as those of industrial partners, skilled in techniques like electron beam welding or bellows fabrication. Once assembled, each duct will weigh over 5 tonnes and measure 2 meters in diameter.

Given ITER's assembly strategy, the Drift Ducts follow a tighter schedule than other components of the Neutral Beam system. They are required before the Start of Research Operations, even though Neutral Beam Heating itself will only be added in later experimental phases. "With sound planning, technical rigour and, of course, teamwork, we will strive to deliver the two units on time, while meeting the complex requirements," says Gonzalo Micó, F4E Project Manager.

"We are pleased that RI has been awarded this contract, a recognition to our expertise in high-precision components for demanding applications. The Drift Ducts are technically challenging and require advanced fabrication capabilities and strict quality control. We look forward to collaborating with F4E and ITER Organization, strengthening further our long-term partnership and role as a reliable supplier," says Alexander Navitski, Head of Business Section.