Europe moves ahead with the manufacturing of its gyrotrons for ITER

Gyrotrons are a vital technology to heat the ITER plasma to over 100 million ºC and sustain the fusion reaction. These components, part of the Electron Cyclotron Heating system, essentially turn electricity into powerful microwaves. The waves are tuned at a frequency of 170 GHz so that, once the beam is shot inside the device, they efficiently transfer their energy to the electrons in the plasma. Each gyrotron will deliver 1 MW, around 1,000 times the power of a kitchen microwave. They must operate for pulses of up to one hour – an exceptionally long interval for equipment of this kind.

Fusion for Energy (F4E) is currently working to provide six units, out of the 24 needed in the initial ITER plan. However, the new baseline has scaled up Electron Cyclotron Heating: 48 gyrotrons will be deployed for the start of research operations, and another 24 for the deuterium-tritium phase. This will mean more units for Europe to produce, and thus more opportunities for industry to gain hands-on expertise in this complex, strategic technology.

In 2023, following a joint tender with the Divertor Tokamak Test (DTT), F4E partnered with Thales. Under a contract amounting to around 20 million EUR, the French firm signed to provide the six ITER gyrotrons (while 16 others will be supplied separately to DTT).

This year, the project is moving into a decisive stage. Following the completion of the Final Design Review (FDR) last December, teams are getting ready to start manufacturing. Experts from F4E, ITER Organization and industrial partners held regular online and in-person meetings to conclude the FDR for over a year.

“Thanks to our teamwork, we closed all issues for the gyrotron design, ensuring optimal performance and seamless integration with other systems, such as the water cooling pipes,” explains Paco Sánchez, F4E Project Manager.  The work also drew on the experience from the pre-series unit built by Thales for DTT. This prototype was tested at Falcon, a testbed for gyrotrons at the Swiss Plasma Center (SPC) financed by F4E, which delivered valuable lessons to improve the final design.

Additionally, experts from KIT, SPC and NKUA provided support in technical aspects. F4E has been working with these laboratories since 2008 to leverage on their engineering and physics knowledge in the field of Electron Cyclotron Heating. Italy’s CNR is also contributing to test and qualify some FALCON testbed equipment.

“Thales is honoured to be at the forefront of the energy transition through its critical contribution to ITER. By supplying high-power gyrotrons for ITER, we strengthen our leadership in high-power microwave technology. This collaboration reflects our technical expertise, as well as the strength and enduring success of our strategic partnership with F4E, EUROfusion, and European fusion laboratories,” says Antoine Loidreau, Director of Space, Defense, & Science, Microwave and Imaging Sub-systems at Thales.

In parallel, the Spanish company GTD is developing bespoke control systems. These electronics will be used to process signals from the gyrotrons and adjust their operation in real time. “We have been collaborating closely with F4E for more than five years in Electron Cyclotron projects. The closure of the FDR was a very significant milestone for GTD and our team. The project has been both technically challenging and deeply rewarding, and we are proud to now move into the manufacturing phase, where the design will become a reality,” comments Oriol Picas Prat, Instrumentation and Control Engineer at GTD.

In addition to the gyrotrons, F4E is contributing to other parts of the Electron Cyclotron system, including power supplies as well as waveguides and launchers. Furthermore, Europe’s construction teams are currently working on the design of new buildings to host additional heating equipment.