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Wendelstein 7X

The Client

The Karlsruhe Institute of Technology (KIT) is one of the largest and most prestigious research and education institutions in Germany. In the context of the Wendelstein 7-X project, KIT is responsible for the supply of the ECRH microwave plasma heating system.

The Challenge

With the ever increasing demand for energy, it is inevitable that world energy supply systems will face integral restructuring in the long term. Nuclear fusion is considered by many to be a powerful alternative to traditional energy production. The Wendelstein 7-X device aims to demonstrate the suitability of the stellarator device as a power plant. It is a project lead by the Max Planck Institute for Plasma Physics (IPP).

Ignition of a fusion reaction requires a heating system capable of heating the plasma to 100 million degrees Celsius. To reach this level, the Wendelstein 7-X experiment needs highly efficient microwave gyrotrons which are capable of generating 1MW full power. This is more than one hundred times the duration of the pulses already achieved and meant advancing into an entirely new technological dimension. This process was pushed forward by the close cooperation between Thales Electron Devices (TED) and KIT.


A contract between KIT and Thales was settled to develop and manufacture the series gyrotrons. The first step of this collaboration was the development of a prototype gyrotron for W7-X with an output power of 1 MW for CW operation at 140 GHz.
The series gyrotrons (TH1507) were then ordered from Thales. The first in the series was tested successfully at KIT and then IPP. It fulfilled all the specifications and no specific limitations were observed during the acceptance test. KIT subsequently proposed some technical enhancements for the full series.

Thales successfully implemented these new concepts and achieved the series production of the TH1507 gyrotron. Over the course of this project, Thales made breakthroughs that stabilised the supply chain and improved the reliability and series production of microwave tubes in continuous operation.