In 2023, an energy turnover of 1 gigajoule was targeted. Now the researchers have even achieved 1.3 gigajoules and a new record for discharge time on Wendelstein 7-X: the hot plasma could be maintained for eight minutes.

articularly heat-resistant divertor baffle plates are used to dissipate the largest heat flows at Wendelstein 7-X. They are part of the inner wall, which is now cooled by a system of 6.8 kilometres of water pipes since the completion of the device. No other fusion facility in the world currently has such a comprehensively cooled inner wall. The plasma heating consists of three components: the newly installed ion heating, the heating by neutral particle injection and electron microwave heating. For the current record, the electron microwave heating system was particularly important because it delivers large amounts of power over periods of several minutes. The energy turnover of 1.3 gigajoule was achieved with an average heating power of 2.7 megawatts, whereby the discharge lasted 480 seconds. This is also a new record for Wendelstein 7-X and one of the best values worldwide. Before the completion works, Wendelstein 7-X achieved maximum plasma times of 100 seconds at much lower heating power.

Within a few years, the plan is to increase the energy turnover at Wendelstein 7-X to 18 gigajoules, with the plasma then being kept stable for half an hour.