Europe’s premier fusion energy device, JET, is gearing up for world-first experiments at Culham next year.

The JET tokamak

The JET machine – image credit: EUROfusion

The EU’s JET facility – operated by the UK Atomic Energy Authority on behalf of the EUROfusion research consortium – will carry out key experiments using two hydrogen isotopes, deuterium and tritium (D-T). These are the fuels expected to supply commercial fusion power plants. Next year will see the first ever D-T experiments with the same inner-skin on the machine walls as will be used in future fusion machines – a mixture of beryllium and tungsten. These materials erode more slowly and do not soak up as much fuel as the previous JET carbon wall did.

In order to be able to use tritium in JET, a substantial programme of refurbishment and preparation has taken place. This means tritium can now be moved from JET’s Active Gas Handling System (the system which processes and handles gas mixtures containing tritium) to the central chamber or ‘torus’ of the machine.

The results of the experiments will be very important for ITER – the international fusion machine currently being built in the south of France, seen as the stepping stone to fusion power stations. ITER is not planning to use tritium fuel until the 2030s, so the ability to do tritium fuel experiments in JET is a huge opportunity for the fusion community.

Lorne Horton, JET Programme Leader at EUROfusion, said: “These experiments are the culmination of more than a decade of work and will provide unique results of high value to the fusion community.  We are very keen to get started.”

During 2020, JET has prepared by running experiments with deuterium only, with extremely impressive performance. It has broken its own records for deuterium-deuterium fusion neutrons and plasma heating power – boding well for tritium operations next year. Much of this has been achieved despite having to implement socially-distanced working at the facility, with the number of staff in the control room restricted to a core team.

JET is now undergoing final preparations for using tritium. These include checking on measurement systems and finishing the commissioning of all the engineering systems needed for the all-important tests in 2021.

Main photo: the JET control room during experiments. Please note this photograph was taken before the coronavirus outbreak.

Share this page: