Participation in the Joint European Torus JET

Participation in the Joint European Torus JET

The JET tokamak – the largest fusion experiment in the world – is to come as close as possible to ignition of the plasma. By the end of 2021, it was generating the largest amount of energy ever released from a fusion facility. IPP is one of the participants in the scientific programme of JET.

JET, the Joint European Torus, went into operation in 1983. For the first time in the history of fusion research it was possible with JET in 1991 to release a substantial amount of energy through controlled nuclear fusion. For the duration of 2 seconds the device generated a fusion power of 1.8 megawatt.

This was achieved a second time in 1993 by the American TFTR (Tokamak Fusion Test Reactor) fusion experiment at Princeton, shut down in 1997. With a heating power of 30 megawatts TFTR released about 6 megawatts of fusion power. Five months later TFTR was able to increase this to 9 megawatts. While TFTR worked for the first time with a plasma composed of the proper reactor mix of deuterium and tritium, in 1991 JET used a "rarefied" plasma with a tritium content of only 14 per cent.

In 1997, JET also experimented with a fuel mixture of equal parts deuterium and tritium. This yielded a world record fusion power of 13 megawatts and a fusion energy of 14 megajoules. Sixty-five per cent of the heating power input was recovered by fusion. The plasma of JET is now only a factor of six away from ignition.

At the end of 2021, it succeeded in producing stable deuterium-tritium plasmas with ITER-relevant wall material (beryllium and tungsten), releasing an energy of 59 megajoules (more information in the press release). This more than doubles JET's own world record from 1997. Expressed in units of power (energy per time), JET achieved a power output of just over 11 megawatts averaged over five seconds.

Today, JET is the only machine capable of operating with the deuterium-tritium fuel mixture that will be used in ITER and commercial fusion power stations.  All other facilities study model plasmas of light hydrogen and deuterium.


 Technical data
 Major plasma radius2.96 metres
 Minor radii1.25 / 2.10 metres
 Magnetic field3.4 tesla
 Plasma current5 megaamperes
 Plasma heating50 megawatts
 Plasma volume80 cubic metres
 Plasma mixturehydrogen, deuterium, (tritium)
 Plasma temperature100 - 200 million degrees


Go to Editor View