Opinion: An artificial sun briefly blazed under the English countryside. One day, it could change everything
However, it’s very hard to harness nuclear fusion. Without protection, the very high temperatures needed would damage the reactor in which the process takes place, so scientists use magnetic fields to contain the heated fuel. These magnetic fields are essentially force fields that protect the surrounding material. Unfortunately, the heated deuterium makes its own magnetic fields, which interfere with the force fields. The JET facility generated fusion in this way. The extreme heat and pressure generated by the reaction means this is likely to be the JET’s last hurrah. It is unlikely it will be used again.