European fusion reactor sets record for sustained energy
Excerpt: In experiments culminating the 40-year run of the Joint European Torus (JET), the world’s largest fusion reactor, researchers announced today they have smashed the record for producing controlled fusion energy. On 21 December 2021, the U.K.-based JET heated a gas of hydrogen isotopes to 150 million degrees Celsius and held it steady for 5 seconds while nuclei fused together, releasing 59 megajoules (MJ) of energy—roughly twice the kinetic energy of a fully laden semitrailer truck traveling at 160 kilometers per hour. The energy in the pulse is more than 2.5 times the previous record of 22 MJ, set by JET 25 years earlier. “To see shots in which it sustains high power for a full 5 seconds is amazing,” says Steven Cowley, director of the Princeton Plasma Physics Laboratory (PPPL). JET’s achievement doesn’t mean fusion-generated electricity will flow into the grid anytime soon, however. Researchers had to put roughly three times as much energy into the gas as the reaction produced. But the result gives them confidence in the design of ITER, a giant fusion reactor under construction in France, which is supposed to pump out at least 10 times as much energy as is fed in. “This is very good news for ITER,” says Alberto Loarte, head of ITER’s science division. “It strongly confirms our strategy.”.…