The National Ignition Facility is a 3-stadiums-wide building, and a part of the Lawrence Livermore National Laboratory, whose main interest is to make nuclear fusion possible. On Sep. 29, the $3.5 billion laser machine inside the NIF has proved the theory was right by firing its 192 laser beams on a tiny frozen hydrogen pellet, producing the fusion of some tritium and deuterium atoms.
“In my mind, to have accomplished this shot is an almost unfathomable scientific achievement,” Paul Drake, a physicist at the University of Michigan using NIF as a proving ground for studying supernova physics in the laboratory, told Wired.com. “I’ve had a lifetime of experience of big science facilities, and find myself in awe of [the NIF team] having made this thing work this fast.”
The hydrogen pellet had been encased in a tiny plastic pellet at the center of another 30-foot-diametral metal sphere. The lasers delivered 1 megajoule, or the power equivalent of a car traveling at 100 mph.
Still, the fuel in the middle has not been perfect – deliberately. The scientists taught their lesson of the kid playing with fire and didn’t risk creating a fusion they couldn’t ultimately have controlled. Instead, they fired the lasers at 75 percent of their capacity on the imperfect fuel.
“The facility is like a new car engine,” said Richard Petrasso, a fusion scientist at MIT who works with the machine’s diagnostic equipment. “You don’t hit the pedal all the way down to the ground the first time. You have to tune it to get all of the conditions just right – the laser, the diagnostics and the surface of the capsule.”
The test’s results were, nevertheless, more than satisfying: 10 trillion neutrons had been emitted during the experiment, signaling the fusion of some atoms in the heavy hydrogen pellet. A real fusion reaction, though, would have to emit 1,000 times more neutrons, said Edward Moses, the head of the NIF team.
“The last thing we’d ever think about doing is playing cowboy with this thing,” he also said. Throughout the next year or two leading up to an all-or-nothing firing, the facility will make similar integrated shots about once a month.
The team expects to have successfully realized fusion within two years, with progressive increase of power until then. The fact is that the facility doesn’t only research benign fusion, but also government-ordered projects, like simulating fusion bomb explosions without the actual detonation. As Moses says, “Strategic security is also part of the mission.”
My guess is that the military will first take advantage of the discovery and that actual results will be seen in real life a long time after military testing. Remember, nuclear fusion is a theoretically unlimited source of energy and whoever owns it has to use it responsibly – more than ever.