Is the dream of fusion finally here?
In recent days, scientists who study fusion — the reaction that powers the sun — have been emailing one another about a significant milestone in their field.
The discussion kicked into overdrive on Sunday when The Financial Times published an article saying that scientists at Lawrence Livermore National Laboratory in California had achieved ignition, a state in which more energy was produced in an experiment than laser beams had put into it.
Then on Monday, the federal Energy Department announced that it would present a “major scientific breakthrough” achieved at the lab.
Here’s what you need to know about fusion energy and the announcement set for Tuesday.
At 10 a.m. Eastern time on Tuesday, Jennifer Granholm, the energy secretary, and other federal officials will make an announcement in Washington, D.C. You can watch it on the Energy Department website or in the video player embedded above.
Fusion is the thermonuclear reaction that lights up the sun and other stars — the fusing of hydrogen atoms into helium. The mass of helium is slightly less than the original hydrogen atoms. Thus, by Einstein’s iconic E=mc² equation, that difference in mass is converted into a burst of energy.
It took place at Lawrence Livermore National Laboratory, which plays a key role in developing and maintaining the U.S. nuclear weapons arsenal. Among its numerous initiatives is the National Ignition Facility, or NIF.
The main purpose of NIF, built at a cost of $3.5 billion, is to conduct experiments that help the United States maintain its nuclear weapons without nuclear test explosions. Proponents said it also could advance fusion research, potentially leading to viable commercial power plants.
Last year, Livermore scientists reported a major leap, a burst of energy — 10 quadrillion watts of power — that was 70 percent as much as the energy of laser light hitting the hydrogen target.
But the burst — essentially a miniature hydrogen bomb — lasted only 100 trillionths of a second.
Fusion that could be produced in a controlled fashion on Earth could mean an energy source that does not produce greenhouse gases like coal and oil, or dangerous, long-lived radioactive waste, as current nuclear power plants do.
But the laser experiments at NIF are a long way from being practical enough to produce electricity the way a commercial power plant does.
Nevertheless, successful experiments could point the way to developing technologies usable outside a laboratory setting.