Scientists achieve fusion ignition, a major milestone in clean energy production

Scientists have just crossed one of the most important thresholds in the quest for fusion energy. A team at Lawrence Livermore National Laboratory has created the first known fusion reaction with a net energy gain — that is, it produced more energy than it consumed and ignited. The researchers achieved the feat on December 5th, when they used 192 lasers at the National Ignition Facility to blast a cylinder containing frozen hydrogen surrounded by diamond.

The reaction, which generated a flurry of X-rays, struck a fuel pellet of deuterium and tritium with 2.05 megajoules of energy. That, in turn, led to a wave of neutron particles and 3.15 megajoules of output. That gain was 'only' equivalent to about 1.5lbs of TNT, but that was enough to meet the criteria for fusion ignition.

The development has been a long time coming. The National Ignition Facility started work in 2009, but it wasn't until 2014 that the installation's laser-based fusion technology produced a meaningful volume of energy. Progress accelerated in the past year, however. Lawrence Livermore generated a much larger amount of energy last August, equivalent to 70 percent of that from the lasers. An attempt in September generated 1.2 megajoules using the 2.05-megajoule blast.

The lab and the Energy Department are quick to caution that "many" advancements are still necessary before fusion reactors are practical enough to power homes. During a presentation, scientists said they needed to improve the number of reactions per minute, simplify the process and otherwise make it easily repeatable. And of course, they need to improve scaling — a reactor would have to power enough households to justify its existence.

The Energy Department is in the midst of rebooting a coordinated fusion power effort, however. During the event, officials also noted that a functional plant wasn't as far off as you might think. While they didn't commit to a timeframe, they said it was less than the 50 or 60 years they might have predicted in the past. You might see the first commercial fusion reactor in your lifetime, to put it another way.

The technology could be vital to limiting global warming and otherwise fighting climate change. While renewable energy sources like solar and wind power are more eco-friendly than coal, they don't always meet demand and can require large amounts of land. Solar also isn't as effective in regions where sunlight can be limited. Sufficiently powerful fusion reactors could achieve the dream of clean powerplants that have enough capacity to serve large populations without the radioactive waste of nuclear facilities.

[original story: Engadget]