A small step in creating a controlled fusion-energy reaction was reported in the online journal Nature.
Scientists are mimicking the interior of the sun inside a laboratory by using 192 lasers to compress a pellet of fuel and generate a reaction in which more energy came out of the fuel core than went into it, the Washington Post reports.
A fusion reactor would run on a common form of hydrogen found in seawater and create little nuclear waste. It would be immune to a meltdown similar to the one at Fukushima, Japan.
Scientists from the National Ignition Facility at the Lawrence Livermore National Laboratory, said the results were not fusion “ignition,” the ultimate goal.
Only about 1 percent of the energy from the laser actually winds up in the fuel, with most of it getting absorbed by surrounding material — a gold cylinder called a hohlraum, and a plastic capsule within that — before it reaches the fuel, which coats the inside of the capsule and is made of two hydrogen isotopes, deuterium and tritium.
But the experiment worked as hoped. When briefly compressed by the laser pulses, the isotopes fused, generating new particles and heating up the fuel further and generating still more nuclear reactions, particles and heat. This feedback mechanism is known as “alpha heating” and is an important goal in fusion research.
The energy produced form the reactions won’t be available in a power plant, or anywhere else, anytime soon. The cost of the operation is about $5 billion.