Fusion Energy Breakthrough: Video and How to Watch

Scientists studying fusion energy at Lawrence Livermore National Laboratory in California announced Tuesday that they have passed a major milestone in reproducing the sun’s energy in the laboratory.

For decades, scientists have said that fusion, the nuclear reaction in which stars glow, could provide abundant energy for the future.

The results, announced Tuesday, are the first fusion reactions in a laboratory setting to actually produce more energy than was needed to start the reaction.

“The fact that we’re able to get more energy out than we put in provides existential evidence that it’s possible,” said Mark Herman, director of the Weapons Physics and Design Program at Livermore Lab. “It can build, improve and get better, and has the potential to be an energy source in the future.”

From an environmental standpoint, nuclear fusion has always been attractive. Inside the sun and stars, fusion is constantly combining hydrogen atoms into helium, producing the sunlight and warmth that bathe the planets.

In experimental reactors and laser laboratories here on Earth, fusion lives up to its reputation as a very clean energy source, without the pollution and greenhouse gases from burning fossil fuels, or the dangerous long-lived radioactive waste that current nuclear power plants produce, and it uses uranium split to generate energy.

However, there is always a nagging caveat. For all the efforts scientists have made to control fusion’s irregular energy, their experiments consume more energy than fusion reactions produce.

On the morning of December 1, things changed. 5. Just over a week ago, 192 giant lasers at the lab’s National Ignition Facility blasted a small cylinder, about the size of a pencil eraser, containing frozen hydrogen nuclei encased in diamonds.

A laser beam enters the top and bottom of the cylinder, vaporizing it. This creates an inward X-ray shock that compresses BB-sized deuterium and tritium (heavier forms of hydrogen) fuel pellets.

In a brief instant lasting less than a trillionth of a second, 2.05 megajoules of energy—roughly equivalent to a pound of TNT—struck the hydrogen projectile. A mass of neutron particles—the products of fusion—came out, carrying the energy equivalent to about 1.5 pounds of TNT, or an energy gain of about 1.5.

This crosses what laser fusion scientists call ignition threshold, the dividing line at which the energy produced by fusion equals the energy of the incident laser light that started the reaction.

The successful experiment finally achieved the ignition goals promised when construction of the National Ignition Facility began in 1997. However, when it began operating in 2009, the facility produced barely any fusion, an embarrassing disappointment after a $3.5 billion investment by the federal government.

In 2014, the Livermore scientists finally reported some success, but produced negligible amounts of energy—about as much energy as a 60-watt light bulb consumes in five minutes. Progress in the ensuing years was minimal.

Then, last August, the facility produced an even larger burst of energy — 70 percent the energy of a laser.

The researchers then conducted a series of experiments to better understand August’s surprising success, Dr. Herrmann said, in an effort to increase the laser power by nearly 10 percent and improve the design of the hydrogen target.

The first 2.05 MJ laser shot was made in September, and the first attempt produced fusion energy of 1.2 MJ. In addition, the analysis showed that the spherical hydrogen particles were not squeezed evenly, and part of the hydrogen gas was basically ejected from the side and did not reach the fusion temperature.

The scientists made some tweaks that they thought worked better.

“The prediction before the shooting was that it might triple,” Dr. Herman said. “In fact, it went up more than that.”

The main purpose of the National Ignition Facility is to conduct experiments to help the United States maintain its nuclear weapons. By conducting these nuclear reactions in the laboratory on a smaller, destructive scale, scientists aim to replace the data they used to gather from underground nuclear bomb explosions, which the United States stopped in 1992.

The facility’s larger fusion output will generate more data, “enabling us to maintain confidence in our nuclear deterrent without further subsurface testing,” said Dr. Herman said. “It just expands our capabilities there and allows us to work with less extrapolation and more confidence.”

“Our goal is to demonstrate that one can ignite a thermonuclear fuel in the laboratory for the first time,” said Riccardo Betti, lead scientist at the University of Rochester’s Laser Energetics Laboratory, who was not involved in this particular Livermore experiment.

“It’s been done,” he added. “So it’s a good result.”

The experiment’s impact on energy generation is more preliminary.

“It’s been a very long and difficult road from there to actual energy on the grid,” said Dr. Betty said.

Nuclear fusion is an inherently emission-free energy source, helping to reduce the need for coal and natural gas-fired power plants that spew billions of tons of global-warming carbon dioxide into the atmosphere each year.

But fusion is unlikely to emerge on a widespread, practical scale for decades, if ever.

Most climate scientists and policymakers say the world must achieve net-zero emissions by 2050 to meet the goal of limiting warming to 2 degrees Celsius, or even the more ambitious 1.5 degrees Celsius goal.

henry fountain Contribution report.

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