Nuclear Fusion Produces Net Positive Energy in Breakthrough Experiment

Scientists have produced a fusion reaction that led to a net energy gain for the first time. The results from the Lawrence Livermore National Laboratory in California marks a substantial step on the long path toward producing clean energy from nuclear fusion.

White House Office of Science and Technology Policy Director Arati Prabhakar stated at a press conference revealing the accomplishment in Washington, DC, yesterday, “Last week, lo and behold, indeed, they shot a bunch of lasers at a pellet of fuel, and more energy was released from that fusion ignition than the energy of the lasers going in.” he added, ” I just think this is such a tremendous example of what perseverance really can achieve.”

A long time coming

Nuclear fusion occurs when atoms crash right into each other, “fusing” to produce a heavier atom and, in the process, release energy. In the sun and other stars, hydrogen nuclei fuse, producing helium and generating massive quantities of energy. To accomplish nuclear fusion on Earth, humans must warm atoms to remarkable temperatures– millions of degrees Celsius reason why achieving a net energy gain has been so challenging.

At 1:03 AM GMT-5 on December 5th, the national laboratory used 192 powerful lasers to compress a target of hydrogen isotopes (deuterium and tritium) just around the size of a peppercorn. The target is confined in a carefully crafted diamond shell (hohlraum).

“Today’s shells are almost perfectly round. They are 100 times smoother than a mirror, and they have a tiny tube attached to them that’s about a 50th the diameter of a hair through which the fuel is filled into the shell,” stated Michael Stadermann, Target Fabrication Program manager at Lawrence Livermore National Laboratory. “As you can imagine, perfection is really hard, and so we’ve yet to get there– we still have tiny flaws on our shells, smaller than bacteria.”

The experiment generated 3.15 megajoule of energy, approximately 50% more than the 2.05 megajoule the lasers used to induce the reaction. By doing so, achieving a scientific energy breakeven, the scientists accomplished what’s referred to as “fusion ignition.”

The power of a star

Harnessing the power of nuclear fusion could be game-changing– providing individuals white an infinitely abundant source of energy without the byproduct of greenhouse gas emissions or long-lasting radioactive waste. Doing so, however, relies on overcoming massive engineering obstacles. After decades of experimentation, yesterday’s announcement stands as a small but extremely significant triumph over one of those hurdles. Yet there is still a long way to go before nuclear fusion can meet any clean energy demands.

The United States government has been funding fusion energy research since the 1950s. Throughout the world, the search has gathered tens of billions of dollars in funding. And by late 2021, researchers with the Joint European Torus (JET) in the UK produced a record 59 megajoule of energy from nuclear fusion. The main problem is that until now, nuclear fusion in a laboratory has not been able to generate more energy than required to make the reaction occur, to begin with.

It’s a key milestone; however, there are still some essential caveats to keep in mind. One major factor is that the DOE is attributing this success to just the output of the rather inefficient lasers. It takes 300 megajoule of energy from the grid just to acquire the two megajoule of laser energy. So yesterday’s announcement rests on a limited interpretation of “net energy gain.”

The path to fusion

Lasers aren’t the only way to attain nuclear fusion. Other initiatives, including JET, consist of a magnetic device called a Tokamak to constrain and heat plasma. Whatever the approach, we’re likely decades from producing energy in this manner at a power plant. It’s going to require a lot more funding and small victories to get there, yesterday’s statement being one of them.

“With real investment and real focus, that timescale can move closer,” Kim Budil, Lawrence Livermore National Laboratory director, said at the press conference. “We were in a position for a very long time where it never got closer, right? Because we needed this first fundamental step. So we’re in a great position today to begin understanding just what it will take to make that next step.”

Just to start, researchers need to be able to reach ignition once more. “This is one igniting capsule, one time. To realize commercial fusion energy, you have to do many things; you have to be able to produce many, many fusion ignition events per minute,” Budil said. “There are very significant hurdles, not just in the science but in technology.”

One obstacle is that the lasers utilized in future efforts must be much more efficient. The system chosen in this experiment, the National Ignition Facility, is the largest and highest-energy laser in the world– bigger than three football fields. Yet it’s still based on technology from the 1980s. Modern lasers are much more efficient, and future initiatives will attempt to integrate newer technology into experiments.

“This demonstrates it can be done. That threshold being crossed allows them to start working on better lasers, more efficient lasers, on better containment capsules, etc.” Budil stated. “We need the private sector to get in the game. It’s really important that there has been this incredible amount of US public dollars going into this breakthrough, but all of the steps that we’ll take that will be necessary to get this to commercial level will still require public research and private research.”

Originally published by: The Verge