Why fusion ignition is being hailed as a major breakthrough in fusion — a nuclear physicist explains

The Conversation contributed the article to Space.com's expert voices.

Carolyn Kuranz is an associate professor of nuclear engineering at the University of Michigan.

American scientists have made a major breakthrough in their quest to create energy from nuclear fusion.

Scientists at the U.S. Department of Energy have succeeded in getting more energy out of the process than they had to put in.

RECOMMENDED VIDEOS FOR YOU...

What is the significance of the development? Carolyn Kuranz is an associate professor of nuclear engineering at the University of Michigan who has worked at the facility that just broke the fusion record.

Nuclear fusion breakthrough is related to space exploration.

What happened in the fusion chamber?

A fusion is a nuclear reaction in which two atoms are combined to form one or more new atoms. The energy in the difference in mass is equal to the speed of light. The amount of energy produced by just a tiny amount of mass being converted into energy is similar to what happens in fusion.

For the first time, researchers at the U.S. government's National Ignition Facility have shown what is known as "fusion ignition." When a fusion reaction produces more energy than is being put into the reaction from an outside source, it's called "ignition".

The technique used at the National Ignition Facility involved shooting 192 lasers at a pellet of fuel made of deuterium and tritium placed in a gold canister. The X-rays produced when the lasers hit the canister are about 100 times hotter than the surface of the sun. The fuel will release energy if you can keep these conditions for a long time.

Within a few billionths of a second, the fuel and canister are destroyed. Researchers hope their equipment can survive the heat and accurately measure the fusion reaction's energy.

So what did they accomplish?

Physicists look at the amount of energy released from fusion and the amount of energy within the lasers in order to assess the experiment's success. The ratio is called gain

The fusion process releases more energy than the lasers deliver.

The National Ignition Facility shot a pellet of fuel with 2 million joules of laser energy, which is about the amount of power it takes to run a hair dryer for 15 minutes. The fusion reaction released 3 million joules. The previous record of a gain of 0.7 was achieved in August 2021.

How big a deal is this result?

For the past 50 years, fusion energy has been the "holy grail" of energy production. There is still a long way to go before fusion is a viable energy source, despite a gain of 1.5.

The fusion yield of 3 million joules was less than the laser energy of 2 million joules. It will take a lot of work to improve the efficiency to the point where fusion can provide a net positive energy return when considering the entire end-to-end system.

What needs to be improved?

Scientists have been working on a number of pieces of the fusion puzzle for decades and further work can make this process more efficient.

The first laser was invented in 1960. The most powerful laser facility in the world was built by the U.S. government in 2009. It is 50 times more powerful than the next most powerful laser on Earth. The efficiency of the system could be improved by more powerful lasers and less energy intensive ways to make them.

If there is a small imperfection in the capsule or fuel it can increase the energy requirement and decrease efficiency. A lot of progress has been made to transfer energy from the laser to the canister and the X-ray radiation from the canister to the fuel capsule.

One part of the fuel, deuterium, is abundant in the sea, but the other part, tritium, is very rare. Researchers are hoping to develop a way to harvest tritium directly from fusion. There are other ways to produce fuel in the future.

There are hurdles that need to be overcome before fusion can produce electricity. The cost of a fusion power plant needs to be brought down from the National Ignition Facility. Investments from the federal government and private industry will be required.

There is a global race around fusion with many other labs around the world trying different techniques. For the first time, the world has seen proof that the dream of fusion is possible.

Under a Creative Commons license, this article is re-posted. The article is open in a new tab.

Become a part of the discussion and follow all of the Expert Voices issues and debates on social media. The author's views do not represent those of the publisher.