Nuclear Fusion Lab Achieves ‘Ignition’: What Does It Mean?

The scientists at the world's largest nuclear-fusion facility created a nuclear reaction that generated more energy than they used. The fusion- research community was excited by the results of the breakthrough at the US National Ignition Facility. Nuclear fusion can be harnessed to provide a source of clean energy.

Mark Herrmann is the deputy director for fundamental weapons physics at Lawrence Livermore National Laboratory. The landmark experiment is the culmination of many years of work by multiple teams on everything from lasers to targets and computer models. It's what we are celebrating.

The flagship experimental facility of the US Department of Energy's nuclear-weapons programme that was designed to study reactions created by such weapons has faced criticism for delays and cost overruns. In August 2021, NIF scientists announced that they had used their high-powered laser device to achieve a record reaction that crossed a critical threshold on the path to ignition, but attempts to replicate that experiment in the following months fell short. The effort that paid off last week was the effort to rethink the experimental design.

Michael Campbell, former director of the fusion laboratory at the University of Rochester in New York and an early proponent of NIF, says that a lot of people didn't think it could be done. I'm having a celebration.

The latest experiment by NIF is looked at by Nature.

What did NIF achieve?

A set of 192 lasers was used by the facility to deliver 2.05 megajoules of energy to a small gold cylinder. The pulse of energy caused the capsule to collapse, creating temperatures only seen in stars and thermonuclear weapons, and the hydrogen isotope fusion into helium, releasing additional energy and creating a cascade of fusion reactions. The amount of energy that was released was more than double the previous record, according to the laboratory.

This is the first time in the history of fusion that it has produced more energy than it consumes.

ignition is a benchmark measure for fusion reactions that looks at how much energy went into the target compared to how much energy was released. NIF's 192 lasers consumed 322 megajoules of energy in the fusion reactions.

Dave Hammer is a nuclear engineer at Cornell University in New York.

The path to laser fusion energy is a long one. It was not designed to be efficient. It was supposed to be the biggest laser we could build to give us the data we need.

NIF scientists made a number of changes before the latest laser shot in order to achieve ignition. In order to create a more spherical implosion, scientists created a new target with less imperfections and adjusted how the laser energy was delivered onto the target. Changes that are small can make a big difference when it comes to fusion.

Why are these results significant?

The result is a milestone in fusion science because it is about proving what is possible. The facility was designed to help nuclear-weapons scientists to study the intense heat and pressures that occur inside thermonuclear explosions if the facility produces high-yield fusion reactions.

Stephen Bodner is a physicist who used to head the laser-fusion programme at the US Naval Research Laboratory. The big question now is what the Department of Energy will do next, double down on weapons research at NIF or pivot to a laser programme that is specifically geared towards fusion-energy research.

What does this mean for fusion energy?

The latest results have renewed interest in a future powered by fusion energy, but experts warn that there is a long way to go.

Many researchers doubt that laser-driven fusion will be the approach that ultimately yields fusion energy, as the facility was not designed with that in mind. Campbell believes that the success could lead to a new programme focused on energy applications. He says it's necessary to have credibility to sell energy programmes.

The achievement was described as a proof of concept. She didn't want to give you a sense that the NIF would be plugged into the grid. This is the foundation of a fusion power scheme.

There are many fusion experiments around the world that are trying to achieve fusion. The design and construction of plants that can extract the heat produced by the fusion and use it to generate significant amounts of energy that can be turned into usable electricity remains a challenge.

Tony Roulstone, a nuclear-energy researcher at the University of Cambridge, UK, said that the result is still a long way from the actual energy gain required for the production of electricity.

Anne White is a plasma physicist at the Massachusetts Institute of Technology in Cambridge.

What are the next major milestones in fusion?

To demonstrate that fusion can be a viable method of generating energy, the efficiency of the yield needs to grow by at least two orders of magnitude.

Time Luce, head of science and operation at the international nuclear-fusion project ITER, said that researchers will need to increase the rate at which the lasers can produce the pulse and how quickly they can clear the target chamber to prepare it for another burn.

White says thatSufficient fusion energy- producing events at repeated performance would be a big milestone.

The US$22 billion ITER project is a collaboration between China, the European Union, India, Japan, Korea, Russia and the United States. ITER will keep the deuterium and tritium confined in a vacuum chamber and heat it up until the nucleus fusions. When it starts doing so, it will aim to reach the stage where the self- heating power is the main source of heating. It is possible to produce more energy than what is put into it.

What does it mean for other fusion experiments?

There are many fusion technology concepts being pursued by governments. Tokamaks and stellarators use magnetic confinement, as well as a hybrid of the two, among other approaches.

According to White, the technology required to make electricity from fusion isn't related to the concept.

Engineering challenges at ITER and other facilities are not the same as those faced by NIF. The symbolic achievement could have a large effect. It should have a positive impact on fusion research as a result of this result.

The article was published on December 13th, 2022.