Energy

Energy-positive laser fusion approach heads toward commercialization

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The NIF Target Chamber at Lawrence Livermore National Labs, where a laser-based fusion approach achieved scientific breakeven in December 2022
NIF
The NIF Target Chamber at Lawrence Livermore National Labs, where a laser-based fusion approach achieved scientific breakeven in December 2022
NIF
The Xcimer ignition chamber
Xcimer Energy

With the promise of unlimited energy, Xcimer has raised over US$100 million from investors and the US Department of Energy to develop a high-energy laser system that's intended for use in a practical fusion power plant.

For over 75 years, scientists and engineers have been pursuing the dream of harnessing fusion energy as a practical power source. Though there have been remarkable achievements, the goal has remained elusive. However, the prospect of providing humanity with all the clean energy it could need or want is too big a prize not to pursue.

The primary contender for fusion power is the tokamak, which uses a doughnut-shaped magnetic field to squeeze and heat hydrogen plasma to tremendous pressures and temperatures many times that at the heart of the Sun. These have achieved fusion, which is relatively easy – it can also be done by any hydrogen bomb or lab bench lash up. The tricky bit is to achieve nuclear fusion while getting more energy out than you put in, which is called fusion ignition.

The Xcimer ignition chamber
Xcimer Energy

This was first accomplished on December 5, 2022 by the Lawrence Livermore National Laboratory (LLNL) National Ignition Facility (NIF), which used an alternative to tokamak called laser-driven inertial fusion. This involves focusing of a massive bank of lasers on a small frozen pellet of deuterium and tritium. The sudden blast from these combined beams causes the pellet to implode and set off a fusion reaction that produces more energy than was required to generate it. To date, the NIF can create 2.5 times more fusion energy than the laser energy delivered to ignite the fuel.

At first, this seems like a great breakthrough, and in many ways it is. Unfortunately, the LLNL installation is designed primarily for pure research. Its only practical application is to carry out fusion experiments to assure the safety and reliability of American nuclear warheads. It isn't designed as a way to achieve a practical fusion power plant.

That is where Xcimer Energy comes in. Since 2022, the Denver-based company has been working to turn the laser fusion concept into a practical source of power. The goal is to produce a new krypton-fluoride laser installation that generates 10 times higher laser energy at 10 times higher efficiency and over 30 times lower cost per joule than the NIF.

Using technology first developed for the US Strategic Defense Initiative (nicknamed the Star Wars program) in the 1980s, the Xcimer installation will use a laser system producing over 10 megajoules of energy. This will be focused on larger deuterium/tritium pellets that are easier to make and handle, and produce more energy when ignited.

Producing energy is useless if it isn't harnessed, so the fusion chamber has molten lithium salts flowing through it, not only to protect the wall from neutrons, which reduces maintenance, but to absorb the energy and carry it away to generate power.

The idea is that the lasers will stand at a distance of 164 ft (50 m) and focus their beams through two small holes to reach the target pellet. The system is designed to ignite only a small amount of the fuel, which produces the energy needed to ignite the remainder like a match set to paper. This is more efficient and economical.

"The benefits of fusion for humanity have never been more clear or more necessary," said Mark Cupta, Xcimer board member. "Xcimer has developed a game-changing approach to inertial fusion and assembled a team of the brightest minds in the industry to execute on it. I’m confident that with Xcimer leading us on this path, the world will see this transformative source of energy finally deployed at commercial scale."

Source: Xcimer

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18 comments
paleochocolate
I bet it really isn't net energy positive.
Trylon
And just how are they going to scale up the process to a near-continuous stream of several ignitions per second from the once per day that it is now? What breakthrough have they made in resetting and refueling between ignitions?
Karmudjun
Thanks for the article David. I remember the Lab reports of the successful experiment in 2022. Although they say they achieved an energy positive successful experiment in 2022, Xcimer wants to capitalize on it and scale it up to provide a proof of concept that is even more energy positive than the initial results of 2022? I guess I'll join with paleochocolate and say it isn't so! Because that is what a curmudgeon does! But David, you need to ask yourself - what are the hidden energy costs for a NET energy positive fusion system? Fuel production energy must be calculated, unit site placement and integrity assurance all costs time & money = energy, so when you fire the lasers, do you really get significantly more than all of those energy costs prior to firing the laser?
paul314
The problem with most laser fusion is that the lasers aren't very efficient. Sometimes just a few percent of the power going in comes out as photons. So you need a seriously positive-energy fusion reaction (10-100x the energy going in) to end up net positive. I wish them luck, but I hope their investors aren't playing with money they need.
solas
"The tricky bit is to achieve nuclear fusion while getting more energy out than you put in, which is called fusion ignition." - that should really read: "while *harnessing* more energy out than you put in"
Immortal Melvyn M. Lusterio
We can also create a laser gun disintegrator to avert terrorists or criminals!
Non-Compos_Mentis
__ Re "... temperatures many times that at the heart of the Sun ...: How do we know the temperature at the "heart of the Sun"?
__ Just asking .
Eirhead
Being net energy positive isn't really a big achievement anymore with a deuterium tritium reaction...

But the holy grail in fusion is now igniting a pure He3 reaction. An He3 reaction doesn't leave any leftover neutrons that destroy your generator making it much cleaner and sustainable.

It's a big reason why there's a push to get boots on the moon by several countries now.
Mark T.
NIF is now reporting a highest energy gain of 2.36. So is Xcimer rounding up a bit to 2.5 or do they know something we don't? BTW, NIF is increasing looking like the Hubble Space Telescope in that both were initially flawed, but both eventually improved into a unquestionable successes.
michael_dowling
Why the excitement over fusion? Have these people not heard that climate change is the only issue we should be trying to solve right now? I say built more FISSION plants and continue building out solar and wind generation. When we have totally converted to climate friendly power generation,other projects can get our attention.