Pacific Fusion has found a cheaper way to power its fusion reactor

The biggest question about fusion power remains unanswered: How can you be sure that the cost of starting a fusion reaction is not higher than the price you can sell the energy for?

A lot of people have ideas, but no one has solved them yet. For example, Commonwealth Fusion Systems is confident enough to build a massive reactor that will cost hundreds of millions of dollars. But the device won’t be operational until next year, leaving the question unanswered for now.

Other recently founded companies believe they have a chance to build a fusion power plant at a lower cost, including Pacific Fusion. Today the company announced results from a series of experiments it conducted at Sandia National Laboratories that it says will eliminate some of the costly parts of its approach. The company shared the results exclusively with TechCrunch.

Fusion power promises to generate large amounts of electricity 24/7 and deliver it in a way familiar to today’s grid operators. Most nuclear fusion startups target the early to mid-2030s to operate their first commercial nuclear fusion power plant.

Pacific Fusion follows an approach known as pulse-based inertial confinement fusion (ICF). In essence, they are similar to experiments conducted at the National Ignition Facility (NIF). The company compresses small fuel pellets in rapid succession, and this pressure causes the atoms inside the fuel to fuse and release energy.

But while NIF uses lasers to initiate compression, Pacific Fusion wants to use massive pulses of electricity. These pulses will create a magnetic field surrounding the fuel pellet — roughly the size of a pencil eraser — causing it to compress in less than 100 billionths of a second.

“The faster you can blow it up, the hotter it gets,” Keith Leshin, co-founder and CTO of Pacific Fusion, told TechCrunch.

One of the challenges with pulse-based ICF is that the process usually needs little start-up to work properly. To create conditions in the fuel pellet hot enough for fusion, the researchers used both lasers and magnets to prewarm it. “It’s just a small amount of energy just to give it a little boost before you compress it,” in the range of 5% to 10% of the total energy, Litchin said.

But added lasers and magnets add complexity, cost and maintenance requirements to the machine, making it more difficult to sell power at competitive prices.

So, in experiments at Sandia, Pacific Fusion modified the design of the cylinder encasing the fuel pellet and modified the electrical current delivered to it. Before the large pulse of electricity that ignites the fusion reaction, the company allowed part of the magnetic field to seep into the fuel before compressing it, heating it in the process.

“We can make very subtle changes to how this cylinder is manufactured, allowing the magnetic field to seep or seep into the fuel before it is compressed,” Litchin said.

Pacific Fusion fuel is loaded into an aluminum-coated plastic target. By changing the thickness of the aluminum, the company can adjust the amount of magnetic field that reaches the fuel. The casing needs to be manufactured with some precision, but nothing crazy, LeChien said, which is in line with what’s needed to casing a .22-caliber bullet. “It’s a process that’s been honed, crafted and perfected over more than 100 years,” he added.

The modifications do not significantly change the amount of energy Pacific Fusion needs to deliver to the target. “It doesn’t take a lot of energy to allow this magnetic field to enter the fuel core,” he said. “It’s a very small fraction, much less than 1%. It’s a very, very, very small fraction of the total energy in the system, so it’s virtually unnoticeable.”

Eliminating the magnetic system would simplify the system and its maintenance requirements, which would have a modest impact on the overall cost, he said. But eliminating the laser would cut costs significantly. Laser size [needed] Preheating for these types of systems at high gain is north of $100 million.

Such experiments also help improve the company’s simulations to ensure they match what happens in the real world, LeChien said. “A lot of people have simulated things and said, ‘Oh, this will work or that will work,'” he said. “It’s a completely different game, where you simulate something, build it, test it, and run it. It’s hard to close that loop.”