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Fusion startup Xcimer Energy, backed by its $100 million Series A, has started operating a first-of-a-kind novel laser at its headquarters in Denver (and Axios exclusively fired it on Monday). 

Why it matters: Companies, investors and governments are racing to try to commercialize fusion tech as a limitless form of clean energy. 

Zoom in: The laser, called the Long Pulse Kinetics (or LPK) test bed, is the first private sector-funded laser of its kind.

About the size of a medium shipping container, the laser is housed inside a concrete enclosure to protect workers from the X-rays it produces when fired (roughly one dental X-ray's worth).

Co-founders Alexander Valys and Conner Galloway say it took only four months to build LPK, which is an intricate design of metal gas-filled chambers, vacuum pumps, and two Marx generators sitting in transformer oil. 

The data that Xcimer gets from LPK will inform the design of bigger, more powerful lasers — including Vulcan, which would be the world's largest laser. "This [LPK] is the smallest laser we'll ever build," says Valys. 

How it works: Xcimer is using a form of ultraviolet gas laser called an excimer laser, which is already used by sectors like semiconductor manufacturing.

The lasers can produce longer pulses, leading to lower-power, less expensive systems.

Xcimer ultimately will use its lasers to compress nuclear fuel and kick off a fusion reaction. The idea is to make the lasers cheap enough to enable fusion to be commercial.

Laser-based fusion, called inertial fusion, was first demonstrated at the lab scale back in the 1980s by the U.S. government using X-rays from underground nuclear tests. In 2022, the National Ignition Facility achieved fusion ignition and breakeven using an inertial fusion design.

Inside the control room of Xcimer's first laser built for fusion

Inside the control room of Xcimer's first laser, which will provide data for the world's largest laser. Photo: Courtesy of Xcimer

Behind the scenes: In a control tent outside of the enclosure, Axios clicked a button on a computer screen to charge the laser system and then another button to hit the fire button.

The laser system produced an audible clunk sound, the noise of the energy flooding into the gas, followed by the beeping of the X-ray detector.

The diagnostics screen showed the corresponding voltage and current that the electron beam had indeed fired.

Follow the money: Xcimer says it plans to use most of its Series A funding, raised last year, on the laser system that includes LPK, while Vulcan could cost around $1 billion to build. 

Company investors include Hedosophia, Breakthrough Energy Ventures, Lowercarbon Capital, Prelude Ventures, Emerson Collective, Gigascale Capital and Starlight Ventures.

The DOE has also awarded the company a $9 million award, and developing LPK was the first milestone for the program. 

What's next: Xcimer hopes to select a site for Vulcan later this year. 

It aims to demonstrate breakeven fusion — when the reaction produces more energy than it consumes — by 2030.

Exclusive: Xcimer hits major laser fusion milestone

It's the first laser of its kind funded by the private sector.

A novel laser built by fusion startup Xcimer and funded by VCs.

Xcimer's laser, the Long Pulse Kinetics (or LPK) testbed,  is the first electron-beam-pumped excimer laser funded by the private sector. Photo: Courtesy of Xcimer

Fusion startup Xcimer Energy, backed by its <a class="gtmContentClick" data-vars-link-text="$100 million Series A" data-vars-click-url="https://www.axios.com/pro/climate-deals/2024/06/04/fusion-xcimer-raises-100m" data-vars-content-id="8d079ef0-389a-4b7b-8aec-952f065d2343" data-vars-headline="Exclusive: Xcimer hits major laser fusion milestone" data-vars-event-category="story" data-vars-sub-category="story" data-vars-item="in_content_link" href="https://www.axios.com/pro/climate-deals/2024/06/04/fusion-xcimer-raises-100m" target="_self">$100 million Series A</a>, has started operating a first-of-a-kind novel laser at its headquarters in Denver (and Axios exclusively fired it on Monday). Why it matters: Companies, investors and governments are racing to try to commercialize fusion tech as a limitless form of clean energy.

Exclusive: Xcimer hits major laser fusion milestone

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