Xcimer Energy Completes First Private-Sector Electron-Beam Excimer Laser

Denver-based inertial fusion company’s electron-beam excimer laser is also the first of its kind built by any organization in more than 20 years; in May, it achieved the longest pulse length of any KrF laser

• Xcimer Energy announced today the completion and operation of the world’s first electron-beam-pumped excimer laser built in the private sector—and the first of its kind built by any organization in more than 20 years.
• The system operates at the longest pulse length of any Krypton-Fluoride laser; in May, the laser achieved a record pulse length of 3 microseconds.
• Completion and operation of this system — known as the Long Pulse Kinetics (LPK) platform — represents the first technical target in Xcimer’s roadmap for the U.S. Department of Energy’s Milestone-Based Fusion Development Program, submitted three months ahead of schedule.
• As the global race to commercialize fusion accelerates, Xcimer has raised more than $120 million from leading energy investors and the U.S. government to develop a scalable pathway to fusion power.

Xcimer Energy Inc. announced today that the inertial fusion startup has completed the world’s first electron-beam-pumped excimer laser funded by the private sector.

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Photo credit: Edward DeCroce

Xcimer’s electron-beam laser is also the first built by any organization, including federal labs, in more than 20 years. The system operates at the longest pulse length of any Krypton Fluoride (KrF) laser. In May, the laser achieved a pulse length of 3 microseconds – a global record for this type of laser.

Xcimer’s Long Pulse Kinetics (LPK) platform is the first key element of its prototype laser system, code-named Phoenix, which is on track to be completed in 2026. The LPK collects data that proves the viability of Xcimer’s technology and informs future design of its lasers that will power inertial fusion energy systems.

Xcimer submitted a report on its LPK system to the U.S. Department of Energy’s Milestone-Based Fusion Development Program, three months ahead of schedule. Completion and operation of the LPK represents Xcimer’s first major technical milestone in the program. The Fusion Development Program is modeled in part after the NASA Commercial Orbital Transportation Services (COTS) program, which unleashed private companies to meet early technical milestones on the way to building today’s commercial space-launch industry.

“We’ve already begun using Xcimer’s LPK experimental testbed to validate laser models and inform the design of our future systems,” said Conner Galloway, CEO and Chief Science Officer of Xcimer. “This milestone also sends the strongest signal yet that the private sector can build on decades of public investment to turn transformative research into commercially viable systems. We’ve seen this transition before in industries like space—and we’re beginning to see it happen in fusion.”

Next up: Vulcan

Xcimer’s goal for 2030 is to complete the construction of Vulcan, its next-generation facility that will achieve the highest laser energy in the world using the largest laser amplifiers ever built which will be designed based on data from LPK. Xcimer’s roadmap includes putting the first inertial fusion power plants delivering electricity to the grid as soon as the mid-2030s.

Xcimer is already taking proposals on prospective new sites nationwide to house Vulcan, which would directly employ hundreds of people in a large variety of jobs, including physicists, technicians, and support staff. Vulcan’s location could pave the way for a future regional source of zero-carbon energy expertise, making the location attractive to more emerging businesses such as artificial intelligence and software companies, robotics manufacturers, and medical research facilities. Xcimer expects to narrow the field of prospective sites by the end of 2025.

“Nearly 100 people on our team should take a moment to appreciate the completion of LPK,” said Alexander Valys, Chief Technology Officer of Xcimer. “But only for a moment – because LPK is the smallest laser we will ever build, and we have an exciting journey ahead.”

Utilities and communities across the country are actively partnering to craft competitive proposals, aiming to win this once-in-a-generation project. Vulcan’s presence is expected to spark a powerful economic ripple effect, driving infrastructure investment, workforce development, and attracting cutting-edge industries.

Fusion: The energy of the sun and stars

Fusion energy occurs when light atoms fuse into heavy atoms, releasing energy in the process. The same process powers the sun to deliver massive amounts of energy with zero carbon emissions and no accident risk. Through this process a single gram of hydrogen isotopes yields the same energy as 11 metric tons of coal.

Fusion is a clean and essentially limitless source of power — the last new energy source humanity will ever need. It will unlock new industries and help fusion-forward countries chart the most prosperous path into the future.

Xcimer is developing what some experts say is the most economically viable path to delivering virtually limitless, carbon-free energy, adapting the only fusion approach that has been experimentally demonstrated to exceed scientific breakeven.

This breakthrough has the potential to power energy-intensive technologies across sectors including AI, robotics, healthcare, transportation, desalination, manufacturing, and space exploration.

Xcimer is pioneering the use of high-powered excimer lasers to create an intense pulse of light, focused onto a sphere of fuel the size of a pea, creating extremely high temperature and pressure that initiates fusion reactions. The fusion energy from each burning capsule is captured by a waterfall of molten salt inside the chamber. This carries away the heat to generate steam, which in turn drives turbines to produce electricity through a standard process.

Compared to other fusion companies, Xcimer says it has superior long-term economics due to the decoupled nature of the subsystems, higher fuel burnup fraction, and ability to directly protect the first structural wall with the molten salt flow so that it can last the entire lifetime of a power plant.

The global race heats up

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory made history in 2022 by achieving fusion ignition for the first time, after six decades of scientific research in the field. NIF’s achievement marked “scientific breakeven,” when the energy produced by a fusion reaction equals or exceeds the energy used to ignite the fusion fuel.

Founded a year prior to the NIF breakthrough in California, Xcimer is building a laser architecture that will affordably produce up to 10 times more laser energy at 10 times higher efficiency than the NIF system while bypassing the optics damage issues inherent in NIF-like architectures. While excimer lasers are widely used in semiconductor lithography, medical and industrial applications, Xcimer will be the first company to apply them to fusion energy generation at scale.

Xcimer has raised just over $111 million from leading energy investors since its founding in 2022. It’s part of the DOE Milestone-Based Fusion Development Program, a highly competitive public-private partnership program designed to accelerate the development of fusion energy on the power grid. Xcimer was awarded $9 million, one of the most significant awards under the program’s first budget period.

Xcimer also collaborates with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Savannah River National Laboratory, Naval Research Laboratory, Laboratory for Laser Energetics, Massachusetts Institute of Technology, General Atomics and Westinghouse.

A global race to develop fusion energy has begun — particularly in the United Kingdom (which allocated about $530 million for fusion research at the UK Atomic Energy Authority); Germany (whose new government wants the first fusion power plant in Germany); and Japan (which considers fusion an essential part of its 2050 vision). In 2023, China earmarked at least $1.5 billion to fusion – and investments in Chinese fusion companies have surged from zero in 2021 to $1.3 billion in 2024, according to the Fusion Energy Base.

At scale, the industry could employ tens of thousands of people in each country where plants are built and located, and support a robust supply chain. Fusion’s return on the government investment to the American taxpayer could be gigantic, starting with tax revenue from a $3 trillion global energy business, according to an International Energy Agency estimate.

For photos and additional details, please visit this LPK blog post and our media site.

About Xcimer Energy Inc.

Xcimer is an inertial fusion company combining novel laser technology with proven science to achieve commercial deployment of fusion energy. Its approach to inertial fusion holds the best prospect for long-term economic viability. Founded in 2022 and based in Denver, Colorado, Xcimer is backed by the world’s leading climate tech investors and has been selected for funding by the U.S. Department of Energy. Its mission is to develop a source of unlimited, clean, safe and reliable energy to power the future. To learn more, visit https://xcimer.energy/.

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Xcimer has completed the world’s first electron-beam-pumped excimer laser funded by the private sector. It is also the first built by any organization, including federal labs, in more than 20 years.