California-based start-up Pacific Fusion has reported results from Sandia National Laboratories (SNL) showing a simplified target design that eliminates the need for expensive external magnetic coils, potentially lowering reactor costs. The experiments were conducted at SNL’s Z Pulsed Power Facility under a Cooperative Research & Development Agreement.
Using Sandia’s Z machine – the world’s most powerful pulsed-power facility – the researchers gathered measurements on a simplified target design, made only of aluminium and plastic, that can potentially be used as the basis for pulser-driven inertial confinement fusion (ICF). The measurements provide data to help evaluate and refine target designs in this area of research.
Pacific Fusion was founded in 2023 to leverage breakthroughs in inertial fusion achieved at US National Laboratories in 2022. Its technical approach combines the laser-driven ignition success of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) with the pulsed power engineering of SNL’s Z Machine.
The company is focused on commercialising pulsed magnetic inertial fusion. It utilises a modular pulser architecture. Instead of using massive lasers, “bricks” (capacitors and switches) are assembled into shipping-container-sized modules to deliver high-current pulses that magnetically compress fusion fuel. The company is currently transitioning from theoretical design to large-scale infrastructure and experimental validation. It is targeting “net facility gain” (producing more energy than the system consumes) with a full-scale demonstration system by 2030.
Founders include Eric Lander (CEO), former leader of the Human Genome Project and a former White House science adviser; Will Regan (President), a former fellow at the Department of Energy’s (DOE’s) Advanced Research Projects Agency-Energy (ARPA-E) and project lead at Alphabet’s X; and Keith LeChien (CTO), former Director of Inertial Confinement Fusion at the National Nuclear Security Administration (NNSA) and pulsed power expert.
The company emerged from stealth mode in late 2024 with a Series A funding round of $900m led by General Catalyst, with participation from high-profile backers such as Bill Gates and Eric Schmidt. The funding is milestone-based, unlocking capital as specific technical goals are met.
ICF uses fast pulses of energy to implode small targets containing fusion fuel, causing them to release massive amounts of energy on each shot. In 2022, the NIF reported the first experiment to achieve fusion “ignition”. A significant barrier to deploying ICF for commercial fusion energy production has been that the target and any surrounding material are vaporised on each shot and need to be replaced. Replacing targets and associated components between experiments is an engineering and cost challenge, motivating research into simpler designs.
In the latest experiments at SNL, the team measured how magnetic fields diffused through a simplified target design intended to support pre-magnetisation concepts. The simple target, made of just plastic wrapped in aluminium, allows the magnetic field to diffuse into the target to “pre-magnetise” the fusion fuel. Pre-magnetisation is desirable for pulser-driven inertial fusion because it helps trap heat in the fusion fuel, allowing it to more easily ignite.
During four tests at the Z machine, researchers delivered a 22-million-amp pulse in just 120 nanoseconds. Magnetic sensors embedded in the targets measured how the magnetic field moved through the material, confirming that the magnetic diffusion design works as intended.
Two versions of the target were tested, both small metal cylinders about the size of a pencil eraser but with different aluminium thicknesses. The experiments showed that the thinner aluminium layer allowed the magnetic field to enter the target more quickly and strongly, providing the team with a new lever for refining performance.
“These findings show that the target can now do what previously required large, single-use magnetic coils, dramatically simplifying the fusion system,” said Chief Technology Officer Keith LeChien. “By eliminating expensive and impractical external hardware, we now have confidence to design a new class of inexpensive targets that enables us to reach high-gain fusion and carve a path toward economically viable fusion power. We’re grateful to our collaborators at Sandia for their partnership and for the opportunity to test these concepts at the Z Facility.”
The results also enable validation of Pacific Fusion’s advanced simulation tools, developed in collaboration with the Flash Centre at the University of Rochester. The code’s predictions for target behaviour will be improved by the experimental data, enabling future designs of fusion targets.
“These experiments are a good example of collaboration between the national labs and industry for research that is a dual benefit for Pacific Fusion and Sandia,” said Greg Rochau, Director of Sandia’s Pulsed Power Sciences. “Z is presently the only facility providing these unique pulsed-power capabilities that support a broad range of high-energy-density physics and fusion-related research. Results like these help strengthen the scientific foundation Sandia applies to its national security mission.”
The work directly informs the design of Pacific Fusion’s planned Demonstration System, which will be built in New Mexico and is aimed at achieving net facility gain by 2030. In late 2025, the company announced a $1bn investment to build a research and manufacturing campus in Albuquerque, New Mexico. A manufacturing “build centre” in Los Lunas, New Mexico opened in December 2025 to produce components for the larger campus. The collaboration between Sandia and Pacific Fusion aligns with DOE’s Fusion Science and Technology Roadmap released in October 2025.
