Validating the path to fusion ignition

Pacific Fusion is excited to share a peer-reviewed paper on our advanced simulation code for modeling fusion systems —  the first time a private fusion company has rigorously validated its code across all processes for its approach to achieve high fusion gain. It’s one of four papers we’re publishing today in the journal Physics of Plasmas, which together outline the evidence supporting our path to net facility gain — that is, more energy out than all the energy stored in the system — by 2030.

Simulations are a critical tool that help scientists predict how a fusion experiment will unfold, allowing them to effectively design fusion systems. Simulations have been used extensively at the U.S. national labs, where they were central to the National Ignition Facility achieving fusion ignition in 2022. But computer-based simulations aren’t reliable unless they’ve been validated to accurately match the results of real-world experiments. National labs validate their codes incrementally over many years, publishing results from individual experiments. Some private companies use codes validated for only part of the fusion process, and others haven’t published any validation at all. We’ve taken a different approach. 

• In the first paper published today, we detail how we developed world-class simulation tools and validated them against a rigorous set of benchmarks covering the essential phenomena for modeling our approach to fusion at ignition scale. This is the first time a private fusion company has published such a comprehensive validation, spanning everything from hydrodynamic instabilities to fuel compression and confinement, integrated fusion experiments, and code-to-code benchmarks for ignition-scale pulser inertial confinement fusion (ICF) targets. Working with the Flash Center at the University of Rochester, we advanced a customized version of a code called FLASH to model targets for pulsed-power systems like our Demonstration System, then rigorously validated it against six benchmarks (*see below) to confirm its accuracy.
• In the second paper, we applied the validated simulation code to inform the design of pulser-driven inertial confinement fusion (ICF) systems, including our Demonstration System. We analyzed a pulser-driven ICF approach pioneered on Sandia National Laboratories’ Z Machine, which pre-heats and pre-magnetizes a fusion target by using external lasers and magnets. Our simulations helped us accurately understand the behavior of fusion targets in this design. 

The tools and knowledge are now letting us design simpler, more effective targets for achieving net facility gain — including designs that eliminate the need for external hardware for pre-heat and pre-magnetization.

By sharing our results openly and subjecting them to rigorous peer review, we’re hoping that others in the private fusion sector, across all approaches, will publish their own validation studies. Doing so can help set a higher standard of rigor, build trust, and strengthen the credibility of the field.

Our third paper lays out our detailed path to building a first-of-a-kind inertial fusion system that meets our AMPS criteria — affordable, manageable, practical, and scalable — while achieving record-breaking performance. 

As we shared in April, this paper lays out how our Demonstration System will achieve 100× higher facility gain and be 10× less costly than the only fusion system so far to achieve ignition — the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, which reached that milestone in 2022. That’s a 1,000-fold leap in practical performance.

Our fourth paper, co-authored with leading scientists from national labs and universities, is a perspective that makes the case for the architecture underpinning our pulser-driven ICF system for commercial fusion energy. The paper argues that pulser-driven ICF is the most promising path to commercial fusion energy, with experimentally demonstrated performance comparable to laser-driven ICF and tokamak systems, despite having received only a fraction of the funding.

Following this roadmap, Pacific Fusion is now working to build efficient and empirically-supported systems for fusion ignition – and eventually commercial power. 

Want to build with us? We are hiring.

*Benchmarks include:

• Three experimental studies on the Z Machine measuring key processes influencing ICF target design such as magneto-Rayleigh Taylor and Richtmyer-Meshkov. We show that FLASH accurately captures these hydrodynamic phenomena, agreeing with both experimental data and physics theory.
• A high-performing MagLIF experiment on the Z Machine known as Z2977, which carefully measured fusion performance in the target such as the number of fusion reactions that occurred and the temperature obtained in the fusion fuel. The FLASH calculation agrees with the experimental measurements to the same degree of accuracy as the national lab code used to design the target for the experiment.
• An important theoretical and simulation study by Daniel Ruiz, Paul Schmit, and others at Sandia National Laboratories (Paul Schmit is now at Pacific Fusion) that scales a MagLIF target from what has been achieved experimentally on Z today to prospective higher current facilities, up to 60 MA, which we plan to achieve with our Demonstration System. At high currents, the theory and published simulations show the MagLIF targets achieve ignition; this behavior is also captured in FLASH, and we find good agreement with the national laboratory code HYDRA, which is the main ICF target design code used at NIF.