EMC2 has been advancing Polywell fusion technology for over 30 years, building on the original ideas from Dr. Robert Bussard (Bussard, US Patent 4826646A, 1989). Over the decades, we have explored various embodiments of the Polywell technology, achieving many successes. Some approaches were abandoned due to limited progress and/or significant shortcomings. However, EMC2 continues to focus its R&D efforts on the most promising Polywell embodiments that offer significant advantages for both near-term applications and long-term fusion energy generation.
In recent years, EMC2 has encountered criticisms from parts of the fusion community regarding the Polywell approach. Manyof these critiques, along with efforts from several imitators, have focused on earlier, abandoned embodiments of the technology. EMC2 has endeavoured to steer the community toward EMC2’s most successful R&D directions. We have shared updates on progress in addressing key scientific challenges through public lectures, such as our online presentation (Microsoft Tech Talk),as well as through peer-reviewed publications (Physical Review X, Frontiers in Astronomy and Space Sciences). As these efforts have not fully dispelled misconceptions, we are now taking further steps, including launching the FAQ (Frequently Asked Question) below to address these critiques more directly.
The critiques by Rider and Nevins focused on an earlier version of the Polywell approach that relied on non-Maxwellian plasma conditions and spherical beamfocusing. While their analysis, though not exhaustive, raised valid points, it does not apply to the current direction of EMC2’s Polywell research.
EMC2’s current approach focuses on achieving a high-beta plasma state within the Polywell cusp configuration to generate fusion using deuterium-tritium (D-T) fuels, rather than relying on non-Maxwellian, spherically converging beams. This approach aligns with Dr.Bussard’s original 1989 patent, which emphasized the importance of a high-beta magnetic cusp configuration (as illustrated in Figures 1A, 1B, and 1C of the patent) as a key feature of Polywell fusion. In this configuration, the reactor operates with high plasma density, eliminating the need for spherical beam focusing to enhance fusion reactivity. The expected plasma density in a high-beta Polywell fusion reactor is approximately 1e20/m³, comparable to that of the ITER tokamak reactor and about a million times higher than conventional Inertial Electrostatic Confinement (IEC) fusion devices.
Since 2014, EMC2 has focused on using conventional D-T fusion fuels, which do not require non-Maxwellian plasma conditions to achieve fusion, as presented in our online presentation. However, operating a fusion reactor under non-Maxwellian conditions—with a high ion temperature (e.g., 200 keV) and a lower electron temperature (e.g., 20keV)—could offer significant advantages when using advanced fuels such as proton-boron-11 (p-B11). In such cases, the concerns raised by Rider and Nevins would need to be addressed, and EMC2 plans to dedicate resources to this after successfully developing a Polywell fusion reactor based on D-T fuels.
Similar to the critiques in Myth #1, the academic papers questioning the Polywell approach are based on outdated versions of the technology. None of these papers specifically examine the high-beta plasma conditions inside the Polywell cusp, where plasma stability is maintained by the favorable curvature of magnetic field lines. The same applies to private companies that failed to achieve critical high-beta conditions in their attempts to develop Polywell fusion. For EMC2, these outcomes are not unexpected, as it took many years of R&D to reach the critical high-beta plasma state in 2013, requiring approximately 700MW of pulse power.
EMC2 has since made significant progress in understanding and refining the production and utilization of high-beta plasma conditions within the Polywell cusp. This progress has been accelerated through the use of high-performance computing (HPC) infrastructure and a state-of-the-art plasma simulation code. An animation showcasing the results of our full 3D first-principles simulation is available on our website, demonstrating this breakthrough.
It’s important to recognize that fusion research is an ongoing process, with meaningful breakthroughs often taking decades of persistent efforts. EMC2 remains confident in its approach and plans to accelerate our progress toward developing a functional Polywell fusion device by leveraging our recently acquired capabilities in advanced plasma simulations.
If EMC2 were a public research institution, the lack of full disclosure might reasonably be seen as a sign of unsuccessful R&D. However, EMC2 is a private enterprise with shareholders, investors, and employees to protect. As such, we must safeguard our intellectual property (IP) to ensure our success and survival. EMC2 carefully balances what information to disclose, even under non-disclosure agreements (NDA), and what proprietary data and codes must remain confidential. We trust that the public understands our need to protect this IP.
Nevertheless, EMC2 is committed to being a responsible corporate citizen by sharing progress in basic scientific research. Over the years, we have delivered more than a dozen lectures and seminars at universities and public research institutes and published peer-reviewed papers. EMC2 will continue to share updates on our advancements when appropriate.
This is not true. The Navy-supported effort significantly advanced the Polywell technology throughout the program's existence as evidenced by reviews of the work conducted periodically by a panel of fusion science experts that answered directly to the Navy program manager. These reviews all reported solid progress and recommended continued work.
Changes in strategic direction and competing priorities within the Navy's fixed Science and Technology budget led to the decision to discontinue the support for EMC2 R&D. EMC2 can provide additional information to support this statement as needed.