Pulsed-fusion pioneer and CEO of Helion Energy — pursuing a field-reversed configuration approach with direct energy conversion to deliver fusion electricity on a commercial timeline.
David Kirtley developed an interest in plasma physics and pulsed-power systems early in his academic career. He studied at the University of Michigan, where he earned his doctorate in nuclear engineering and radiological sciences. His graduate research focused on magneto-inertial fusion and pulsed plasma systems, building expertise in the physics of compressing magnetized plasmas to fusion conditions.[1]
During his time at Michigan, Kirtley worked on experiments involving the rapid compression of field-reversed configurations (FRCs) — self-organized plasma structures that can be translated, merged, and compressed. This work laid the scientific foundation for the approach he would later commercialize at Helion Energy.
Kirtley co-founded Helion Energy, based in Everett, Washington, to develop a pulsed fusion system capable of generating net electricity. The company's approach centers on forming two FRC plasmoids, accelerating them to high velocity, and colliding them inside a compression chamber. The merged plasmoid is then compressed by an external magnetic field to reach fusion temperatures and densities.[2]
What distinguishes Helion's concept is its emphasis on direct energy conversion. Rather than using fusion heat to boil water and drive turbines, the system is designed to recapture energy from the expanding plasma electromagnetically — converting the kinetic energy of charged fusion products directly into electricity through the same magnetic coils that performed the compression.
Helion has built and operated a series of increasingly capable prototype devices. The company's sixth prototype, dubbed Trenta, achieved plasma temperatures exceeding 100 million degrees Celsius and demonstrated the viability of the FRC merging and compression cycle at scale. Helion announced that its seventh prototype, Polaris, would target net electricity production.[2]
Helion's fuel cycle aims to use deuterium and helium-3 (D-He3) as the primary fusion reaction in its commercial system, though early prototypes operate with deuterium-deuterium (D-D) reactions. The D-He3 reaction produces charged particles rather than neutrons, which is advantageous for direct energy conversion and reduces neutron-induced material damage.
As CEO, Kirtley has led Helion through multiple rounds of private funding totaling over $570 million, including a $500 million Series E round in 2021 with an additional $1.7 billion of committed funding. The company has attracted backing from prominent technology investors, reflecting Kirtley's ability to translate complex plasma physics into a compelling commercial narrative.[3]
Kirtley has advocated for a rapid, iterative engineering approach to fusion development, drawing parallels to the aerospace industry's test-fly-fix methodology. Under his leadership, Helion has maintained one of the faster prototype iteration cycles in the private fusion sector, completing multiple full-scale builds within a decade.
His work has contributed to broader recognition that pulsed, non-tokamak approaches represent viable pathways to fusion energy, expanding the conceptual landscape beyond the mainline tokamak and laser-driven inertial confinement programs that historically dominated government-funded research.