Senior Experimental Scientist

Helion•Everett, WA

4d•Onsite

About The Position

We are a fusion power company based in Everett, WA, with the mission to build the world's first fusion power plant, enabling a future with unlimited clean electricity. Our vision is a world with clean, reliable, and affordable energy for everyone. Since Helion's founding in 2013, we have raised over $1 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors SoftBank and Lightspeed to propel us forward. Our last prototype, Trenta, completed 10,000 high-power pulses and reached plasma temperatures of 100 million degrees Celsius (9 keV). We are now operating Polaris, our next prototype on the path to the world's first fusion power plant. This is a pivotal time to join Helion. You will tackle real-world challenges with a team that prizes urgency, rigor, ownership, and a commitment to delivering hard truths – values essential to achieving what no one has before. Together, we will change the future of energy, because the world can't wait. Helion is hiring an Experimental Scientist to own the development of Helion’s RF pre-ionization capability for our FRC system. In this role, you will develop, optimize, and validate a high-performance RF plasma source to achieve targeted plasma density, stability, and coupling efficiency. You will lead hands-on experimental work spanning RF hardware, antenna/coupling design, diagnostics, and operational procedures to deliver repeatable plasma startup. You will work closely with plasma physics, pulsed power, mechanical, controls, and operations teams to ensure the source performs reliably in the full system environment. This is a highly experimental, iteration-driven role where you will use data to diagnose issues, drive design changes, and rapidly validate improvements. This is an onsite role based in Everett, WA and reports to the Director of Experimental Science.

Requirements

Ph.D. in plasma physics, applied physics, electrical engineering, or related discipline with a strong experimental focus
Hands-on experience developing and troubleshooting RF plasma sources (ICP, CCP, helicon or similar acceptable)
Demonstrated ability to design, execute, and iterate on experimental hardware in a fast-paced R&D environment
Strong understanding of RF coupling concepts and the practical realities of integrating RF systems into complex machines
Proficiency with experimental data analysis (diagnostics interpretation, parameter sweeps, uncertainty-aware decision making)
Track record of cross-functional collaboration and technical ownership from concept through integration, testing, and validation

Responsibilities

Develop, optimize, and validate a RF plasma source for pre-ionization, integrated with Helion’s FRC system
Design and iterate RF-facing hardware (e.g., antenna geometry, coupling structures, matching approach) to improve density, stability, and coupling efficiency
Plan and execute experimental campaigns, including parameter scans, acceptance tests, and performance benchmarking against defined targets
Build and refine diagnostics and analysis methods to quantify plasma formation, density evolution, stability, and RF coupling performance
Partner with cross-functional teams (pulsed power, controls, mechanical, operations) to integrate, commission, and operate the system safely and reliably
Communicate progress through clear technical documentation and regular updates, including risks, tradeoffs, and next-step recommendations