Senior Materials Chemist

About Helion 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. What You Will Be Doing: You will own the chemistry-driven understanding of how coolants and process fluids interact with materials and components. You will quantify degradation mechanisms, define compatibility limits, and develop practical mitigation strategies that improve system reliability and lifetime. This role sits at the intersection of chemistry, materials science, and hardware engineering, and directly impacts the performance and durability of Helion's fusion systems. You will report to the Materials Science Manager and this is an onsite role located at our Everett, WA office. You Will: - Quantify coolant-driven degradation and failure - Design and execute experimental programs to evaluate coolant and fluid impacts on materials, including corrosion, erosion, deposition/retention, polymer swelling/attack, and contamination transport - Develop test conditions that reflect relevant operating environments (temperature, pressure, flow, impurity levels, and cycling) - Develop and validate mitigation strategies - Drive cross-functional integration and execution Required Skills: - MS or PhD in Chemistry, Materials Chemistry, Corrosion Science, Chemical Engineering, or a related field (or equivalent practical experience) - 5+ years of experience in corrosion/electrochemistry, coolant or process fluid chemistry, materials compatibility testing, or degradation and failure analysis in demanding environments - Demonstrated ability to design experiments, analyze multi-variable datasets, and communicate actionable results to engineering teams #LI-Onsite #LI-TS1 Benefits Our total compensation package includes benefits, including but not limited to: • Medical, Dental, and Vision plans for employees and their families • 31 Days of PTO (21 vacation days and 10 sick days) • 10 Paid holidays, plus company-wide winter break • Up to 5% employer 401(k) match • Short term disability, long term disability, and life insurance • Paid parental leave and support (up to 16 weeks) • Annual wellness stipend Helion is an equal opportunity employer and value diversity at our company. We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. If you need assistance or an accommodation during the interview process, please let us know.