Principal Materials Design Scientist

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 play a key role in developing thermomechanical and thermohydraulic models to drive the development of next generation materials and engineered components. In this role, you will apply advanced simulation, physics‑based modeling, and materials science principles to design, evaluate, and optimize new materials for demanding thermal and mechanical environments. You will report to the Director of Materials, and this is an onsite role located at our Everett, WA office. You Will: Develop and execute thermomechanical and thermohydraulic models to predict performance, deformation, heat flux, stress, fluid–structure interactions and materials degradation and lifetime. Evaluate materials' thermophysical properties and integrate them into modeling workflows. Work closely with testing engineers to validate models against thermomechanical and thermohydraulic experiments. Interpret test data to refine models, reduce uncertainties, and drive design decisions. Design new materials, coatings, or composites optimized for high thermal loads, thermal cycling, or combined thermomechanical stresses. Recommend material compositions and microstructural features to meet performance targets. Partner with design engineering teams to integrate materials models into system level simulations. Communicate complex modeling results to nonexperts through clear visualizations, reports, and presentations. Required Skills: Master's or PhD in Materials Science, Mechanical Engineering, Nuclear Engineering, Chemical Engineering, Aerospace Engineering, or related fields. Strong background in heat transfer, fluid dynamics, thermodynamics, and solid mechanics. 8+ years of experience in thermomechanical and/or thermohydraulic simulation tools (COMSOL, ANSYS, Abaqus, OpenFOAM, etc.) 8+ years of experience with multiphysics modeling, including coupled heat transfer/fluid flow/stress problems. Proficiency in scripting languages (Python, MATLAB) for model automation, data processing, or custom solvers. Strong analytical, problem solving, and communication skills. Experience with CAD preferred. 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. #J-18808-Ljbffr