Senior Materials Engineer, Diagnostics

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.

We are looking for a Senior Materials Engineer, Diagnostics to lead the development of materials health monitoring for Helion’s fusion generators. You will design, qualify, and deploy in-situ and ex-situ diagnostics to detect and quantify materials degradation under combined stimuli, including thermomechanical stress, radiation, high electric fields, and coolant environments.

You will work cross-functionally with Materials, Research, and Engineering teams to translate failure modes into measurable signals and integrate diagnostics into hardware and predictive models. This onsite role is based in Everett, WA.

• Develop and deploy in-situ and ex-situ diagnostics for degradation and failure in fusion-relevant materials and components (e.g., first wall, magnets, insulators, capacitors, HV interfaces, seals)

• Translate failure and degradation modes into measurable signals using sensors, inspection methods, or indirect indicators

• Design and execute coupled-stimuli experiments and post-irradiation examinations (PIE) to validate diagnostic methods

• Build test matrices and analysis plans linking microstructural evolution to sensor outputs and component performance

• Own the materials diagnostics roadmap by converting risk assessments into diagnostic requirements (what to measure, where, how often, and accuracy)

• Collaborate with design engineers to embed diagnostics into hardware and ensure compatibility with system constraints

• Partner with modeling teams to integrate diagnostic outputs into predictive models and maintenance strategies

• Productize diagnostic methods and sensors for reliable deployment in fusion environments

• Document test plans, procedures, and design guidance; communicate results, risks, and recommendations across teams

• BS with 10+ years, or MS/PhD with 5+ years, in Materials Science, Materials Engineering, Applied Physics, Nuclear Engineering, or related field

• 5+ years (with PhD or MS) or 10+ years (with BS) of experience in at least one of:

  • Materials diagnostics / NDE / SHM (strain, acoustic, optical, EM, fiberoptic, etc.).

  • Familiarity with data analysis / feature extraction for degradation detection (Python preferred).

• Experience designing and executing coupled-stimuli experiments (e.g., thermomechanical, electrothermal, irradiation with stress)

• Experience embedding or integrating sensors into structural materials (ceramics, composites, polymers, or metals)

• Experience in fusion, fission, accelerator, or high-radiation environments

• Experience with radiation effects and post-irradiation examination (PIE)

• Familiarity with high-voltage systems or safety-critical experimental environments

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