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:

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.

You Will:

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

Required Skills:

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)

Preferred Skills:

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

#LI-TM1 #LI-Onsite

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.