Principal Capacitor Engineer

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

As a Principal Capacitor Design Engineer at Helion, you will lead the design, development, and scaling of custom high-voltage, pulsed-power capacitors that are core to Helion’s fusion generators. You will own capacitor architecture from first principles through high-volume manufacturing, driving breakthroughs in energy density, reliability, and cost. You will provide deep technical leadership to engineering, manufacturing, and production teams as Helion transitions from prototype builds to the world’s first fusion power plant. You will provide technical leadership, organize work, set priorities, and advance Helion’s mission to deliver clean power in a reliable and cost-effective manner. This is an onsite role that reports directly to Senior Manager of Mechanical Engineering at our Everett, WA, office.

You Will

• Lead the full lifecycle of capacitor development—requirements definition, physics-based modeling, internal design, materials selection, prototyping, testing, and scaling into high-throughput manufacturing

• Drive the development of low-inductance, high-reliability pulsed capacitors capable of Required Skills

• Bachelor’s or Master’s degree in Engineering or Physics

• 15+ years of deep experience in pulsed-power capacitor design and manufacturing, including internal construction, low-inductance layout, simulation, materials processing, fabrication, high-voltage testing, and lifetime prediction

• Demonstrated expertise in dielectric physics: electrical/thermal aging, breakdown behavior, complex permittivity, frequency and temperature dependence, and high-field effects

• Proven ability to lead capacitor design from concept through high-volume production, including scaling throughput and establishing robust manufacturing processes

• Hands-on experience with rapid prototyping, iterative testing, and high-energy pulsed-power qualification

• Strong capability in failure analysis, thermal modeling, and performance evaluation under extreme electrical and thermal stress

• Track record of effective cross-functional collaboration with electrical engineering, manufacturing, supply chain, and production teams

• Ability to drive technical decision-making, mentor engineers, and set long-term architecture and process standards

• Strong communication skills and ability to translate complex physical and engineering concepts into actionable design directions

#LI-Onsite #LI-KL1

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.