Nuclear Engineer - Diagnostics
Helion Energy
Company Overview
Helion Energy
Everett, WA, United States
2013
Approximately 350 employees (source: linkedin.com). No public revenue figures disclosed as the company is pre-commercialization.
What They Do
Helion Energy is a pioneering private fusion energy company that specializes in magneto-inertial fusion (MIF) technology. This innovative approach combines magnetic confinement for stability with inertial confinement for heating, enabling controlled fusion reactions that utilize deuterium from water and self-generated helium-3 in a closed-fuel cycle. This technology allows for direct electricity generation without the need for steam turbines, significantly enhancing efficiency (source: tsginvest.com). The company’s flagship product, the Fusion Engine, includes notable prototypes such as Trenta, which became the first private company to achieve a fuel temperature of 100 million degrees Celsius, and the seventh-generation Polaris, which aims to demonstrate net electricity generation from fusion (source: nucnet.org). Helion targets high-demand sectors, particularly tech data centers, and has secured over 50 industrial clients, focusing on long-term power purchase agreements (PPAs) rather than hardware sales (source: vizologi.com). The company differentiates itself through its compact design, aneutronic fusion for low radioactivity, and a faster commercialization timeline compared to competitors like Commonwealth Fusion Systems (source: equityzen.com).
Projects & Track Record
While Helion Energy has not yet completed any fully commercial projects, it has made significant strides with its prototypes, Trenta and Polaris, the latter of which is operational and aims to demonstrate net electricity generation from fusion (source: tsginvest.com). The company is currently focused on the Orion fusion power plant, a 50 MW facility under construction in Chelan County, Washington, which is expected to connect to the grid by 2028. This plant will supply power to Microsoft data centers through the state's primary power networks after a one-year ramp-up period (source: nucnet.org). Helion's client base includes Microsoft, with whom they announced the world's first fusion PPA in May 2023, and they have expressed interest from other major players like OpenAI's Sam Altman for large power purchases (source: equityzen.com). The company’s geographic presence is primarily in Washington state, with future expansion linked to the Orion project and potential data center grids (source: tsginvest.com).
Recent Developments
In the past two years, Helion Energy has made notable advancements, including the announcement of a 50 MW power purchase agreement with Microsoft in May 2023 (source: equityzen.com). The company began site work on the Orion plant in Chelan County in 2025, marking a significant step towards its goal of commercial fusion energy (source: nucnet.org). Additionally, Helion raised $425 million in a Series F funding round in January 2025, achieving a valuation of $5.4 billion and bringing its total funding to over $1 billion (source: tsginvest.com). Recent milestones also include a behind-the-scenes tour of the Polaris prototype and progress towards manufacturing fusion power at scale, with the fusion market projected to reach $572.75 billion by 2032 (source: equityzen.com).
Working There
Helion Energy offers a variety of roles across research and development, engineering, plasma physics, manufacturing, and leadership positions, including scientists and executives. Departments focus on critical areas such as accelerator development, E-BEAM optics, and laboratory operations (source: vizologi.com). The company is headquartered in Everett, WA, where open positions are listed, although no current jobs were shown on Y Combinator as of the latest data. The culture at Helion emphasizes rapid iteration and a transition from academic research to commercialization, fostering a team of experts in a high-stakes environment as they work towards the 2028 deployment of their fusion technology (source: tsginvest.com). While specific employee benefits are not detailed in available sources, the private nature of the company and its substantial funding suggest competitive perks typical of tech-sector startups in Washington's innovation ecosystem (source: aceventurefunds.com).
Last updated on Feb 23, 2026 | Report an issue
Job Description
We are looking for a Nuclear Engineer to develop, operate, and analyze data from diagnostic detectors for Polaris and future fusion generators. You will be part of our Radiation Safety and Nuclear Science (RaSNS) team. The facets of the RaSNS team include nuclear engineering (neutronics and particle diagnostics), radiation safety, fuel cycle engineering, and materials engineering. You will also work with our Research team (home to plasma physics and plasma diagnostics) and the Engineering team (home to generator mechanical and electrical design). You will report to the Nuclear Engineering Manager in this onsite role located at our Everett, WA office.
You Will
- Design, construct, calibrate, and operate neutron, photon, and charged particle diagnostics. Detector types include inorganic and organic scintillators, ion chambers, and activation foils
- Develop MATLAB or Python scripts to process detector output; prepare plots and analyses to present internally to the RaSNS, Research, and Test Operations team and externally at technical conferences
- Perform uncertainty quantification and error propagation
- Use ancillary skills to enhance detector development, e.g, Monte Carlo simulations or circuit/electrical design
Required Skills
- An advanced understanding of nuclear physics, including neutron interactions, photon interactions, cross sections, attenuation, radioactive decay, and other types of radiation
- 4+ years of experience constructing, operating, and analyzing the same detector. Demonstrated experience with electronic read-out design including digitizers, high-voltage supplies, and DAQs
- 4+ years of experience analyzing data, including the analysis of raw pulses (e.g, pile-up rejection and pulse shape discrimination), and uncertainty quantification and propagation
- 4+ years of experience documenting detector design, operation, and analysis scripts
- Simulation/modeling experience with a strong preference for MCNP6
- Experience working in pulsed electromagnetic and/or high EMI noise environments
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.
Compensation Range: $138K - $180K
Apply now
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Apply now
Job expired?Please let Helion Energy know you found this job on Rejobs. This will help us grow and get more people to work on renewable energy!
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About the role
March 25, 2026
Full time
Company
- Everett, United States
4+ years
UTC-07:00
