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Mechanical Engineer, RF Systems
Job Location:
Job Location:
Devens, MA - USA
Yearly Salary:
USD 90000 - 145000
Yearly Salary:
Posted:
29 September 2026 (Yesterday)
Posted:
Application Deadline:
27 December 2026
Application Deadline:
Vacancies:
1 Vacancy
Vacancies:
Job Summary
About Commonwealth Fusion Systems:
Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy.
Combining decades of research top talent and new technologies were designing and building commercially viable fusion power plants. And were working with policymakers suppliers and many others to build the energy industry of the future.
Were in the best position to make it happen. Since 2018 weve raised $4 billion of capital making us the largest and leading fusion company in the world.
Now were looking for more thinkers doers builders and makers to join us. People wholl bring new perspectives solve tough problems and thrive as part of a team.
If thats you and this role fits we want to hear from you.
Join the power movement as an Mechanical Engineer RF Systems
SPARC sustains fusion reactions by feeding >25MW of 120MHz RF power into the tokamak to heat the plasma to 100 million Kelvin. We need a Mechanical Engineer to design the critical physical infrastructure that routes this massive power from coax transmission lines that span the entire plant to the intricate cooling plates required for high-power electronics.
At this level you will own the physical design and integration of robust mechanical systems translating requirements into manufacturing-ready hardware. You will design everything from large-scale utility interfaces and custom bellows to sheet metal parts and custom heat sinks taking designs from ideation and CAD modeling through fabrication and direct plant integration.
For more information on the SPARC RF plant see the SPARC journal papers here:
What youll do:
- Design specialized RF Heating plant components working closely with RF Engineers. These include large-diameter coaxial transmission lines and devices such as stub tuners and RF testing loads
- Decompose high-level system requirements into actionable mechanical specifications owning the mechanical designs for the RF Heating system
- Collaborate daily with a dedicated CAD drafting team providing clear guidance to detail rigorously reviews and releases
- Partner cross-functionally with RF engineers electronics engineers process engineers and other disciplines
- Architect thermal management solutions by integrating complex water and air cooling loops directly into high-power electronics enclosures and plant systems
- Develop large sheet metal components precise mounting hardware for custom printed circuit board assemblies cold plates and more
- Perform structural loads analysis and thermal analyses to ensure design viability
What were looking for:
- Bachelors degree in Mechanical Engineering Physics or a related field
- 5 years of hands-on mechanical design experience in industrial heavy machinery high-power electronics electric vehicle or aerospace environments
- Demonstrated experience as the primary creator and owner of mechanical design architectures operating as a core design engineer
- Direct experience performing structural loads analysis and thermal analyses to validate mechanical designs
- High proficiency in 3D CAD software and creating detailed manufacturing drawings utilizing GD&T standards
- Possess a strong fundamental understanding of heat transfer structural mechanics and fluid dynamics
Bonus points for:
- Experience using Siemens NX for 3D modeling and Teamcenter for product lifecycle management and drawing release workflows
- Background decomposing complex system requirements into clear mechanical hardware specifications
- Experience designing large-scale pipe routing coaxial transmission lines flanges bellows or active water and air cooling systems
- Experience with complex electronics assemblies and the thermal management of such assemblies
- Deep familiarity with sheet metal fabrication processes machining capabilities and communicating directly with contract manufacturers
Must-have Requirements:
- Ability to lift up to 50lbs
- Perform activities such as stooping climbing standing typing or sitting for extended periods of time
- Willingness to travel or work required nights/weekends/on-call occasionally
- Work in a facility that contains industrial hazards including heat cold noise fumes strong magnets lead (Pb) high voltage high current pressure systems and cryogenics
$90000 - $145000 a year
Salary range for this full-time position equity benefits.The actual salary will depend on level location qualifications and experience. The range displayed on each job posting reflects new hire salaries for the position across all US locations.
Benefits include:
Competitive compensation with equity
13 Company-wide Holidays
Flexible vacation days
10 sick days
Generous parental leave policy
Health dental and vision insurance
401(k) with employer matching
Professional growth opportunities
Team-building activities
#LI-Onsite
At CFS we excel in fast-paced environments driven by our values of integrity execution impact and self-critique. As we grow were eager to bring on mission-driven folks who offer diverse perspectives and fresh ways to tackle challenges.
We value diversity deeply and are proud to be an equal opportunity employer by choice. We consider all qualified applicants equally regardless of race color national origin ancestry citizenship status protected veteran status religion physical or mental disability marital status sex sexual orientation gender identity or expression age or any other basis protected by law.
This role requires compliance with U.S. laws concerning the export of controlled or protected technologies or information (collectively Export Control Laws). Any offer of employment will be contingent on the need for compliance with such Export Control Laws.
Required Experience:
IC
