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Senior Mechanical Engineer - Vessel Structures

Commonwealth Fusion Systems

Commonwealth Fusion Systems

Other Engineering
Devens, MA, USA
Posted on May 6, 2025
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, we’re designing and building commercially viable fusion power plants. And working with policymakers and suppliers to build the energy industry of the future.
We’re in the best position to make it happen. Since 2018, we’ve raised over $2 billion in capital – more than any other fusion energy company in the U.S.
Now we’re looking for more thinkers, doers, builders, and makers to join us. People who’ll bring new perspectives, solve tough problems, and thrive as part of a team.
If that’s you and this role fits, we want to hear from you.
Join the power movement as a Senior Mechanical Engineer - Vessel Structures
As a Mechanical Engineer for the SPARC Cryostat and Thermal Shields, you will develop optimized structural design to fit the form and function, meet the requirements, and passes the thermal and structural analysis using your analytical skills and capability to set up models and perform full analysis in ANSYS.

What you'll do:

  • Use knowledge of welding medium to large stainless-steel components for efficient joining of the components to support a reliable, geometrically precise and economically viable structure
  • Use knowledge of vacuum application in areas of standard sealing, vacuum side welding, and surface preparation/cleanliness for vacuum applications will be vital in proper detailing of the fabrication process requirements
  • Design and development of the large structures under vacuum and cryogenic temperatures
  • Use advanced CAD skills in NX for quick iterations on design and modeling
  • Offer insight and creative ideas in designs that are capable to meet the basic requirement, are simple and robust, with cost of manufacturing and lead time in mind
  • Develop design notes, technical specifications, assembly procedures and documentation necessary to fabricate and install the SPARC Cryostat and Thermal shields
  • Support procurement in the preparation and execution of the manufacturing contracts

What we’re looking for:

  • Bachelor’s Degree in Mechanical Engineering
  • 10 years of direct experience in design and development of large welded and machined structures

Bonus points for:

  • Master’s Degree with focus on Structural analysis
  • Advanced Knowledge of FEA and Ansys
  • Vacuum vessels
  • Cryogenic applications

Must-have Requirements:

  • Ability to occasionally lift up to 50 lbs
  • Perform activities such as typing, standing, or sitting for extended periods of time
  • 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
  • Willingness to travel or work required nights/weekends/on-call occasionally
#LI-Hybrid
At CFS, we excel in fast-paced environments, driven by our values of integrity, execution, impact, and self-critique. As we grow, we’re 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.