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Senior Operations Engineer - Vacuum Systems

Commonwealth Fusion Systems

Commonwealth Fusion Systems

Operations
Devens, MA, USA
Posted on Jun 7, 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 Operations Engineer – Vacuum Systems
Commonwealth Fusion Systems is currently building the SPARC tokamak, which aims to be the first magnetic confinement device to achieve net energy and is predicted to have up to Q=11 in DT, producing up to 140 MW of fusion power. SPARC is an all-metal wall machine with tungsten and tungsten heavy alloy plasma facing components in a primary vacuum vessel, with cryogenically cooled superconducting magnets operating in a high vacuum cryostat. SPARC has multiple vacuum systems that are critical to maintaining the high and ultrahigh vacuum (HV and UHV) environments required for device operation. Coordinated operation and reliability of these vacuum systems is critical for device reliability and performance. Control of impurities and fueling in SPARC will require regular cycling of cryogenic vacuum pumps, and intermittent wall conditioning operations to improve plasma performance and reliability via combinations of high temperature vacuum bake, glow discharge cleaning, ion cyclotron discharge cleaning, and boronization. SPARC will use these systems to reduce impurities from the tokamak walls and manage main ion wall inventory, including tritium.
The Senior Operations Engineer – Vacuum Systems will develop the operational aspects of vacuum and wall conditioning on SPARC, providing input to finalize system designs and lead the planning for use of these systems during SPARC operation. During SPARC campaigns, the role will directly lead vacuum and wall conditioning operations and serve as a key member of the scientific team on SPARC.

What you'll do:

  • Develop control narratives and state machines for primary and cryostat vacuum system operations.
  • Develop control narratives and state machines for vacuum bake, glow discharge and Ion Cyclotron Discharge Cleaning, and boronization wall conditioning operations.
  • Develop operational plans and procedures for commissioning and normal operation of vacuum and wall conditioning systems.
  • In collaboration with diagnostics and fueling teams, develop the operational metrics and processes to determine the efficacy of wall conditioning operations in support of plasma operations and tritium recovery
  • In collaboration with diagnostics and fueling teams, develop a framework and procedure for gas balance measurements on SPARC and maintain estimates of tritium retention in the tokamak vacuum vessel structures
  • Support and guide various engineering and technical teams through the commissioning, testing, and validation of SPARC vacuum and wall conditioning system hardware and instrumentation.
  • Develop the concept of operations and operational requirements for ARC vacuum and wall conditioning systems

What we’re looking for:

  • Bachelors in mechanical engineering, plasma physics, or a closely related field
  • 3+ years experience high vacuum (HV) and ultra-high vacuum (UHV) environments
  • Deep knowledge of wall conditioning science and operation on plasma confinement devices
  • A desire for active participation in tokamak design and operations
  • Ability to adapt to a rapidly changing environment
  • Ability to work with collaborations from a variety of academic institutions

Bonus points for:

  • MS in experimental plasma physics or a closely related field
  • Experience with gas balance measurements and particle inventory tracking
  • Experience with Python
  • Experience with state machine control systems
  • Experience with boronization of a plasma confinement device
  • Experience in operation of vacuum systems on tokamaks, stellarators, or similar plasma confinement devices
  • Experience developing and executing wall conditioning processes for plasma processing or plasma confinement devices
  • Experience in operation and analysis of plasma edge or plasma-material interaction diagnostics
  • 3+ years experience in experimental fusion, plasma-material interactions, applied vacuum science research, or equivalent

Must-have Requirements:

  • Perform extended activities such as stooping, climbing, typing, standing, sitting, etc.
  • Willingness to travel or work required nights/weekends/on-call regularly
  • 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
#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.